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1948 Gibson Amplifiers and Pickups

Gibson model GA-30 'Invader' Amplifier was made in 1948 and was
designed by Seth Lover who invented and patented the Humbucking Pick-Up.
Seth Lover
(January 1, 1910 Kalamzoo –
January 31, 1997 in California)
is most famous for inventing the Humbucker or hum-cancelling
electric stringed instrument pickup, most often used on the electric Guitar. Lover's
most famous humbucker design (U.S.
Patent 2,896,491) was the
P.A.F. (Patent Applied For)
designed while working for Gibson
in 1955. This pickup was utilised in a range of Gibson guitars, most notably the
Les Paul model. Another of
his designs, known as the Fender Wide Range
humbucking pickup (WRHP), was used in the
three Telecaster models (Deluxe,
Custom, and
Thinline) produced by
Fender in the 1960-1970s.
The Wide Range pickup was also used in the far less popular
Fender Starcaster.
Two weeks to the day after his final appearance at the
National Association of Music Merchants show, Seth E. Lover, inventor of the
humbucker pickup, died aged 87. Before Lover,
electric guitarists were forced to cope with the 60 Cycle Hum inherent in
single coil pickups. It was in the mid-'50s, while working as an amplifier
designer at Gibson Guitars, that Lover figured out how to wire two coils
electrically out of phase and with reversed magnetic polarities. The effect was
to cancel the hum before it reached the amp and the result was the birth of the humbucking pickup.
Lover applied for the patent on the humbucking pickup in 1955
and it was finally granted in 1959 (U.S. 2,896,491). During this five-year
period, Gibson adhered a "Patent Applied For" sticker to the underside of their
humbucker pickups. These "P.A.F." pickups are the most collectable and desirable
pickups today, fetching upwards of $1,000 each among vintage guitar collectors.
While working under Ted McCarty at Gibson, Lover was also involved in guitar
design. He liked to tell how he helped contribute to the design of the famous
"Flying V." Lover said that he thought up the design as a way to lean the guitar
against a wall without it tipping over.
Lover worked for Gibson from 1952 to 1967 as a design
engineer. In 1967, he transferred to Fender Musical Instruments where he worked
until 1975 as a project engineer. In addition to his two Gibson patents, he
authored three more at Fender -- two for loudspeaker cabinets and one for an
electric piano pickup. He retired to the Southern California town of Garden
Grove where he lived quietly with Lavone, his wife of 59 years.
Seymour W. Duncan, known
industry-wide as a guitar pickup designer and manufacturer, considered Lover his
"humbucker mentor" The two were associated for nearly 20 years. In 1994,
Seymour and Seth Lover joined forces to release the Seth Lover Model pickup, an
authentic re-creation of the "Patent Applied For" humbucker. After numerous
full-page ads, NAMM show appearances, and magazine interviews, Seth became a
minor celebrity - at age 84!
Seth always maintained a quick wit and a keen sense of humour.
He was once heard joking that on his birth certificate, under the section marked
"father's name," it merely said, "Lover!" During his final years, Seth was a
regular member of the Seymour Duncan NAMM-team. He loved to hold court in the
Duncan booth answering questions and signing autographs, always with Lavone at
his side.
Seth Lover died on January 31, 1997 after a brief
illness. He is survived by Lavone, his two sons Robert and Gene, and three
grandchildren.
The humbucker pickup was invented by Seth E Lover in
1955 whilst he was working for Gibson primarily as a amplifier designer.
Lover worked for Gibson between 1952-1967 as a design engineer and was given the
task of sorting out the 60-cycle hum inherent in their P-90 design by the
management.
Using his knowledge of amplifiers, Seth Lover realised that by connecting two
singlecoil pickups in series and wiring the coils out of phase both electrically
and magnetically he could cancel out most of the hum and noise before the signal
hit the amplifier. This discovery gave the world the humbucker.
Seth and Gibson applied for the patent of this revolutionary design on june 22nd
1955. The patent wasn’t issued until July 28 1959. Around 1957 Gibson placed a
little sticker on the underside of their pickup, the famed “patent applied for”
sticker which gave the pickup it's new name - the PAF.
Interestingly Gibson received the patent in 1959 and did not change the patent
applied for sticker until roughly 1962 where it now displayed a patent number,
not for the pickup but the trapeze tailpiece designed by LES PAUL. No one knows
if this was a typo or an attempt to hide their patent from the competition.
1948 GA-30 Gibson Amplifier
Built
some two years after Django's 1946/7 American Tour this amp is barely comparable
to that which was used by Django to be heard adequately while the Duke Ellington
Orchestra wailing alongside him. His must have been a special and
who knows perhaps a prototype issued by Gibson to support their Gibson ES300
Guitar used by Reinhart throughout the tour. He wasn't well received
by the Ellington Fans who were more than discontent if the band remained silent
but for a few riffs and a crescendo during his sets. Django was lone
figure without his usual support and Ellington had not written anything special
for his unique talents, but there again Django new nothing of Key's or reading
Music Notation, didn't speak much English and always played by ear. What
an educated ear and a matchless improvisational talent!
Note the 'very large
for the times' white Amp to the left of Django with Gibson and that open
striped case at his
immediate 'left' which also appears on the La Plar Ballroom Picture with a small
black amp connection box stood on edge to the camera.
Anyone have any ideas on this
Amplification arrangement - early 'Vibrator' type power unit or pre-amp perhaps.
Was it a Seth Lover Special as it closely resembled the much later Fender Amps
in size suggesting multiple speakers.
Could the case be the controls and the large White Box just the speaker housing?
The GA 30 must have been about
24 x 18 inches say 610 x 460mm

Gibson GA-30(1948)
15Watts 1x8" & 1x12" speaker
 
The GA-30 with a
picture frame style speaker opening and dark brown leatherette covering. "New
bass tone expander control allows the player to increase resonance and quality
of the lower notes, advantageous in instrumental solo work".
First version of the series with 1-12" & 1-8" speaker. Massive
magnets made this a very heavy amp.
Has a GREAT low volume Jazz tone that is the Charlie Christian
tone all over again with the right guitar.
Early Post-WWII
Amps - Second Series and
Additions -

The short-lived GA-25 with its circular speaker openings. The case was covered
in brown Keratol - a deeply textured, dark brown leatherette. 6 tubes and "full
15 watts output". Picture courtesy of Geoff Renaud.
A new amplifier, the GA-25, was introduced in 1947. This would be the
beginning of a new series of amplifiers with model designations starting with
the letter combination GA. The GA-25 was replaced only after a year by the
GA-30. Next in the line was the GA-50 and GA-CB (1948), GA-20 and GA-75 (1950),
Gibsonette (1952), and GA-90 (1953). I'll treat the GA-40 Les Paul, introduced
in 1952 (along with a matching guitar), under a heading of its own.
The first amplifiers in this new line had the chassis mounted at the bottom
of cabinets. Gibson started to mount the chassis at the top in models introduced
in 1950 (with an exception for the Gibsonette introduced in 1952 and a couple of
other models that used two-part chassis like the GA-90).
The 6SJ7 small signal pentode was used across the whole line for the input
stages and the 6SN7 was mainly used to split the phase of the amplified signal
into the output tubes. Allthough, sometimes two 6J5 (medium mu triode) were used
instead. Tube holders were suspended in rubber to reduce microphonics.
1978 Seth E. Lover Interview on Gibson Humbucking Pickups
Interview by: Seymour W. Duncan (SWD), 6-13-78.
(This interview transcribed from audio tape.)
Location: Garden Grove, California-at the residents of Seth E. Lover -
Inventor of the Gibson “Patent Applied For” Humbucking pickups.
