Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: teemuk on April 16, 2007, 09:12:15 AM

Title: Solid-state guitar amplifier history -thread
Post by: teemuk on April 16, 2007, 09:12:15 AM
One of my hobbies besides electronics and music has always been history so I decided to start a thread that would gather some of solid-state amplifiers. As you all likely know, there is a lot written about tube amplifiers and it’s a crying shame that so much of solid-state guitar amplifier history has been left undocumented or has been forgotten. Maybe this forum has gathered enough enthusiastic people to find the topic “sexy” enough.

In the future, I’ll be updating this post once in a while to summarize and add new information. I’m looking forward to your contributions as the timeline and details are still pretty much “lacking”.

The 50’s:
1953

1956

The 60’s:
1960

1961

1962

1963

1964

1965

1966

1967

1968

1969

The 70’s:
1970

1971

1973

1974

1975

1976

1977

The 80’s and 90’s:



Note: Plenty of the stuff presented above is based on hearsay or to history presented by companies so its accuracy is highly questioned. For example, many companies like to claim they did or invented something first. In most cases this is far from the truth. Please doublecheck all the contributed information (oe at least try to).

I have tried to keep up a detailed list of amp manufacturers up to early 1970's. I consider these companies as sort of "pioneers". In circa 1968 many application notes describing efficient and moderately inexpensive amplifier circuits were released to boost up sales of new transistor models. This caused the amount of SS amplifier manufacturers to skyrocket. Past this point it is pretty difficult to keep any track of the various companies.
Title: Re: Solid-state guitar amplifier history -thread
Post by: teemuk on May 20, 2007, 08:20:06 PM
The initial post seemed to be growing quite large so I split it... Anyway, in case there are people who are interested in this topic  - and who haven't noticed the updates - here is a chance to catch up.

Extra insights to history (and things I need more information on):

Title: Re: Solid-state guitar amplifier history -thread
Post by: lexomatic on August 19, 2007, 05:12:29 PM
i have 2 jordan amps
1) from about 1969/1970 is a one 21 reverb 1X15 combo lists 125 watts but more like 50
2) from about 1987, korean made reverb 15, which is rated at 50 watts but more like 20

i've also seen a j120 bass master combo

i've also managed to grab pics of several different models i've seen online.
Title: Re: Solid-state guitar amplifier history -thread
Post by: axehandlejack on January 17, 2008, 09:14:54 AM
you wouldn't know who would have a schematic for a univox model 65??? mine has three input jacks, 5 knobs (volume, CLIPPING, bass, treble, and reverb). 2 footswitch jacks in back. board has 12 transistors while  what looks to be 2 power transistors(or mosfets?) off board???? some people call them  model U65RD, but it only says model 65 on back! the mother board has model S-65! thank you ! AXE
Title: Re: Solid-state guitar amplifier history -thread
Post by: teemuk on January 17, 2008, 01:02:21 PM
No, I don't know. The guy who made Univox.org page might have it, there's also a forum on that site where you could enquire. Unicord manufactured the Univox amps under brand name "Honey" in Japan. I didn't find any more info about those, however - even less schematics.

The best bet with any old amp is to trace the schematic yourself (or the parts of it that you’re focusing on). It’s a few hour job but you can easily spend days in searching the schematic from Internet – and still with a good chance of having no luck. If you find one there’s another good chance that the “same” amplifier has gone through various revisions and the circuit you have under work is not really very close to schematic you found. In other words, you still have to trace down the schematic (at least partially) to be sure that you are fixing things correctly.

Univox.org has a schematic of U-65RN, which is obviously quite different circuit than the one in your amp but it can be partially very close. I've seen the PC boards of that amp and they are made in such way that the schematic should be very easy to trace down. Likely your amp is no different. Musicparts.com lists schematics of U-65R and U-65RN so the other one of them might be what you’re looking for. I wouldn’t trust that source, though; my limited experience from that company is not very good. Then again, I have a faint memory that “U-65” was released as both transistor and tube amp.

Like I said, you better just trace the schematic yourself and have it 100% accurate. After that you can share it to help other people like you.
Title: Re: Solid-state guitar amplifier history -thread
Post by: axehandlejack on January 18, 2008, 12:42:33 PM
hello,
 the u65rn has some major differances from the s-65 or the mislabeled u65rd! the transistors are samsung or sanyo, i have no way of telling but, so i was told long ago. the problem is trying to find what is "base", "emitter", and "collector" on the originals, with out a schematic i am lost. cross reference i can tell if there "pnp" or "npn" but, when buying a replacement transistor you could put it in the same way as the original and the base collector and emmiter may be in a different order than the originals!? and they cross 2 original, with 2 diff. numbers pnp's with the same number!? i believe the differance in the 2 originals was mainly how the E.B.C. were arranged(what order).the problem is with mine is half the transistors are gone(not there anymore). and the half of the remainder have been traded out.
so it would be difficult to make a schematic. this is the reason why i need one, and also i have no voltage measurements to go by!?
the u65rn schematic i can use as referance but, the transistors and cap and resistor values are quite different.
i would be glad to make a schematic if i ever could possibly get mine fixed but, what the original voltage values are, and what the original transitors were, idk?????????(only about half the transistors i know from my own personal writings from over 10 years ago i found)