SWD: I guess I’ll start with where you where raised and born and
where you raised in California?
Seth Lover: I was born in Kalamazoo, Michigan at what they called
the Borgus Hospital and it’s no longer there, and a new one built
outside of town. Where I was born I believe is now the Upjohn Company.
They make drugs and so forth. I lived there till I was about 7 years old
and my parents moved to Hastings. From Hasting, Mich. I stayed there
till after World War I then we moved to Muskegon. Then in 1921 I was
sent from Muskegon I was sent to my grandparents in Pennsylvania. I
lived with them till they both died then I went to work with another guy
on a farm there and while I was still with my grandparents I built my
first radio about 1922-23. I’d been interested in radio and while I was
working on another farm I took a radio course “Radio Association of
America”. A.G. Mohawk, President I can remember that. and I was really
disappointed in that course because I was supposed to get parts to build
a large radio, instead of that I got an “Airline” radio already built.
Laugh. Less batteries & speakers. So I had a little money in the bank
and took it out to buy batteries and a speaker for it and I wanted
something I could put together.
So then I went to work for a guy who was working for an old man, he must of been
in his 60’s and it didn’t sound like a good proposition to me so I joined the
Navy. The only thing is I had to go to the local Doctor and he said I had flat
feet...Laugh, So that let me out of the Navy, I tried the Army and they accepted
me, Laugh...So I went into the Army from June of 1928 till June of 1931.
While I was in the Army I took another course, another radio course,
National Radio Institute. I got quite a bit out of that, it was a good
course. The only thing is when I joined the Army a cousin of mine went
along with me. I wanted to get in the Communications Radio section and
my cousin wanted to get in “Horse outfit”...Well I got in the Horse
outfit and my cousin got in the Communications section. We were both in
the same outfit, 16th Field Artillery. He was in the Head Quarters
Battery and I was in Battery C. That was the “Great Horse Battery” the
ones that had a show team when some high died like when ex
president Taft died I remember going to that funeral riding a horse and
we where called the escort for him. His casket was put on a cason and we
went down into Washington, DC to Union Station and took the casket over
to the church waited out there while the ceremony was going on and then
after that we came out we took him to the Arlington Cemetery and buried
him (Taft).
Then I got out of there and went back to Kalamazoo, decided to go into
the radio repair business because somewhere in the last course they
supplied me with about 100 cards saying I was a radio technician. So I
started fixing radios from about 1931 to about 1935. I either worked
with somebody or had a shop of my own...then I didn’t have enough
finance to make a go at it and took a job with the M & T battery and
Electric Company in Kalamazoo. They were the Delco Distributors of
automotive parts, car radio and at that time 32 Volt home radios. Power
plants out in the country were 32 Volts DC. You had your own home
lighting plant, there was no wires at that time and I did their auto
radio installations and repair and home radio installations & repair.
Then in the early spring of 1941, Walt Fuller at Gibson contacted me, I
had known him for quite a while, he wanted to know if I wanted to come
to work there, so we talked it over and it looked like a better future
than where I was working so I took that job (Gibson). Then in the winter
in December when the war came along, having 3 years in the Army it
wouldn’t be long before they’d be knocking at my door greeting me, I
started investigating the possibility of enlisting in the Navy. They
would take me then, flat feet and all. that I could go in as a Second
Class Radioman, which they didn’t have technicians at the time it was
Radioman, so I took that on and they sent me to Treasure Island in
California and I went through there school there and it was called Radio
Material School (RMS) and they gave us all a test when we got out
there.. I was in class 3B....we started part way along their course, we
missed a lot of basic theory that they gave to the earlier classes in 4
& 5. We went through much AC & DC theory and got into their transmitters
and receivers, sonar and radar in special service, Oh yea! when I first
went into the Navy in December of 1941 they sent us to Connecticut first
until they had enough people gathered together till Treasure Island was
ready the influx of people at the time. When we got out there in
February 1942 we had to move a bunch of bunks to get things into place.
I finished there in August and they figured they need some teachers so
they sent me and a bunch of others guys back to Chicago.. They gave us a
teachers training course, they took us 30 days, got a leave and went to
Washington, DC to Silversprings Maryland and started teaching school
there. Taught theory, lab etc. I was made 1st class I was made Chief
Petty Officer. They sent me to the Navy building to write examinations.
That was 30 days special duty and after 30 days, they renewed it for
another 30 days. That was the end of it and I was put on a ship in
Boston that wasn’t commissioned yet. Went to Boston and waited by
checking spare parts. We where on board, checked in spare parts, radio,
sonar etc.
I
was sent to Guantanamo Bay, Cuba and we made sure the ship worked we
were sent back to Boston and I was out of the Navy in October, 1945. I
went back to work for Gibson and worked for them about 8 months before
the war and, so I went back to work for them and was doing more
engineering and developed one of their pickups you’ve probably seen with
the rectangular magnets that screws up and down, individually
adjustable, it first came out on some hollow body guitar...I’ll go get
some of those pickups, I have a bunch out there in the garage...here it
is, that’s the pickup the first one’s.. shortly before this one was
brought out, DeArmond brought one out that had a very large magnet
polepiece that was adjustable up and down. It had individual screws and
Gibson felt they needed something to compete with that so I designed
this one (Alnico pickup with rectangular Alnico magnets) the polepiece
are adjustable rectangular magnet.
SWD: How was the bobbin made? Was it cut out with a routing
template.
Seth Lover: No...this is a handmade coil form made from a
rectangular piece of celluloid and we glued the ends on, drilled the
holes out and filed it out to shape to fit the rectangular magnets and
this was one of the first hand made ones made. The magnets were so
strong on this and if you got it too close to the strings, it would vary
the tone and you would get what they call “Woof” tones and that never
went over too well, I don’t know whether they made a hundred or two
hundred of them and quit.
SWD: Where all the bobbin made by hand or at that time was a
special tooling made?
Seth Lover: No unless we got into real quantity we made them by
hand, before that the ES-125 pickup eventually had a bobbin made for
that, called the P-90. The next one that I made for them was a bass
pickup. The non humbucking bass pickup with a single winding with the
magnet up one end and the screw up at the other end and between that I
designed a number of amplifiers for them. I worked for Gibson from 1945
to 47 and just designed amplifiers and no pickups at that time... at
first and designed an amplifier called the GA- 50 model if I recall and
that’s the one that had a pair of 6SJ7 tubes that were balanced and had
tremolo on it. It was the GA-50T (tremolo) you would drive your signal
into one 6SJ7 and had another 6SJ7 that was connected out of phase with
that first one and drove both of those grids with a tremolo signal, in
the plate circuit the tremolo if the circuit was equally balanced would
balance out.. I still have the schematics out there in the file cabinet
out there too and at that time the first two years after that from 45 to
47 I didn’t do any pickup work that I could recall...If I did, I don’t
remember and at that time I didn’t feel they were paying me enough and
had a chance to go back in the Navy at the training centre in Kalamazoo,
Michigan as a station keeper, I installed the radio, radar, CIC
equipment, receivers, transmitters, built a code practice table all
kinds of things to use in the training centre there and that paid better
than Gibson wanted to pay.
Then in 1952 the Navy decided it was long enough for one to stay in one
place...so I contacted Gibson and they made it worth my while to stay
there, rather than move. Ted McCarty wanted me to design a pickup for
them and that was the thing I worked on first just before I got out of
the Navy till I got out and was working full time for Gibson. I designed
the non-humbucking bass came along then somewhere along in there is when
I designed the 3 pickup job or a triple job for the steel guitars.
That’s the Humbucking pickup patent drawing (Seth is showing me the
drawings-SWD) That’s the Rhodes Piano pickup patent they still haven’t
used...maybe someday...Here it is, there are 3 rows of magnets, one all
the way across, one at the bass, one at the treble and then the
switching circuits for the switch that you added one, would be the
centre pickup by it’s self, one and two was the other pair and all, I’m
not sure...that was the neck selector, 306954, there was bass, when the
bass was added in.. that was a selector switch to give you different
connection of these coils and was filed January 9, 1957...no that was
when the patent was granted. There was one position called Chime, one
they called Treble, and I think that was Normal and Bass. There should
have been a schematic with that...lost in the shuffle.
Gibson ES 125 - 1941- 49
I
have several copies of the original humbucking patent and here’s a
speaker design patent I got while working at Fender and also a patent on
the speaker (Des. 229,289) This is a design and shows the grill cloth
and how I pulled it back in...looking from the outside it looked like a
curved linear speaker, they built the speaker but kept the front flat
and never used the design patent. Here’s the article I wrote for guitar
player magazine...this is what I wrote and sent to them and these are
the drawings I sent along and I’m still getting letters and just got one
last week...here’s the patent and how I mounted the four speakers in the
cabinet and at an angle...you know how you yell at someone across the
street and they don’t hear you and you cup your hands and that’s how the
idea came from....we fastened the screw under the Fender logo to
tightened it down.
Here’s a good copy of the patent you can have and send back when your
done. Every time they issue you a patent, their supposed to give you a
dollar...when your working for a company (Gibson) they give you a
dollar....The first dollar I ever got - I am currently working
for Logic Research Labs. Dave Love was the president and chief
engineer...they never got into production and not enough produced before
they made changes and went bankrupt. I worked for the people who took it
over. They make a mechanical Leslie sound and also make foot pedals.
Here’s the patent for the tine on the Rhodes Piano. I was able to get
the harmonics since they were unable to before. Before every time you
hit a note it would sound like “ooh ooh ooh” and have
a non-consequential sound, you get up to the treble end...sound pretty
good...you get to the bass end...sound pretty good, in the middle
register about an octave below the middle “C” and octave above middle
“C” sounded sour and didn’t sound like piano...by changing the pole
piece I was able to change it from a response of this nature to this
which when they wanted to get harmonic content they had to move the tine
closer to the middle... they could never get enough harmonic content
before they cancelled the fundamental, this one here by forcing the
magnetic field off to the sides you could get the overtones. This
particular patent they had 43 claims on it for my humbucking patent I
had one. The piano pickup patent is (3,069,954)...
In 1918 the Gibson Company built a new factory at 225
Parsons Street in Kalamazoo. The factory remained open until 1984, when the
company moved its operations to Nashville. The undated photo above depicts
workers at the Parsons Street location. During this facility’s years of
operation, Gibson greatly expanded its line, manufacturing different varieties
of mandolins, banjos, guitars, violins, ukuleles and other stringed instruments
SWD: Tell me about your humbucker.
Seth Lover: This is the original Humbucking pickup I had made and
given to the lawyers and made their drawings form that... Lover
(2,896,491)...it didn’t have to be taken apart and they asked me how it
was constructed and I told them. I had tabs folded over and was a hand
made sample that was not a production unit...later on when we started
making them I drew covers and we fastened everything together with
screws and the cover was solder fastened along the edges on the final
assembly. When you get a patent...somewhere it ways 1 claim...they
always list references cited. Here I have Lesti’s (Re. 20,070) patent
cited and a copy of Lesti’s patent and sure enough he had two pickups
and see how he did it...he had electro magnets...he’d throw the switch
one way...he applied for his in 1935 and in 1955 is when I applied for
mine...that’s when they referred mine back to his...he had humbucking
construction, he merely did it with electro magnets, he magnetized the
strings, so that was one of them...the next one was Noblaugh
(2,119,584)...he also had double coil construction so connected that it
gives humbucking action but he also applied DC...he switched back &
forth...Arnold Noblaugh...this is setting underneath the strings...I
assume that what he means by these things across here...he might have
had 16 strings...by magnetizing, one on top of the other, an iron core
flush with the top & bottom...the iron core magnetizes the strings and
the string is magnetized and moving that over a coil induces the
voltage...so that’s the way Noblaugh did it...Here’s Russell’s
(2,262,335)...patent and a horseshoe shaped magnet but he had a raised
pole pieces with the strings going through the holes....here is his U
shaped pickup and had holes in the magnet...he was first to use a
permanent magnet and the other two guys used an electromagnet....that
would have worked but at the time (1939) there were no solid body
guitars to speak of but maybe some experimental models so when you put
the weight on top of a hollow body guitar you deaden the thing...you
lose the overtones...you dampen the body...back then people who played
guitar were very fussy about what they heard and if the amplified sound
and if it didn’t sound like a guitar exactly the way, how they thought
it should sound, they’d rather be caught dead than play an electric
guitar.
Another is Alverez (2,542,271)....I don’t know why they mentioned that
one.... they say a device for creating oscillations, it didn’t have
anything to do with what I was claiming but in the early versions of the
patent application the lawyer made some reference that caused them to
dig this one out and claim it as a reference...that was filed in
48...the next is Grimshaw (2,581,653)...here is another one I couldn’t
understand why it was reference...it had a single winding and adjusting
screws on the end...in this picture and it’s still a single winding....Grimshaw
is from London, it says...something simple to manufacture employ a
minimum number of parts.. simple to assemble and adjust to require no or
very little alterations in construction of musical instrument... now his
claim he didn’t claim any humbucking action so forth and got 7
claims...just why they referenced that I don’t know... I do know that we
mentioned ours being simple so forth and maybe that what they referenced
that to....Then the next one was Keller (2,683,388)...now this looks
strangely like this one here but the coil is turned sideways, the
mounting screws slightly off centre and now why they referenced this
one, I really don’t know either....because it was a single coil, and
maybe something in the language said something the same as I did and
compared the statements and so just why it was referenced and no claim
for humbucking I don’t know....I think you can have some lawyer in
Washington search and go through the files buy when you make an
application for a patent, they search files under the same heading
“electric translating device for musical instrument” so they go through
their musical instrument file and dig through all the things and if
there’s something that references the same thing...I assume they must
have something that reads that for them. I can’t see them sitting there
reading all the patents, it would take them for ever...and this one here
since I couldn’t read it, I couldn’t find anything humbucking in
that...they were using a magnet top and bottom and could magnetize the
strings...Here is a patent of Leo Fenders (2,817,261)...shows the
Stringmaster when the volume is up all the way the pickups are in series
and humbucking...they could turn one side off when the volume control
was turned down it would use one coil...or single coil...
SWD: why do they call it an electromagnetic pickup? you usually
think of a pickup with a electrical current going through it.
Seth Lover: I don’t know why they call it electromagnetic...it’s
a generator...your changing mechanical motion and changing it into
electrical energy, it’s a generator...that’s why lot’s of times they
like using the work transducer that sounds a little more modern. I don’t
know why they use that term, there are electro magnets and permanent
magnets...anytime you change the statement in the patent that’s been
started through you must make declarations and so forth...it gets quite
fuzzy at times... I came across my original notes the other day for the
humbucking pickups...I believe the pickups (Alnico) was used on the
ES-175 and keeping the plating on the magnet it was first with copper
plated, we had the magnet copper plated then I could solder to it....the
wire was grounded to each polepiece because if somebody would happen to
touch those it would “tick”, because of capacitive coupling...your body
picks up fields that are radiated through you, if you touch something of
a different potential there is going to be an exchange of energy between
your body and another object being the pickup pole piece, like static,
since travelling from this body to that body at different potential, OK
that current is going right through the coil so it will make a little
pop...if you touch the strings you will hear the click...I’ve seen guys
play with a strap around their wrist to ground themselves to the guitar
to get away from that. I’ve heard some stories but never have
tried it myself, if you keep the bridge, strings, etc. all insulated and
don't connect the tail piece through the ground system that you get away
from that...I’ve never found a time when I could do that and never
investigated it but seemed we had more noise when isolating the
tailpiece from ground.