oh, and i would like to add that i have tried the univox forums, with no luck at all. and i am very surprised that after all these years there is no schematic or anybody had ever made one!? i have run into people that are in need of the same schematic and thats about it!?
Title: Re: Solid-state guitar amplifier history -thread
Post by: axehandlejack on January 19, 2008, 09:38:25 AM
OK, i started on the schematic!? i am using "express sch" and i find it difficult to use mainly from the poor symbols and trying to find the correct ones!? any easier freebee's? let me know?
it will take some time but, i will putter with it a little while each day when i can. it will be two page schematic (at least), because i am trying to lay it out how it is already in the amp!
i have the power supply part done so far!
I will be needing help, and i surely need to know the 14 transistors numbers and if possible the company who made them!?
i will leave all blank for now until i get that information!?
if i can finnaly fix amp i will take voltage measurements!?
can anybody help with the transistor numbers!??
thank you! AXE
Title: Re: Solid-state guitar amplifier history -thread
Post by: axehandlejack on January 30, 2008, 05:38:18 PM
i find some amps were marked or labeled with U65RD, and later the univox logo was gone and a "stage" logo was added in the upper left front of the speaker cloth. i also read that the place in tokyo japan had burned down. and westbury amps were produced in Korea? how true that is i dont know!?
Title: Re: Solid-state guitar amplifier history -thread
Post by: axehandlejack on March 14, 2008, 04:45:03 AM
the later "STAGE" 65 amp is way differant than the ealier U65RD! they have a "bright switch" instead of "clipping". it may just be a model 65B that i have seen!!
Title: Re: Solid-state guitar amplifier history -thread
Post by: pjm on March 16, 2008, 05:26:29 AM
And a little more info on the date of Lab Series. I know for certain I bought my L5 before 1979. I have pictures of myself with it in 1978 - I'm fairly certain I bought it in 1977. (I graduated High School in `78, and played my senior year in the "jazz band" with this amp. The school year started in 1977). This was my first real amp (before that I played through a heathkit hifi amp with an orange radio shack speaker!). Gibson Labs also says it was released in '79, but that may be when they started advertising it (I remember an ad campaign with Les Paul). BTW, Still have it Still love it!! Never had a repair!
-Peter
Title: Re: Solid-state guitar amplifier history -thread
Post by: teemuk on March 16, 2008, 07:57:10 PM
Thanks for the info Peter, I have to dig further on that topic.

Meanwhile, here are few links that might interest all those who are interested in guitar amplifier history.

History of Yorkville Sound (Traynor & Sonax)
http://yorkville.com/downloads/other/yorkvillehistory.pdf
(Well written and extensive article about the history of this company.)

Vintage Randall 1970 to 1990
http://www.randall-amps.com/
(Scarce on content but has some nice pictures and some technical literature.)

Rockman: The Story (by Tom Scholz)
http://www.rockman.fr/Story/Rockman_Story.pdf
(Article about the history of Scholz Research & Development SR&D.)
Title: Re: Solid-state guitar amplifier history -thread
Post by: ylo on May 01, 2008, 04:33:44 PM
I too bought a Lab Series L5 earlier than 1979.  As I recall, it was '77.  I will try to confirm this and get back to this forum.

I have compared the L5 to my 1971 Fender Twin Reverb in terms of sound and circuits. It sounds remarkably like a Twin Reverb in side by side comparison, but provides a little more note separation and clarity. The Normal channel of the L5 is a clone of the Fender Twin Reverb in many ways.  The tone stack has the same corner points, but is designed to work at lower impedance to match opamps instead of tubes, so the R and C values differ.  I have rigged the reverb tank to run off of the Normal channel, and in this configuration, the amp excels at doing the surf music & twang thing.

The Limiter control seems to emulate the tendency of Fender BF and early SF amps to hit the wall when cranked past 4 or 5.  The distortion circuitry in the L5, which comes into play if you crank the volume but reduce the master volume, seems to be an attempt to emulate the 12AX7 / 7025 preamp distortion that you can get if you dime some of the old Fender, but of course it sounds a bit harsh and "solid state" compared to the real thing.

By the way, you can get a reasonable bluesy sound by setting the controls so that the amp just begins to distort when the limiter engages, although this takes quite a bit of tweaking.

The Reverb channel on the L5 is another story.  I'm not sure what the designers were going for here.  With the Mid control at "0" and the Multifilter at "0", the treble does not provide very much brightness.  You have to add Multifilter to get the amp into brighter territory.  The sound with the Multifilter turned up is interesting and different, but not particularly my cup of tea for most songs.  I think the Multifilter is either an attempt to make a solid body guitar sound "woody" like an acoustic or archtop, or else it is an attempt to emulate the standing wave nodes and sound of a 4 x 12 cabinet as in Marshall.  It would be interesting to get some info from the original designers about the design philosophy behind the Reverb channel.

I know a guy that distributed Lab Series amps in the late 70s, and will contact him and ask him whether he can provide some more insight on these amps.
Title: Re: Solid-state guitar amplifier history -thread
Post by: metalhead on May 05, 2008, 02:03:49 AM
Exellent post ylo! This kind of info and opinions of  certain brand of amplifiers is most interesting.
Title: Re: Solid-state guitar amplifier history -thread
Post by: mad hatter on May 05, 2008, 03:14:18 PM
AMPEG SS series of amps was introduced at the 1987 NAMM, the first NAMM after St. Louis Music bought Ampeg.  These amps weren't some sideshow or designed to be beginner budget amps.  The SS series of guitar and bass amps were the showcase of their display (in addition to the SVT) and were how St. Louis Music wanted to reintroduce Ampeg to the music market.

I have a 1989 Ampeg catalog and in it they describe the SS series of guitar amps as:
"The Ampeg SS Series amplifiers are to the lead guitarist what the SVT is to the player - Awesome"

That's how strongly the felt about the SS guitar amps.  These things weren't some bullshit joke "beginner" amps like some solid state amps are.  They were designed to be the "SVT" of guitar amps.
I think that the Ss series of guitar amps definitely lives up to that expectation

Ampeg SS-series 1987-1991.
Ampeg VH series 1991-1998.
Title: Re: Solid-state guitar amplifier history -thread
Post by: SamRacing on July 22, 2008, 02:12:51 AM
My dad was actually the national sales and promotions manager for Jordan Amplifiers. He's got quite a few stories to tell about the various bands that used their amplifiers and some of the horror stories of equipment failures and other Jordan history.
Title: Re: Solid-state guitar amplifier history -thread
Post by: silkysam on July 27, 2008, 09:29:10 AM
Here are a couple of dinosauers that I keep as a tribute to my teen years:
Title: Re: Solid-state guitar amplifier history -thread
Post by: jsb on August 30, 2008, 11:42:39 AM
1961
  • Standel releases first hybrid amplifiers. I know Bob Crooks found Standel, built and designed many of their early tube amplifier models but what about the solid-states? Did he get some design help?