String
effect on a single coil (electric guitar). The coil is connected to a multimeter
that indicates the voltage changes when the string moves. This signal is
normally sent to the amplifier.
SWD: Was your first humbucker bobbins wound by hand?
Seth Lover: Yeah!
SWD: How did the tooling hold the bobbin
Seth Lover: What I have on my present one we had on the Gibson
ones, a flat plate that was connected to a shaft that was
rotating...that plate would go through here and bolts that would bolt
the system together...and this is typically what happens...they bow,
they bow at the ends from the winding pressure...the more turns you have
the more pressure they tend to give a little...and that’s one of the
things by going to a heavier plastic you can sort of tend to control
that....the prototype Alnico (staple p.u.) was wound by hand...I’m
pretty sure I wound this one myself...I believe I made this pickup
around 1952...that’s when I went back to Gibson........the first of July
of 52 got out of the Navy and went back to Gibson...I was working on
this prier to joining Gibson and when I started working full time I
finished this one up.
SWD: Did you always use 42 AWG magnet wire Plain Enamel
Seth Lover: 42 was the size wire to use if you were doing
something economically...if you go to 44 you stand more chance of
breakage and while the additional DC didn’t mean to much to you....as
long as you keep the volume control impedance at the right value, say
250K volume control you tend to load it down a little more...but if you
went smaller in size to 40 you couldn’t get enough turns on to give you
the amount of output...because the one major measure of how good a
pickup is, is how loud it is.
SWD: Why does the DC resistance vary in pickups...
Seth Lover: this one here (alnico-staple) was wound I believe
with 10,000 turns of 42 PE....I’d been trying to think how many turns I
put on the coil of a humbucking...it seemed to me it was about 6,400
turns...but than I think that it was a little high but it was in between
the 4 & 5k range...some of my earlier data suggested that I had 4,200 to
4,400 turns, then I got to thinking, didn’t I have more turns than that
on it...it seemed to me I had more turns on it. I’m not sure but I can
take this one apart and unwind it.
SWD: Are the coils made by hand in the prototype humbucker
(PAF)
Seth Lover: Yes, that’s right, the coil forms are made from
celluloid with a bar magnet underneath with iron pole pieces on each
side, you see when I first designed this I had the cover plain on the
original one...I wanted them to sell it without any adjusting screws
because I found that with this there was much difference between the
first and second strings like there is on most of the old non adjustable
type there was quite a difference in the first & second string but this
didn’t seem to have that major difference, and I thought it was not
necessary to have pole pieces...well when you take away a talking point
from a salesman it’s like breaking off your arm....the first thing I
came up with an idea was just fake some things there so I stamped them
on the cover, that didn’t please them either, by that time we already
made the patent application...that’s why it went through that way, so
they finally decided they wanted screws in there, so I put adjusting
screws in it for them, then the question they asked me then was which
way should those screws set? Should they set up or down? Well you’ve got
to give them an answer.. so I decided to take the one closest to the
fingerboard and put the screws facing it and the one closest to the
bridge towards the bridge, ...that made them happy, they had a set way
that it should be set, it only amounted to turning the pickup around...
SWD: Did you feel the screws in it would change the flow of the
magnetic field..
Seth Lover: It would change the direction of the magnetic field
out the top and also the bottom..
SWD: Did you spend a large amount of time at Gibson just
developing the humbucking pickup?
Seth Lover: Most cases I was doing other things at the same time
and I’m trying to think...let me find my note book that had my original
notes...this is electric string data that I took back in 1964, this is
core wire tinned music spring wire...nil stain winding material,
stainless steel, nickel winding material, magnetic, question mark,
source, Wilber Driver, at HK Porter. this was a part number for strings
the core was so and so, the winding was that and core was that etc. the
winding material was Nil-Stain...down here we had nickel, this was at
Gibson. Here was some ideas I had back then, see the problem with
guitars is the peg head waves around and I was trying to stabilize it
but keep it out of the way of the player, because he had to get his
hands in there to play it too, and so I was just dreaming things on
paper...This is two L 5 pickups split pickups, into three poles and the
winding turns were 10,000 and each 5250, electric mandolin pickups. I
once made a mandolin pickup, the ES-125 had 5.5 into it’s self
resonance, it was a standard than various changes I made and I attempted
to get a low impedance output.
SWD: Did you design the coil form for Gibson.
Seth Lover: Yeah. .When I designed something, I designed the
whole thing, the bobbin shape, I made an electric banjo, the solid body
electric banjo. a mixer unit.
SWD: So the first coil forms were made by hand?
Seth Lover: Oh yeah--I used celluloid...you’d mix up some acetone
and celluloid and from that you’d get a glue. That’s the way you made
your glue; you take the chips of celluloid and thin it with acetone
until it was in pasty form.
SWD: I’ve got a question for you. When a patent was issued, why
did Gibson put the number-- patent number--2,737,842 on the bottom of
the humbucker instead of your humbucking patent number 2,896,491? On the
bottom of the they use the patent number for the tailpiece instead of
your patent.
Seth Lover: That’s a good question, I don’t know. Did you get a
copy of that particular patent number they put on the bottom of the
humbucker.
SWD: Yeah. It’s their patent for the early tailpiece used on 52’
Les Paul’s and other acoustic electric instruments.
Seth Lover: I think they just got mixed up. Somebody said you
have to put patent notices on so they grabbed them out of the stock room
and put the wrong ones on. They had the Patent Applied For stickers on
till the early 60’s or so--I’m not sure exactly when they took them off
(PAF). I don’t think they used that too much after they got the patent.
It could have been, say, a year after the patent. Sometimes
manufacturers feel there’s more protection in a patent applied for
sticker than there is with the patent number because as long as there’s
a patent applied for, nobody can look at the patent and see what it
looks like. Once they have the patent number, then they can. Just how
long they use that number, I don’t know.
SWD: In 61’ there were a lot of guitars that had patent applied
for pickups and I didn’t know if they assemble all the pickups and just
stuck all the decals on or maybe they had a couple of thousand sitting
around and used them at random
Seth Lover: It’s possible. They may have had pickups manufactured
that far ahead. I think what quite often happens--you see, those guitars
are built up and come down there in racks--so many in a rack. Well, they
could get all assembled, down to the final tester and somebody testing
it, he looks it all over--gee, there’s something that doesn’t look right
in the finish--they have to send it back. So that could show up months
later, you know by the time it got around through the finishing...it
depends just how much they had to tear down and put back together to
complete that. So that could extend the life considerably.
SWD: What is the humbucker like in your terminology? What should
it be called-- electromagnetic pickup or electrogenerator?
Seth Lover: I like to call them just humbucking pickups. I call
them a generator, because that’s essentially what they are.
SWD: Did you design the coil forms (bobbins)?
Seth Lover: Yeah, in other words, that was just part of the job
when you wound the pickup you had--first you had to figure out how close
do you want that thing to sit together. And that’s going to govern,
then, the size of the coil from because just half the distance between
the pole pieces can be allotted to one half of the coil. So that’s going
to govern that.
SWD: When the bobbin had a tooling number, did Gibson issue it or
is there any reference to what it meant? This bobbin here says M69.
Seth Lover: I think that’s just a tooling number that’s put on
there by the guy who moulds the particular bobbin.
SWD: Here is a cream bobbin out of a 1963 Thunderbird bass. Why
where they using cream plastic at the time and how many would they mould
at a time. Would it be hundreds or a thousand?
Seth Lover: Oh no, there must have been several thousand at a
time. I don’t think that they ever ordered bobbins, a thousand at a
time, because it took two for each pickup and that would only be 500
pickups. 500 pickups don’t go very far. If you have two pickups on a
guitar, that’s only 250 guitars, see. That wouldn’t be too many. I know
something came up about the cream bobbin back there and I’m trying to
think clearly just what it was. I think that we felt that maybe the
cream, when you look down through the cover by the adjustable pole piece
it would not show as much as the black.. the adjusting screw side
there..and I think at one time we thought maybe that wouldn’t look,
well, I shouldn’t say objectionable, maybe it would look better if it
was cream instead of black. And then again I’m not too sure that it
wasn’t a case of the supplier calling up and saying hey, I don’t have
any black, you need these in a hurry, I can run them in cream like the
Les Paul mounting rings. Can you take them the supplier said, and in
either case I would have said yes. But we started out with black and
went to the cream for a short period of time and then back to black.
SWD: After the first bobbins you had made, were there any tooling
problems or anything you had to change in the design after you had the
bobbins made?
Seth Lover: No. I don’t recall. There was some debate at one time
whether we could make more than one spacing. The spacing-spacing of the
strings near the finger boards are different than the bridge. I wanted
to make one for each, well that meant making two moulds. So I think we
settled on one and let it fall where it would on the forward or
fingerboard pickup.
SWD: Where the coils wound by hand or was the magnet wire guided
by machine?
Seth Lover: Only the experimental ones were wound by hand. Once
we decided to make a bobbin and got our coil forms moulded, then we set
it up on the machine and I’m trying to think just how many; there was
one machine that wound just four coils. I know there was one little
machine and then we had a larger machine where we would wind more.
SWD: Was the wire guided on by hand or did it have an automatic
traverse.
Seth Lover: It had an automatic traverse. (the machine
automatically layers the magnet wire on the bobbin)
SWD: I read an article that someone said earlier humbuckers
sounded the way they do because they were wound by hand and the newer
ones were different because they were wound by machine.
Seth Lover: I can’t recall that anybody wound any by hand except
people who were repairing. I wound sometimes, and if an old pickup was
sent back in and they didn’t have a machine for winding it then it would
be rewound by hand.
SWD: Would HPI make the tooling as well as do the injection
moulding?
Seth Lover: I believe HPI made the first bobbins and they also
made the tooling for it.
SWD: Who would submit the drawing, would you do that?
Seth Lover: Oh yes. In fact those old original drawings--I don’t
have any more.
SWD: When were the first humbuckers used commercially? Early
1957
or 1967
Seth Lover: I suppose 56-57, right along in there. I know when
the patent was applied for, and there was no activity from CMI as to
wanting it put on until some trade show came along where some competitor
had a humbucking pickup. And the story came back, why don’t we have
something like that and I said “well you’ve got it hanging in there on
the wall, all you have to do is figure out how you want to make the
cover. So that brought it to a head and we went into production.
SWD: What were the first instruments if you can recall that the
humbucker was used on? Would it be the solid body or acoustic?
Seth Lover: As I recall, I could be wrong, but I think it was the
ES-350. It was not the thin one. It was the full sized body, as I
recall, and then shortly after we put it on the Les Paul solid body.
They still had the other early style, I guess, the ES 125 with the cream
cover (dog ear P-90) that was fit down in the body. And they had that on
some because people liked that particular style of pickup. And then we
added--the ES 335--that was a thin model.
SWD: How did you figure out the distance between the pickup and
the bridge, not making it too close or too far away?
Seth Lover: That was pretty much trial and error. You used what
was basically used before as the position. And you might have tried it a
little forward or a little backwards to see if you could get any
particular improvement, but I thing that it was pretty well mind set by
a musician as to the position. They liked to have certain--they thought
was correct for the pickup. And if you started fighting a musician by
moving it to some place he didn’t like you could get into trouble. Now
if you came back too close to the bridge you could get it a little
brighter, but you had a tendency to lose volume because the string
vibration did not move as far. If you lost too much volume because then
you were in the dog-house because you were not as loud; therefore, you
were not as good.
SWD: Did you have players try out the pickups before they wanted
to market them commercially?
Seth Lover: Not commercially but when you say try out--yes. We
had musicians come in and listen and try them out. We also had very good
musicians there at the plant. Julius Bellson the Production Manager was a very good
musician--Wilbur Marker - Developer, another one. They listened to them and--oh
I can remember when I was working on the first bass pickup, the non-humbucking
bass pickup--Wilbur Marker came in there each time I would get one ready
and he would try it out--”that’s better than the other, but not quite
right,” so we would make some changes and go on--wind up another. We
finally go to the point where you had to stop--you could have gone on
forever and never been exactly perfect. But, now we had some very good
years there. When I can begin to hear the differences I make certain
tests--I can hear the differences between them, and then when they would
corroborate what I could hear, then we knew we were getting somewhere.
SWD: How did you figure out the number of turns for the type of
frequency--if you put too many turns on, when do you start loosing your
high end?
Seth Lover: Well, I was just simply using # 42 plain enamel
magnet wire. I put as many turns as I could satisfactorily fill the
space available. And that’s where we stopped right there.
SWD: The pickups were designed using heavier strings than today.
Seth Lover: The pickups were designed using heavier strings with
the high E being a .012 gauge and now they use .008 which moves the
magnetic field much less. They just can’t generate enough energy with
that size string. Some players say “my pickups are weak,” if they would
only use a heavier string that the pickup was designed for they wouldn’t
have any problem. I sometimes wonder if unconsciously if guys who are
playing and bending their notes aren’t trying to get the string into
tune that don’t have it quite in tune. Unconsciously I think their ears
ought to slide a little bit higher in pitch. I’ve hear musicians talking
about things that are just bothering the hell out of them--complaining
and so forth and I’d listen and listen and I couldn’t hear. At the same
time I could hear things in there that were bothering the hell out of me
and they’d pay no attention to them. I hear something they don’t and
they hear something I don’t. What are you going to do?
SWD: We were talking earlier about how many turns were used
to--whatever could fill up the bobbin.
Seth Lover: Whatever would fill up the bobbin nicely. In
manufacturing, normally when you are winding by hand the bobbin fills a
little faster than if you have a traverse there that lays them in nice
and smooth. In other words they can get a little more in than you can
get by hand unless you are very careful about your winding, which is a
little difficult to do. People are lazy--you know you try to keep it
going as fast as you can so the job doesn’t take quite so long. Where it
builds on one side, and you have to crowd it over here and hope that it
doesn’t get squeezed on.
SWD: The wire used then was 42 AWG?
Seth Lover: 42 plain enamel.
SWD: Would the plain enamel be a single or heavy build?
Seth Lover: I think it was just a single coating.
SWD: Have you looked at the tolerance allowances that the 42 AWG
magnet wire can have?
Seth Lover: Yes. .0025” to .0029” (thousands). I don’t think that
at that time they had a thin or thick insulation. I don’t recall. I can
remember seeing wire that was double and DCC--double cotton covered.