I have a Standel 52J12 amp and am trying to find out some history about it.  Does anyone have any information about its history, etc.?

I took a very close look at the model/serial plate and it clearly says 52 J 12  (I put the spaces in there to clarify what the numbers/letters are).


And yes, the tone...  oh yessss, the tone...  it's auditory coitus.
Title: Re: Solid-state guitar amplifier history -thread
Post by: Jack1962 on August 31, 2008, 06:16:30 AM
Great info, great read , Thanks Teemuk


                                               Rock On
Title: Re: Solid-state guitar amplifier history -thread
Post by: Puretone on September 14, 2008, 03:59:49 PM
One of my hobbies besides electronics and music has always been history so I decided to start a thread that would gather some of solid-state amplifiers. As you all likely know, there is a lot written about tube amplifiers and it’s a crying shame that so much of solid-state guitar amplifier history has been left undocumented or has been forgotten. Maybe this forum has gathered enough enthusiastic people to find the topic “sexy” enough.

In the future, I’ll be updating this post once in a while to summarize and add new information. I’m looking forward to your contributions as the timeline and details are still pretty much “lacking”.

The 50’s:
1953
  • (Likely) the first transistor radio is unveiled by Intermetall in Düsseldord Radio fair. First commercial transistor radio, the Regency TR-1, is put to sale the next year.

1956
  • Lin introduces quasi-complementary output stage topology (this is output transformerless).
  • Paul Penfield’s article “Transistorized Guitar Amplifier” appears in July issue of Radio & Television News magazine.

The 60’s:
1960
  • Fairchild introduces planar manufacturing method.
  • Wandré’s “Bikini” and Hofner’s “Bat” guitars come with integrated all-transistor Davoli Krundaal CT642 amplifier and speaker. http://www.fetishguitars.com/html/wandre/bikini/index.html

1961
  • Standel releases first hybrid amplifiers. I know Bob Crooks found Standel, built and designed many of their early tube amplifier models but what about the solid-states? Did he get some design help?

1962
  • Kay's "Vanguard" line-up: The first all-transistor guitar amplifiers? Any info on the designers?
  • First fuzz box, Maestro FZ-1 Fuzz Tone, appears.

1963
  • Leak Stereo 30: First commercial output (and interstage) transformerless transistor (HiFi) amplifier.
  • Hagström introduces Model 1700 - also known as "GA-85". Some people think this is the first all-solid-state guitar amplifier, it's not. (And some sources state that this model was actually introduced as late as in 1965). Any info about the designers?
  • First Burns transistor amplifier. This is likely the "Orbit" model; Around this time it costed more than a new Vox AC-30.
  • Likely the first Gibson transistor amplifiers: "Starfire"-series including TR-1000RVT and TR-1000T. This information is based on to earliest catalog entry (from 1963) I've seen concerning Gibson SS amps.
  • Czechoslovakian company called Jolana introduces the "Big Beat"; a guitar with an integrated SS amplifier and a medium wave radio. The battery-powered circuit is the first reference to a completely transformerless SS guitar amp design I've seen so far.

1964
  • First Vox transistor amplifier (T-60). Any info about the designer? Tom Jennings, Dick Denney?
  • First WEM (Watkins Electric Music) transistor amplifiers emerge. The "Slave" PA system caughts a notable success but their lineup of transistor guitar amplifiers (introduced ca. 1966) can not compete with the new "rock" amplifiers.
  • First commercial digital amplifier (Sinclair’s X10 DIY kit).

1965
  • Hartley Peavey founds Peavey. Earliest amplifiers were designed by him and (ex RCA designer) Jack Sondermeyer.
  • Jennings looses control over Thomas Organ Company that switches from supplying imported UK Vox amplifiers to building their own. The transistor models are manufactured and designed at La Sepulvenda laboratories. Any info about the designers?
  • First Carvin solid-state amplifier: T-11. Carvin also introduces other transistor amplifiers such as T-12, T-4-102, T-2-101, T-151 and T-121. (http://www.carvinmuseum.com/decade/65-guitaramps.html)
  • First Standel transistor amplifiers.
  • First Selmer transistor amplifiers. (First one was likely the Taurus 60 that later changed its name and appearance becoming Saturn 60).
  • Likely the first all-solid-state Univox amplifier, BT505 bass, appears. The following years, Univox did produce a lot of hybrids but the all-solid-state guitar amplifier lineups were introduced as late as in 1971. http://www.univox.org/pics/catalogs/1965_amp_catalog4.jpg
  • First Baldwin transistor guitar amplifiers. Baldwin had just bought Burns so there were models under both Burns, Baldwin-Burns and Baldwin names. Since Baldwin originally had no expertice in making guitar amps it's needless to say that at first Burns practically just continued to manufacture its existing designs under the Baldwin name. (More information follows later in this thread).
  • Dallas transistor amplifiers appear.
  • Rolling Stones: "Satisfaction". This hit launches a craze for fuzz effects.