When we had plain enamelled I don’t think that we had the thin and thick
enamel covering. My recollection is that it was just plain enamel. And
then I think possibly later on they were getting so much variation the
manufacturers were getting a little more critical so they would ask
either if I can accept the wire a little thin and the coating is a
little thinner than what we call minimal. The first thing you know the
manufacturer he would have a whole lot of one and not so much of the
other, so another guy would accept this range and not the other range,
so I kind of think they split it up that way. I could be wrong. Maybe
they’ve always had two layers or thickness available that you could buy.
Since I wasn’t doing the buying, I was merely using whatever they’d get
out of the stock room.
SWD: Would they just use one supplier?
Seth Lover: That would vary, I supposed as to then they started
bidding with different suppliers. Now I know that we’ve used Essex wire,
we’ve used Hudson, oh I’d say most of the major suppliers of magnet wire
they’ve used.
SWD: Did you ever use any other types of insulation or was it
just mainly all enamel?
Seth Lover: Back then all enamel and now they’re using a
polyurethane insulation. I’ve used polyurethane on pickups recently when
I was working at Fender and I don’t see any particular difference. The
major difference I see is sometimes if you did a little soldering and
got things a little bit too hot, it would melt, because the big reason
for using that is speed in production so they don’t have to take the
enamel off first. In fact Leo Fender never used to take the enamel of
the wire. They would wind the coils and rub the soldering iron across
the eyelet to break through the insulation. And that is one thing that
they never did at Gibson. We’d always use a little piece of sandpaper,
wipe it a couple of times and solder to it. We didn’t try to burn
through the insulation. With the early humbuckers they always started
the lead wire from inside the coil, they soldered the small, I guess 30
gauge wire to the magnet wire and extend it through the square hole on
the bottom end of the bobbin.
SWD: Did you ever get into using aluminium or silver magnet wire?
Economically it wouldn’t be too feasible.
Seth Lover: No. Since you had to have special soldering equipment
for aluminium and silver magnet wire. Back 10-15 years ago there wasn’t
too much around in the way of aluminium solder. Now days they have.
SWD: Were the coils when wound on machine wound identical? Two
bobbins, number of turns, equal traverse and tension?
Seth Lover: There was a tension adjustment for each coil. You
could have a different tension on one than the other. But normally the
girls got so they could feel that. They didn’t use meters like they do
today to measure, because those girls got so they could just sort of
lift up on the wire and feel it pulling through their hands and tell the
tension. And of course if there was too great a difference you could
immediately see it because a loose tension, the bobbin would fill up in
a hurry and couldn’t get the turns on. Then if you had a break,
sometimes they couldn’t stop that machine in time, before too many, they
didn’t notice it--one coil would break, well they’d try to stop the
machines so they could make the connection there and splice into it and
go on. Because they just strip the ends, wool them together, solder it,
fold it over, put a little piece of tape around it, so it wouldn’t touch
any of the others. Because whenever you solder like that there might be
a little sharp point of solder that would break through the additional
insulation. Lay a little wrapped tape, just fold it around there to
cover up the point and start it up and again and get going. So you could
have a coil that might have 50 or 100 less turns, depends how quickly
you stop the machine.
SWD: We talked about the addition of adjustable poles pieces;
would that change the sound any, the magnetic field-disbursed through
the bobbin?
Seth Lover: On the humbucker the adjustable pole piece extends
out the bottom. If you had a magnet that was quite weak you could absorb
some of the energy, depends on how far through that screw was, because
it’s going to absorb some of the energy there. But as a rule, with a
good magnet there wasn’t too much.
SWD: What was the reason, for having adjustable pole pieces, was
it for a better balance between string?
Seth Lover: Yes, It would give you a better balance but it was
also a selling point.
SWD: On the “patent applied for” bobbins there is a square pin
hole with a recessed ring on one end of the bobbin. What is the reason
for it?
Seth Lover: It was in the mould and I recall it was for ejecting
the bobbin. It would help pull the bobbin out of the mould.
SWD: Why didn’t they use a round vs. square.
Seth Lover: I don’t know for sure, but it was something in the
tooling that formed that square hole, as I recall. The square pin hole
would keep the bobbin from falling as the bobbin was being pulled out of
the mould. I used that hole as an exit for one of the leads. The leads
only came out the bottom. We wanted to bring the lead out at one end
from each bobbin. The beginning from the adjustable bobbin was soldered
to ground and the beginning of the stud bobbin was the hot output. The
finish of each bobbins were connected together and insulated with tape.
I never saw the tooling they moulded the bobbins on. We’d merely give
them a drawing and then they’d ask for variation to do certain things
that would help them. I’m pretty sure the mould went together this way
from the sides. At that pin at that end there turned out to be square
for some reason. I didn’t ask for a square hole. I’m sure I asked for
just a round hole. But apparently they wanted a square hole for some
reason or another. As I recall it was the mould makers request to make a
square pin hole.
SWD: The newer ones they’re making now don’t have that hole. They
have a “T” on top which they say is for winding.
Seth Lover: “T” most likely for the top of the bobbin. Making
sure they keep the “T” on top when doing assembly.
SWD: Where the bobbins made out of celluloid or nylon?
Seth Lover: No it was Buterate. It’s not celluloid. The early
P-90 and Alnico bobbins were fabricated out of celluloid and acetone.
It’s not nylon, nylon I don’t think was very popular back then. The
Firebird and Mini-Humbucker bobbins are made from nylon.
SWD: We talked about the cream bobbins being used for the
humbucker bobbins. There were double cream, black adjustable and cream
stud, black stud and cream adjustable, and double black. Why where they
made this way?
Seth Lover: They just picked the bobbins out of a bin and
assembled at random.
SWD: How many bobbins may have been run at a time?
Seth Lover: I would imagine 5-10 thousand at a time.
SWD: There are rumours going around that the black bobbin pickups
sound different than the cream bobbin pickups. How can that be possible?
Seth Lover: I can’t see that it is. The plastics are the same and
if the pole spacing changes, the magnetic field would be slightly
different on Byrdland humbucking pickups changing the sound
SWD: The Thunderbird Bass pickup was out in 1963. The bobbin was
routed down the centre and a bar magnet was inserted. Where did the
bobbin come from.
Seth Lover: We made steel guitar pickups that were humbucking
too. There were some steel guitar pickups and I don’t know if they made
thousands, maybe several hundred or something like that. The Thunderbird
bas probably used the left over bobbins they had. They were modified
steel guitar bobbins and used for the bass pickups. If you see the
bobbins you can notice the adjustable pole recess moulded into the
bobbin.
SWD: How do you feel about the price of the “Patent Applied For”
humbuckers? In the several hundred dollar category.
Seth Lover: Probably back then a pickup was made for about $5.00.
SWD: So the bobbins were put in a bin and were just picked out at
random. The creams were probably mixed in with the black ones.
Seth Lover: Chances are that’s what happened.
SWD: How did the mounting ring come about? In the drawing in your
patent...
Seth Lover: I used the old ES-125 (dog-ear cover) as a start
because we didn’t have any mounting ring for this. So this was not
acceptable as a mounting ring I felt. Because you notice this there was
a slight slope to it--slightly different here and here (neck angle). I
designed two different mounting rings. One near the bridge and one near
the fingerboard. One near the fingerboard is quite shallow at the front
edge; and, I tried to set that so the thing would have the slope of the
strings when you were fretted at the last fret. And then the one that
was back near the bridge, it had to be held up a little higher so I
wanted to bring the pickups up close to the string. Because the closer
you can keep the pickup to the string the more output you are going to
have. It doesn’t do any good to bring--to put the pickup down and bring
the screws up to compensate because you’ve lost--you’ve got to get the
pickup as close as you can to the strings.