1966
  • Bud Ross founds Kustom. Ross was the head designer and founded Road Electronics when Kustom was sold. Road Electronics manufactured high quality transistor guitar amplifiers and later merged with Rickenbacker that produced a series of “Road” amplifiers. Ross has also manufactured police radars and (Ross) guitar pedals.
  • Fender releases their first solid-state amplifiers. These are designed by Bob Rissi and suffer from poor build-quality and field failures.
  • Gibson introduces the transistor GSS-series consisting of models: GSS50 (2x10" combo), GSS100 (head with two 2x10" cabinets) and Plus 50 ("slave"-style 2x10" combo amp). Daughter brand Epiphone introduces the "Maxima" amp, which is a GSS100 copy.
  • First Sears Silvertone transistor amplifiers appear (Models 1464, 1465 and 1466 Bass). These are manufactured by Danelectro. In 1968 the same line-up has inclusion of model 1463.
  • First Jordan transistor amplifiers.
  • Teneyck transistor amplifiers: The G-series. These are designed by Bob Teneyck who also worked for Ampeg (design of Gemini series plus patents for Ampeg's vibrato and tremolo) and designed for Sunn (see 1969 "Orion"). Next year (1967) the T-series of amplifiers is introduced.
  • Mosrite introduces their lineup of transistor amplifiers and fails commercially with the Award BG-500 “The Ventures” model..
  • First solid-state Triumph amplifiers appear.

1967
  • The Popular Electronics magazine introduces many popular and influential kits: i.e. M/M/M Instrument Amplifier.
  • Likely the first transistor Premier amplifiers are introduced. (i.e Model 5530)
  • First all-transistor Magnatone amplifiers appear.
  • Baldwin buys Gretsch.

1968
  • RCA releases application notes describing quasi-complementary and differential input stage topologies. These are highly influential and give a start for numerous small (and bigger) companies manufacturing transistor guitar amplifiers.
  • Transonic line-up from Rickenbacker: These were also designed by Bob Rissi (designer of first SS Fender amps). However, this time most mistakes of Fenders are corrected. Transonic amplifiers are high quality but fail to catch large success; they are endorsed by Steppenwolf and used by Led Zeppelin (US tour) and Jeff Beck. Rissi continues to design and build guitar amplifiers in Risson. Today Risson makes “boutique” tube gear but assumably the first amplifiers (in 70’s) were solid state.
  • First Acoustic Control Corporation transistor amplifiers are introduced. Acoustic’s designers, employees and founders are fairly well known: Steven Marks and Harvey Gerst, Russ Allee and Roger Smith (the duo later found Amplified Music Products or AMP), Steven Rabe (later found SWR), Gene Cerwinski (later founder of Cerwin-Vega) and Aspen Pittman (sales, later found Groove Tubes) are few of the most famous.
  • GMT 226A, designed by Bob Gallien, is the first instrument amplifier that uses a stacked power transistor configuration (“cascode” or “beanstalk”). The following year Carlos Santana uses the amplifier in Woodstock.
  • Tommy Gumina founds Polytone.

1969
  • First solid-state Sunn amplifier “Orion” is designed by Bob Teneyck. This amplifier is endorsed by Jimi Hendrix but proves to be a commercial disappointment due to many field failures. The following Sunn transistor amplifiers are designed by Dick MacCloud from Tektronics.
  • Fender SS Super Showman. Interesting is the fact that this was designed by Seth Lover, the inventor of humbucking pickup (and the P.A.F.-type as well). The former employee of Gibson was hired by Fender in 1967.
  • Ovation and Lawrence transistor amplifiers appear.
  • Anthony Leo's article in Electronics Australia introduces Playmaster 125 (PM125), another SS guitar amplifier kit. http://ozvalveamps.elands.com/playmaster/pm125-1pcase.jpg

The 70’s:
1970
  • (possibly?) Sears Silvertone "slant control panel" SS guitar amplifier models 1422 (originally tube), 1423, 1425, 1426, 1428 and 1431 are introduced. These are last Sears Silvertone guitar amplifiers, basically bargain bin quality and not manufactured by Danelectro. The Silvertone brand name eventually died after 1972.
  • Kustom establishes a daughter brand of amplifiers called Kasino. Daughter brands such as Krossroad or Woodson are established later. While Plush/Earth Sound Research amplifiers bear cosmetic resemblance to Kustom's products they were actually clones of Fender or Peavey tube amplifiers.

1971
  • Heathkit: Kit amplifiers TA-17, TA-16, TA-27. http://www.ntw.net/~w0ui/family_webpage/pix/music/heathkit/heath_ta17_2.jpg Any idea of designers?
  • Sunn is the first company that experiments with overdriving FET transistors. Was this an idea of Dick MacCloud?
  • Unicord (Univox) introduces "A Group" line-up of amps including U-50PAR (PA), U-150R/RX, U-65RN/RNG, U-65G, U66G, UB-250, U-4100 “Minimax”, UB-252 and U-400G. Number had nothing to do with their power rating. http://www.univox.org/pics/amps/u65rn.jpg

1973
  • First transistor Marshall amplifiers. These are JMP-series: 1994 Slave, 2077 Bass 100 and 2078 Lead 100 Combo. They are followed by more JMP-series amplifiers in 1975/6: 2098 Master Lead, 2099 Bass, 2195 Lead & Bass, 2196 Lead & Bass, 2199 Master Lead Combo, 2200 Lead Combo, 2201 Lead & Bass and 2299 Master Lead Reverb. Any information on who were the designers?

1974
  • GMT 200G is the first channel-switching amplifier
  • Unicord (Univox) introduces "Mobile Ohm" series that are equipped with load impedance selector and E.S.P (Electric Short Proof) short-circuit protection. Models: U-130 Bass, U-130L Lead, U-130PA, U-200L Lead, U-200B Bass and U-600PA. http://www.univox.org/pics/amps/u130pa.jpg

1975
  • Roland’s Jazz Chorus line-up is introduced. During the years, Roland has released at least eight or nine new versions of this amplifier - some completely different from another. Their website hints that the real model name is depicted as JC-120-xxx, where xxx is an obscure letter code not explained anywhere (i.e. JT, U, UT). Anyone has more info?
  • Marshall releases first transistor heads.

1976
  • The concept of rail-switching amplifier (class G) is introduced and used next year by Hitachi.

1977
  • Sunn Beta series is the first commercial product utilizing overdriven Logic IC stages. (Fairchild app notes discussed the concept already in 1973). The amplifier also uses IC switching circuitry instead of FETs. Any info on the designers? The "logic inverter distortion" circuit is later (1978) popularized by an article written by Craig Anderton (before his book) and used in Electro-Harmonix "Hot Tubes" pedal.
  • Unicord (Univox) introduces "Stage" amplifiers (1977 - 1980): Models 25 Lead, 65, 65B, 252 Bass, 450, 400/112, 400/210, 720/115, 720/212, 720/410, 720K (keyboard), 750B (Bass) and 740P (PA). In some cases the second number marked the speaker configuration. http://www.univox.org/pics/amps/stage_720.jpg
  • Norlin launches a line-up of Lab Series amplifiers and the next year (1980) Lab 2 Series. These are designed by a small group of people from Moog (a division of Norlin). Norlin also releases entry level line-up named "Genesis". One of the co-designers in "Lab Series" team is Dan Pearce who later starts his own company "Pearce Amplifier Systems" that builds high quality transistor amplifiers (i.e. G1 and G2R). See later section of this thread for further details. http://www.moogce.com/images/lab1.gif

The 80’s and 90’s:

  • This is the real dawn of tube pre - SS power amp -style hybrids. Products like "Legend" amplifiers or Lab Gruppen's "AXE Amp" are preferred by artists such Johnny Winter or ZZ Top.
  • Westbury amplifiers (ca. 1980 - 1982): Westbury was the company that manufactured the late Univox SS amplifier models for the Unicord company. Essentially, Westbury amplifiers just "replaced" the Unicord "Stage" amplifier line-up of the late 70's. Models were W250 Lead, W255/110, W250/115, W550 Lead, W555 Bass, W1000 Lead, W1000-M “Mini-Lead”, W1000-MF “Mini-Lead” with Fane speaker, W1005, W1005 Bass and Model 1000 Dual-Voiced Reverb Twin. http://www.univox.org/pics/amps/westbury_amp.jpg
  • TUSC "programmable tube amplifiers" (ca. 1981): These were hybrids that had a tube-based power amplifier stage. The interesting thing is that these were likely the first guitar amplifiers with DSP-based preamplifier that was able to store knob positions to switchable patches.
  • Rivera amplifiers: During his career Paul Rivera has done design work for Fender - and not only with tube gear: Transistor amplifiers like Yale, Montreaux and Studio Lead are some of his designs. Rivera has also designed amplifiers for Yamaha (G-100) and Pignose.
  • The dawn of various “tube emulation” circuits introduced by designers such as John Murphy (Carvin), Eric Pritchard (PRS & Pritchard), Sondermeyer (Peavey).
  • Early modelling and DSP amplifiers. Information?
  • Tom Scholz introduces the Walk-man inspired "Rockman" headphone guitar amplifier in 1982.
  • Tech21 introduces SansAmp in 189.


Note: Plenty of the stuff presented above is based on hearsay or to history presented by companies so its accuracy is highly questioned. For example, many companies like to claim they did or invented something first. In most cases this is far from the truth. Please doublecheck all the contributed information (oe at least try to).

I have tried to keep up a detailed list of amp manufacturers up to early 1970's. I consider these companies as sort of "pioneers". In circa 1968 many application notes describing efficient and moderately inexpensive amplifier circuits were released to boost up sales of new transistor models. This caused the amount of SS amplifier manufacturers to skyrocket. Past this point it is pretty difficult to keep any track of the various companies.

October 2002 - Blue Tone Amplifiers intorduce the PRO 30M - the best sounding solid state amp ever produced, used by Pete Townshend, Uli Jon Roth etc etc - most Guitar mags rated it the best they'd heard.  nO LONGER IN PRODUCTION....SHAME

http://www.youtube.com/watch?v=lgGA6qx2NzQ&feature=related

http://www.youtube.com/watch?v=dN2To3CSuGE&feature=related

What do you think!?
Title: Re: Solid-state guitar amplifier history -thread
Post by: steve1564 on January 12, 2009, 02:46:35 AM
you wouldn't know who would have a schematic for a univox model 65??? mine has three input jacks, 5 knobs (volume, CLIPPING, bass, treble, and reverb). 2 footswitch jacks in back. board has 12 transistors while  what looks to be 2 power transistors(or mosfets?) off board???? some people call them  model U65RD, but it only says model 65 on back! the mother board has model S-65! thank you ! AXE

while i dont have the schematic i am playing the amp right now (between keystrokes) it was the first amp i ever got. i bought it brand new at about 1977/78 at Mathew Music at roosevelt field mall. i crank up the clipping and the reverb and it still sounds so good. i plug in my guitar,mic, and drum machine and im good to go. i have written 100`s of songs on this amp. its the Model 65 50 watts 117volts. do you have this amp as well.i wish i still had the STAGE sign that was on the fron of the amp  how can you tell which 65 it is? mine just says model 65 on the back.
Title: Re: Solid-state guitar amplifier history -thread
Post by: J M Fahey on November 24, 2010, 10:03:40 PM
Blue tones are great.
Title: Re: Solid-state guitar amplifier history -thread
Post by: drobinson9 on March 14, 2011, 03:56:29 PM
Does anyone think that if the Blue Tone Pro 30M was available again, it would achieve greater success? I hear Santana uses one for recording?  Check out his interview in Guitar Player, November 2010!

I think it would be more successful now that everyone has become so used to dealing via the internet. There is still, I think, a demand for a superior sounding SS amp, and the Blue Tone was the best of the lot
Title: Re: Solid-state guitar amplifier history -thread
Post by: drobinson9 on March 14, 2011, 03:57:24 PM
Blue tones are great.