SWD: Because your losing your magnetic field?
Seth Lover: That’s right, the magnetic field comes up to the
stings there and magnetizes the strings. That’s one of the things that
most people don’t understand. They figure that string is waving there
and cutting the magnetic lines of force. Nuts. That isn’t it. The
magnet, all it does is magnetize the string. Now you’ve got a waving
magnetic field. And we have a fixed coil with a waving magnetic field to
induce voltage. If you want to, take the magnet out. One you’ve
magnetized your strings, it will play until the string loses it. Players
think the string, the magnetic field from the magnet comes up to the
string and by twisting the magnetic flux back and forth that’s what
induces the voltage. That’s not what happens. There’s a certain amount
of that, but that’s minor. What is happening is you have a magnetic
field that is moving back and forth across the coil. And when you move a
magnetic field back and forth across the coil you induce voltage. If you
move the field up and down it wouldn’t induce any voltage. It’s the
motion back and forth across the pickup that does it.
SWD: How did you decide on the mounting ring angle?
Seth Lover: We took the standard stock guitar and added the
humbucking pickup to it and needed it to tick up a little bit to give us
some decent appearance so that meant that you had to have the front edge
thin, the back end a little thicker to get the slant you wanted on it. I
thought originally I was going to have to put two screws on each side to
keep the slant the way you want it. But for some reason the pickups tend
to take on an angle with the cover there.
SWD: Did you have to submit any changes when a player came in?
Seth Lover: If a player wanted something else, you talked about
it, maybe make a few changes before the product went out. The cover was
the only essential change. In other words I wanted it bare to start
with. Then they decided they wanted some indication of a pole piece. So
I put these rings on my prototype and that was not sufficient so we put
adjusting screws on one side.
SWD: How did you come about using alnico magnets?
Seth Lover: If I’m not mistaken I think the Oscar Moore pickup
had tungsten carbide magnets or some such name as that. In other words
what ever as the best magnet available-pre WW II (World War II) Well
after WW II alnico magnets became quite popular. They started using it
for the magnets in speakers and things like that. And finally
electrodynamics died out and we had the alnico magnets. And of course
everybody was selling speakers, selling alnico magnets and we found that
we could get alnico magnets fairly reasonable, small in size for the
amount of strength and the only thing that you run into with alnico’s
was they were cast which means if you wanted to keep a dimension you had
to pay the price for grinding the edges. And if you wanted an assembly
to fit exactly between those pole pieces, you had to make sure that your
dimensions didn’t vary too much. As cast, they ask as much as plus or
minus .030” thousands. That means as much as 16th of an inch variation.
We didn’t care about the thickness varying that much because one would
be a little bit stronger and another a little weaker. You could live
that. But the distance across the width had to have ground surfaces.
They were ground to dimensions. We tried to hold within plus or minus
.005” which is pretty tight.
SWD: What is the material and purpose of the bottom plate?
Seth Lover: The bottom plate is a non-magnetic material so that
you did not detract from the magnet. You wanted the magnet to go through
the pole pieces and the pole screw to the strings. That’s the path you
wanted the magnetism to follow. That’s why on most of those you’ll find
brass screws in the bottom. I didn’t want to detract any from the magnet
into those brass screws.
SWD: Some pickup manufacturers use steel screw to secure the
bobbins to the bottom plate.
Seth Lover: If they are willing to accept that loss, well fine.
When I designed it, I wanted brass in there. I didn’t want to take away
any of the magnetic strength in a useless point.
SWD: You like using Nickel Silver for the bottom plate and cover.
Seth Lover: Yes.
SWD: The legs on the bottom plate are L’ shaped.
Seth Lover: You had to have room for a spring so if you are going
to adjust up and down--you couldn’t have it come just straight out,
there wasn’t room enough for a spring to get any appreciable adjustment
up and down. So I brought the legs down so I could get a long enough
spring there-- so I could adjust up and down.
SWD: Did the cover that was nickel silver have a plating?
Seth Lover: I think it was nickel silver plating and they started
using gold plating--If they don’t plate too heavily, that’s fine.
Chances are they are not going to plate to heavily at the cost of gold
today.
SWD: How thick should the cover be so it works properly?
Seth Lover: I just selected a size that was easily drawable. In
other works that they could handle easily, drawing without tearing. I
would’ve like to have kept it as thin as possible. If you get it too
thin you get to many rejects when you’re drawing it. It tears easily.
SWD: Does the cover have good shielding properties?
Seth Lover: It is good for electrostatic shielding. Removing the
cover leaves a hole for electrostatic coupling.
SWD: Are the pole pieces soft iron or steel?
Seth Lover: They are soft iron pole pieces are plated to keep
them from rusting and to have a nice appearance. The little slugs are
also soft iron. You have a spacer next to the magnet which the screws go
into and is used to help hold the screw in tightly and surround the
screw with a magnetic field. It was to make sure you got a magnetic path
to the screw as much as possible. Also to have something for the screw
to adjust in. If you relied on just plastic, it would wear too easily.
SWD: The “patent applied for” magnet was 2.5” long
Seth Lover: As I recall I think it was called or #55 magnet. 2.5”
long X .5” wide X .125” thick. That was the nominal dimensions. The
length could vary +/- 16th inch--wouldn’t matter too much. The width had
to be held close to .5” if you wanted to keep your spacing right. And
the thickness, that could vary +/- 1/32nd”. You could still put the coil
assembly together.
SWD: How about the 4 brass screws? They were used to hold the
bobbins in place and to eliminate vibrations?
Seth Lover: Yes, in other words everything has to fit tight
together or if you have some possible movement of one part vs. another
you can get a pickup like a microphone--the coils tend to move or
vibrate a little, you can talk into it and hear it out of the amplifier.
SWD: Have you heard coils squeal when too close to an amp.
Seth Lover: Well the squealing part, that could be electrostatic
couplings between the speaker. Sometimes on amplifiers they do not
ground one side of the voice coil. When they do that, the voice coil
acts like a little radiating antenna and you can get electrostatic
coupling into your pickup that may cause a high pitched squealing and
quite often we were able to cure that by grounding one side of the voice
coil in the amplifier. make sure that one lug of the terminal was
grounded to the frame of the speaker. As soon as we tied the frame of
the speaker to ground, then that would tend to quiet down in most cases.
Now you can still get close enough to them where you’ll even that won’t
help you much. But then normally an acoustic electric guitar you’ll get
plain acoustic feedback or sound from the speaker will cause a howl. It
depends where your tone controls setting, to what frequency you are
tending to accentuate as to what frequency you are going to hear where
it feedback’s. It’s not a very high pitched note, it’s generally lower.
SWD: On occasion Fender had feedback problems with microphonics
at high volumes and use a wax solution to keep the components from
vibrating.
Seth Lover: When they assembled the humbucking pickups usually
they had to clamp down unit tightly until they soldered it together.
That would keep them good and tight. If they didn’t keep it tight you
could get that same condition where maybe even the magnet might vibrate
a little bit.
SWD: On many bobbins the coils are wrapped with the insulation
tape. Was that for a certain purpose.
Seth Lover: For mechanical protection
SWD: Did they always use the #4 flatback tape? It’s been used for
years and was it for a specific reason?
Seth Lover: They always used the black paper tape and I think it
was probably habit forming and then too, in other words that’s probably
what the first tape, commercially, they started using.
SWD: It works well.
Seth Lover: And it worked well for them. It’s inexpensive and
they just keep on using it because it would be just like if they changed
the color of the wire, somebody would scream, if they change the colour
of the tape--Gosh, if when they upped their Fender when they changed the
colour of the string they were wrapping them with, that was the cause of
all the problems, see?