Do you own one?
Title: Re: Solid-state guitar amplifier history -thread
Post by: J M Fahey on March 14, 2011, 07:29:56 PM
No, I don't, but I like what I hear online, plus I "buy" his approach.
I'm a minimalist myself.
I'd rather have *one* good sound rather than 256 poor ones.
Title: Re: Solid-state guitar amplifier history -thread
Post by: drobinson9 on March 15, 2011, 03:37:47 PM
Hi,

That's me playing on the Blue Tone amps youtube clips with my old ESP strat. I sold and marketed the PRO30M. The amp was designed by Alex (who plays guitar in the same band as me. Me thinks you would've loved the new design he had before we folded it - a head that could switch between the Plexi, a vintage Vox AC30, and a Fender. Tone heaven. Ah, well.....maybe one day!
Title: Re: Solid-state guitar amplifier history -thread
Post by: J M Fahey on March 15, 2011, 03:50:55 PM
Sounds good, but, why doesn't he just make a fresh batch of Pro30Ms and offers it to the general public?
If he had everything for them (PCBs, transformers, chassis designs, silkscreen, suppliers) which is the big initial investment, making "a few extra ones" carries a much lower individual cost, called "the marginal cost", which is very competitive.
He might even sell them just through EBay and maybe a personal page, no murky dealer and bank deals involved.
Title: Re: Solid-state guitar amplifier history -thread
Post by: drobinson9 on March 15, 2011, 07:24:36 PM
Well, getting them made became the problem! The company we used to assemble the amp decided to up sticks to China, and it was impossible, due to costs, to find a replacement. Very difficult, back then, to interest a Chinese manufacturer in 'small numbers', if you catch my drfit.

Manufacturing anything at all in the UK is a problem, as you are no doubt aware.

Anyway, years later, we both still gig our Blue Tones. Incidentally, the combo also included a line out which has to be heard to be believed. We've run our amps out of the line out straight into the PA on large stages and the sound that comes out of the PA has to be heard to be believed. Alex designed a great simulation for the line out. I'll post some examples of us playing live using the line out asap, if you're interested.
Title: Re: Solid-state guitar amplifier history -thread
Post by: drobinson9 on March 15, 2011, 07:38:57 PM
Here's a clip of the Blue Tone PRO30M live, with the line out through the PA. I'm on the strat and Alex, who designed the amp, is on the Gibson and lead vocals

http://www.youtube.com/watch?v=g6CQ2XQ9ZZM&feature=mfu_in_order&list=UL



Title: Re: Solid-state guitar amplifier history -thread
Post by: joecool85 on March 16, 2011, 08:08:55 AM
Wow, those Blue Tone amps do sound great!  Too bad they aren't made anymore...heck, even though I've been getting into building my own I'd still consider buying one of these.

What did they sell for new?
Title: Re: Solid-state guitar amplifier history -thread
Post by: J M Fahey on March 16, 2011, 10:08:41 AM
Quote
Well, getting them made became the problem! The company we used to assemble the amp decided to up sticks to China, and it was impossible, due to costs, to find a replacement. Very difficult, back then, to interest a Chinese manufacturer in 'small numbers', if you catch my drfit.

Manufacturing anything at all in the UK is a problem, as you are no doubt aware.
I am well aware of that.
*There is* still some Electronics going on, strong and healthy, in UK, US, most of Europe, but on specialized niches not interesting (Industrial or Medical Electronics, etc.) or off limits (Defence) for the Oriental makers, but on consumer products, forget it !!!
Last year I checked Minimum Wages worldwide, I'm from Argentina and trying to set up shop in Brazil.
While I was at it, I checked many Countries.
China? ..... "NO minimum wage" ...  xP :loco :grr
Just like that.
*BUT* on Guangdong province, to avoid abuse by foreign companies, they set a higher, guaranteed rate:
Regular workers: 39U$ cents an hour
Specialized workers: 69U$ cents an hour
Can anybody fairly compete with that?
Title: Re: Solid-state guitar amplifier history -thread
Post by: drobinson9 on March 16, 2011, 01:16:28 PM
When we ceased trading the price was £499 plus delivery. Not bad for a combo that sounds and behaves like a vintage Marshall without the hassle of valves etc. As far as I know, we haven't had a single breakdown, touch wood I even kept the bluetonesales@aol.com email open for post-sales problems, but nothing as yet (I think!). Email address is still open, lol!

Here are the youtube clips I put up a little while ago, in response to some queries - the amp also does clean up beautifully in response to changes in the volume control on your guitar.

Title: Re: Solid-state guitar amplifier history -thread
Post by: drobinson9 on March 16, 2011, 01:21:00 PM
Oooops, here are the youtube clips....

http://www.youtube.com/watch?v=dN2To3CSuGE

Done in my kitchen, recorded on a cheap Sony digital camera, but not too bad, I think.
Title: Re: Solid-state guitar amplifier history -thread
Post by: J M Fahey on March 16, 2011, 03:30:59 PM
So you needed an OEM cost for each amp, already in your warehouse, properly boxed for delivery *and* with a good, expensive Celestion to boot, of no more than £300 plus *minimum* guaranteed sales of , say, 20 units a month , just to make ends meet for a small 2 guys operation who really live out of something else.
No wonder it was difficult to keep working.
I can compare it to the excellent (in their market niche) Sessionettes, which in their time were highly regarded and sold thousands, yet could not keep the factory open after a few years.
Oh well.
Title: Re: Solid-state guitar amplifier history -thread
Post by: drobinson9 on March 16, 2011, 07:42:09 PM
Well, yes, but we would have carried on if we could have found a way of assembling the amp here in the UK, at an economical cost.

C'est la vie, eh?!
Title: Re: Solid-state guitar amplifier history -thread
Post by: joecool85 on March 17, 2011, 09:40:20 AM
Well, yes, but we would have carried on if we could have found a way of assembling the amp here in the UK, at an economical cost.

C'est la vie, eh?!

That's too bad.  Have you thought about selling the parts as kits?  Not the whole chassis with speaker etc, but at least the "guts"?  I know there are some that would be interested.
Title: Re: Solid-state guitar amplifier history -thread
Post by: J M Fahey on March 17, 2011, 01:01:12 PM
I was hinting at something similar, that's to say to reduce the sandwich size to actual mouth size.
Making a "full" commercial amplifier out of thin air is very complex (I know for sure) but taking some (really not that "special") parts away, you can chop off what's expensive yet not cost-effective to you.
In the Bluetone combo I saw, you might chop:
1) the speaker (so offering it as a head).
It's expensive and you just "pass it along".
Much worse, there will always be somebody who hates it and prefers another one.
That way, the end user can choose the speaker he prefers, from a reclaimed unknown pulled from another amp to a gold plated handbuilt by Monks in the Himalayas $3000 unit.
2) the cabinet: you may make the chassis same size as some popular Fender combo or Marshall head, for which there are tons of aftermarket builders.
You sell just the ready-to-mount working chassis , no soldering involved, just tightening 4 (supplied) bolts.
User can choose from bare chipboard to exotic wood covered in Komodo dragon skin.
I'm sure these two parts make up around 50% of the OEM cost, not being an essential part of "your sound"
3) you can use less LEDs  ;) , I'm sure that was expensive ;D
Oh well, just kidding, it's just that I love having people who do good things back in the racetrack.
Good luck.
Title: Re: Solid-state guitar amplifier history -thread
Post by: joecool85 on March 18, 2011, 08:14:37 AM
Great ideas Juan.  I'd buy a kit like what you're describing - especially if it was cost effective.
Title: Re: Solid-state guitar amplifier history -thread
Post by: Jot on March 21, 2011, 01:00:03 PM
Thanks for the ss amp history. You asked whether anyone had additional information on the Thomas Vox amplifier design. Here's a link to a fascinating letter from the designer of the Thomas Vox ss Buckingham/Viscount amp:

http://www.voxshowroom.com/us/amp/sava.html
Title: Re: Solid-state guitar amplifier history -thread
Post by: J M Fahey on March 21, 2011, 03:31:52 PM
Quote
Great ideas Juan.  I'd buy a kit like what you're describing - especially if it was cost effective.
Fine with me, now you "only" have to convince the Bluetone Guys (heyyyy !!   excellent name for a Blues/Ska band!!)  ;)
Title: Re: Solid-state guitar amplifier history -thread
Post by: drobinson9 on March 21, 2011, 05:24:43 PM
Hi, we did play the Birmingham Guitar Show 2 years running as the Blue Tone Blues Band!

The amp designer is Alex Cooper, who designs all the consoles at Midas Consoles. I think he's a bit busy at the moment, since Behringer took over Midas a little while ago!
Title: Re: Solid-state guitar amplifier history -thread
Post by: SG123 on March 25, 2011, 09:02:39 PM
Have Bruce amplifiers been mentioned?

Some info and pictures here:

http://www.tdpri.com/forum/amp-central-station/14957-bruce-amp.html
Title: Re: Solid-state guitar amplifier history -thread
Post by: Frank on April 25, 2011, 05:49:15 AM
Hi

Just found this forum yesterday. The history of solid state amps must have more mention of both the american and UK made Vox amps. These are important pieces of amp history.
In 1965 Thomas Organ Vox designed a series of ss Vox amps featuring lots of effects. These had english sounding names such as Buckingham, Westminster, Viscount, Beatle a.o. but were US made and solely sold in the US. These amps were used by many american top acts, such as Iron Butterfly and Paul Revere, and even briefly the Beatles on their last US tour.

Dick Denney of Vox UK (the proper Vox) brought home some ideas from the Thomas amps and first designed the Triumph made Vox hybrid amps 715, 730, 760, 7120, 430, 460 and 4120 with solid state pre-amps as a testing bed for the all
solid state series Vox amps of 1966. The all ss UK series, with models Traveller, Conqueror, Defiant, Supreme, Dynamic Bass, Foundation and Super Foundation are among the best sounds solid state amps of the 60'ies. They had a class A output stage and transformer, and a sophisticated pre-amp with tremolo, reverb, fuzz and mid-range boost effects. The Beatles famously used Vox Conqueror ss amps on Sgt. Pepper, Mystery Tour, Yellow Submarine and even the White Album. The Stones also used these amps.

I personally own a Conqueror and a Defiant of the late 60'ies, and they truly are fantastic sounding amps. The fuzz and overall sound is easily reckognisable as a Beatles type of sound.

There is a lot of info about these amps at http://www.voxshowroom.com/

Frank
Title: Re: Solid-state guitar amplifier history -thread
Post by: J M Fahey on April 25, 2011, 06:20:34 AM
Very interesting.
Please post some MP3s, I'd *love* to hear them played today, with modern instruments .

Title: Re: Solid-state guitar amplifier history -thread
Post by: Frank on April 25, 2011, 05:27:25 PM
I'll have to work on some samples of the clean amp sound, but for a starter here is a couple of recordings of the Vox Conqueror through its brilliant channel with the fuzz on and MRB-effect (mid-range-boost) on. Guitar is either a Washburn Falcon or an SG with humbuckers (it's a long time ago, and I don't remember for sure):

http://www.etcetera-music.eu/public/instruments/Vox/voxspec_files/lemonmix.mp3
http://www.etcetera-music.eu/public/instruments/Vox/voxspec_files/wholelo.mp3

Frank
Title: Re: Solid-state guitar amplifier history -thread
Post by: joecool85 on April 26, 2011, 09:44:37 AM
I'll have to work on some samples of the clean amp sound, but for a starter here is a couple of recordings of the Vox Conqueror through its brilliant channel with the fuzz on and MRB-effect (mid-range-boost) on. Guitar is either a Washburn Falcon or an SG with humbuckers (it's a long time ago, and I don't remember for sure):

http://www.etcetera-music.eu/public/instruments/Vox/voxspec_files/lemonmix.mp3
http://www.etcetera-music.eu/public/instruments/Vox/voxspec_files/wholelo.mp3