SWD: Guitarist say “you’ve got to put that enamel wire on it!
Nothing else!, cause it won’t sound the same.”
Seth Lover: Well as long as they pay for what they get, give it
to them.
SWD: Gibson has been using the shielded, cloth braid, 7 strand
Lenz wire for a long time.
Seth Lover: Is Lenz still making wire?
SWD: At this time they still were making it.
SWD: Tell me a little bit about what you were doing at Fender.
Seth Lover: I left Gibson in 1967. Before I left there they
wanted me to take over the service department on amplifiers. So I didn’t
like the idea but I took it over. It got to be such a hassle, I said get
somebody else. I said “let me back in engineering.” And then I kind of
got the feeling at the time that they were not going to build amplifiers
too much longer. I got an inkling of a job out here at Fender. So when I
quit Gibson, I flew to California and looked the situation over and they
met the price I wanted to get. Maybe I didn’t ask enough (laugh), I
don’t know. I was happy with what I got. So I took the job and went to
work for them. Starting out, I was component evaluation and tested
speakers. I never saw so many speakers in one building in all my life.
In building 1, that was the first building Leo Fender built. That was
full of speakers to be tested. Find good speakers so they would have
speakers to replace the ones they were presently using because about
that time they were having a heck of a problem with speakers. Back
around 1967. That was about the time ceramic magnets became popular.
They had all kinds of trouble keeping those magnets on the speakers.
They would fall off inside the cabinets on their way to the customer. We
had the same trouble back at Gibson. So that was one of the problems.
And of course that’s the beginning of the high power. The boys wanted
more power, you know, and so they began driving things into distortion,
clipping and so forth. Sometimes the speakers let loose and sometimes
the guys listened to that and said the speaker rattles when it was just
clipping so badly it sounded that way. And you had to determine which
was which. And then you got to checking speakers and you found that if
you drove them at that level very long some of them would blow.
So
manufacturers had to start building speakers to handle more power. And
that’s where they got these new voice coils with aluminium lining in
there to radiate some of the heat. So my job was to test speakers and
see what would an acceptable sound and to stand the power. The next
thing I got into was the big solid state amplifier. Fender had already
started building a set of solid state stuff. Well they’d get it up to
the point where they’d start shipping and nothing would stay out in the
field. It would come back because it wouldn’t sound right, they just
wouldn’t sound like the old tube amplifiers. About 1969 I designed a
solid state amplifier for them. They wanted a three-channel. And the
specs were--this was for small groups, the bass would play in Channel 1,
Channel 2 somebody could use one of those oil can reverbs (echo’s), the
only thing is the cans are forever leaking. Channel 3 will have tremolo
and reverb for the lead guitars. Okay, that meant coming out the back
with three foot pedals. I was leery of transistors amplifiers,
transistors for some reason or another are always breaking down. Instead
of having one big, heavy power output stage, I’ll have two-70 watt
outlets. It would have 6 speakers--that was the XFL 2000. We discovered
that if a guy bought an amplifier, he was not going to let anyone else
plug into it, he wanted all these effects. Well the quickest way was to
put jumper cords on the second jack of each channel over to the first
jack. Now you were able to play using three foot pedals.
SWD: Did you design the humbucking bass pickup for Gibson?
Seth Lover: After I built the first bass pickup, it was non-humbucking.
If you ever got it near an amplifier you picked up and unduly amount of
hum. I figured the humbucking is natural for bass because that’s getting
down in the frequencies where 60 cycle hums--you’ve got 60 cycle notes
plus 60 cycle natural hum you are going to get a lot of wobble in there.
SWD: What are the line on the magnet, does that represent the
north pole?
Seth Lover: Yeah. When they’d magnetize those they’d always mark
the same side so that when they put them in a pickup, all the pickups
will be the same polarity. Since you had plenty of energy-- see this is
not the ideal way to place the coil if you want maximum efficiency. This
one here works and there’s enough turns on that thing--it seems like
20,000 turns on each coil or something like that. It worked pretty well.
Of course one of the requirements of this is that it had to fit in the
space that the old non-humbucking coils--so that was one of the designs
and configurations I had to stay with. The covering held the pickup in
place and there was some padding underneath there too.
SWD: Where all the parts manufactured outside or in house?
Seth Lover: No, a guy by the name of Watkins, as I recall,
Watkins machine shop I think made a lot of the pickup parts. He was out
of Kalamazoo and made most of the parts like the bottom plate. I think
the covers were made by some place down in Ohio, as I recall. HPI made
the bobbins but Watkins made the unit base and pole pieces. The poles in
the humbucking bass pickup would have to be removed before the plate
inside could slide through the coils. It was a lot of fun making this
type of humbucking.
SWD: What do you think about the Gibson Melody Maker pickup?
Seth Lover: It was a little inexpensive pickup that Gibson made.
They were great pickups and were really good. Like some of the higher
priced pickups, I think the ones that are simpler sounded pretty good
compared..You see they got by without having an adjustment screw and it
worked very well. They used this not only on Spanish guitars but they
used them on some of the steel guitars. Little 6 string lap steels.
SWD: Did the magnets come from Indiana General back then?
Seth Lover: Oh, I think they got some--G.E. had a magnet plant
around Midland, Michigan--somewhere up in that area. I think they
supplied them for awhile and down in Indiana--Indiana General. Then
there’s another company that I can’t recall that we got some from. I
think Gibson shopped around-when they got down low in magnets they
shopped around with the different suppliers-- whoever could supply and
make deliveries at the time that they needed them and had the best price
were the one they got them from. Because Alnico at the time was getting
pretty common-- everybody could make it and had the facilities.
SWD: Do you like reading about magnets?
Seth Lover: I’m still interested in magnetic systems. While in
the Navy they asked me what I wanted to do with my life. Of course I had
to include my own statement and I said that “I wanted to make the most
efficient electromagnetic device possible.” And whether I accomplished
it or not I don’t know.
SWD: Do you think you’ll ever pickup up your guitar and do some
playing?
Seth Lover: I’ve got several course books. I’ve got a guitar in
there, and electric guitar that I made--it’s got a doubler, dividers,
automatic Wah Wah, fuzz and you can play chords with the fuzz on it and
play chords with the divider on it.
SWD: Does most of the hum come from transformers producing a
magnetic field?
Seth Lover: Magnetic fields from transformers or if there’s a
motor running in the area, magnetic fields will come from that.
SWD: Do you still have a coil machine to work with?
Seth Lover: Yeah, I have a coil winder stuck back in the corner.
Seth Lover: Earlier you asked me the question and I thought about
it. Somewhere I have some notes on the first ideas on electric guitar
pickups--the humbucking coils. I think it started out back around 1954,
or it could have been 1955. Ted McCarty wanted a new pickup. I said
instead of just a new pickup why don’t I make some improved pickup,
something that will do something that the industry needs, which is get
rid of the darn hum whenever you got close to an amplifier.
SWD: The rest is history. Here are a few more of Seth’s patents:
- S.E. Lover: Metallic Stringed Musical Instrument.
Filed Jan. 9, 1957, Patented Dec. 25, 1962, #3,069,954.
- Ted McCarty & S.E. Lover: Patented Aug. 4, 1959,
#2,897,709, Russell Zick (Hughes Plastic).
SWD: Do you make bobbins for Gibson?
Seth Lover: Yes.
SWD: Do you know when you started working for Gibsons, we were
the first to start making bobbins for Gibson, let me get a computer
print out first.
1/15/95
transcribed 1995 by Seymour W. Duncan.

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