Frank

Wow, great tones out of such an early solid state amp.  I had it in my head that solid state guitar gear didn't start getting good till the late 80's/early 90's - you proved me wrong!
Title: Re: Solid-state guitar amplifier history -thread
Post by: LJN on April 26, 2011, 11:03:23 AM
The older the gear, the better the sound.
Title: Re: Solid-state guitar amplifier history -thread
Post by: Frank on April 29, 2011, 05:59:27 PM
Hi

I put together some more samples of the sixties classics the Vox Conqueror and the Vox Defiant:

Vox Conqueror:

Normal channel:
http://www.etcetera-music.eu/public/instruments/Vox/voxspec_files/Conqueror/Flying1.mp3

Brilliant channel with fuzz on minimum:
http://www.etcetera-music.eu/public/instruments/Vox/voxspec_files/Conqueror/LikeCreedence.mp3
Edit: I wondered why it sounds so similar to the original guitar sound. After some research, I found out that John Fogerty played a Rickenbacker 325 into a solid state Kustom K200-4, which had the same set of effects as the Vox in fac. No wonder it sounds so similar! Kustom amps must also be said to be solid state classics.

Clean brilliant channel:
http://www.etcetera-music.eu/public/instruments/Vox/voxspec_files/Conqueror/Prudence.mp3
http://www.etcetera-music.eu/public/instruments/Vox/voxspec_files/Conqueror/StrawberryFields.mp3

Brilliant channel, with fuzz and its six variations of the mid range boost (MRB) effect:
http://www.etcetera-music.eu/public/instruments/Vox/voxspec_files/Conqueror/Stones.mp3

Vox Defiant:
http://www.etcetera-music.eu/public/instruments/Vox/voxspec_files/Conqueror/Flying2.mp3

The last one is there, because Flying is suppose to have tremolo, and the tremolo on my Conqueror stopped working while I made this recording. So I switched to the Defiant (which sounds almost identical anyway). I put all the remaining instruments on today. The other guitar is also clean Defiant in brilliant channel, and the bass is played through a Vox 710 BTW.

And another important info. The guitar is in all cases a Rickenbacker 360.

Frank
Title: Re: Solid-state guitar amplifier history -thread
Post by: Rusty Chops on May 13, 2014, 11:43:56 AM
...
1971
  • Heathkit: Kit amplifiers TA-17, TA-16, TA-27. http://www.ntw.net/~w0ui/family_webpage/pix/music/heathkit/heath_ta17_2.jpg Any idea of designers?
...


Hey howdy. Cool page.

Just wanted to point out that I built a Heathkit 2 X 12" 50 watt SS combo amp in High School Shop class in 1968.

Previously I had been using a Heathkit mono Hi-Fi tube amp of perhaps 15-20 watts in a plywood box with a 12" Lafayette speaker.

The Late sixties Heathkit combo (I think the following year after I built mine there was also a 1 X 12" combo version too in the catalog) I built has 2 Jensen Special Design (blue AlNiCo) drivers and a long spring accutronics reverb tank included in the kit.

The amp also had "tremolo" (vibrato actually) with controls for speed and depth.

When I initially fired it up the reverb wasn't working (traced to a cold solder joint I had made on a ground tab on the chassis).

Once working correctly I was disappointed in the sound. It was kind of a cheap midrangey sound. I thought it must have been the speakers but no, it was just the beginnings of my education about transistor based guitar amplifiers.

Every few years I'd again try another SS amp (Baldwins with colored slide switches, Legends with cane speaker cloths in nice looking wood cabinets, Early Crates, etc).

I finally sold off my last Blackface Fender Showman head and got a Hughs&Kettner 1X12 combo, which sounded pretty good, but both it and the Randell RG80 still had that tell-tale SS junction "hiss" in the background that used to bug me.

Today (though I have a Boogie Mark I reissue), I mostly use a Roland Cube 40X in the Funk band I currently play in. Works very well and sounds great!

In the car trunk I usually keep a Starcaster 25R (same as a rebadged Fender Frontline 25R) for a spare. Sounds like an old Princeton-Reverb! ;)[/list]
Title: Re: Solid-state guitar amplifier history -thread
Post by: galaxiex on March 05, 2017, 09:58:42 PM
I have managed to acquire an old Jordan amp head.  :)

This thing is built like a tank! Heavy!

I'll do a report in a new thread when I get to fixing it. (it has some minor issues)

Here's some pics of it on my garage bench, fresh from the shipping box.

BTW, shouldn't this thread be a sticky?
Title: Re: Solid-state guitar amplifier history -thread
Post by: DrGonz78 on March 25, 2017, 06:43:03 AM
Got an old Fender Taurus solid state amp to work on here. Got it all fixed up and went to turn it on. From what I have read about all these old Fender solid state amps I expected it to just sound terrible. To my surprise it sounded absolutely fantastic!! It was absolutely silent with nearly no hum at all. It is a great clean sounding amp and I felt a need to post something to let other people out there know that it is not a terrible sounding amp. Of course someone had removed the JBL speakers so I had some old Fender 10" speakers waiting for just this problem. Somebody actually had installed car stereo speakers in the thing!  :trouble Also, the PCB board had leftover flux residue all over that had turned white. Looked like a bird had flown over it and took a dump right inside the amp. Anyway just thought to share this experience about this amp since it is a rare specimen.
Title: Re: Solid-state guitar amplifier history -thread
Post by: J M Fahey on March 25, 2017, 12:15:05 PM
Of course those sound good !!!
Excellent cleans and for dirt there´s 1000 pedals to choose from.
But tubeheads were angry when these appeared and bashed them beyond belief.

Agreed, they were not Twin Reverbs ... but then which SS amp is?
Besides Lab L5 of course ;)