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Vintage threads from the first ten years

Re: Guytron GT-100 (Radical new design for tube amps?)

12/17/1997 7:33 AM
Jim S.	Re: Guytron GT-100 (Radical new design for tube amps?) Yes, I've read similar stories, told by Randall Smith himself in some interviews I've read. Actually, my understanding of this amp folklore is that the original "Princeton Boost" amps he made during the late 60's (including the one Santana tried, inspriing the Boogie name) had pretty much STOCK late-50's Bassman circuits, with no master volume or extra gain stage. (Smith said that, before he developed the high-gain preamp, he felt that the master volume control was a "failed promise" and he avoided using it in his amp mods.) However, as you might guess, for that time, hearing something akin to a Tweed Bassman's power, tone, and breakup character coming out of such a small package would have really turned musians' heads! It wasn't until a couple of years later, that Smith came up with the first Mark I-style circuit. It's interesting that Smith decided to abandon the tweed-style circuit for the balckface-style circuit when he started to design a high-gain preamp. I never heard him explain his reasoning fo this.

12/17/1997 7:33 AM

Jim S.

Re: Guytron GT-100 (Radical new design for tube amps?)

Yes, I've read similar stories, told by Randall Smith himself in some interviews I've read.

Actually, my understanding of this amp folklore is that the original "Princeton Boost" amps he made during the late 60's (including the one Santana tried, inspriing the Boogie name) had pretty much STOCK late-50's Bassman circuits, with no master volume or extra gain stage. (Smith said that, before he developed the high-gain preamp, he felt that the master volume control was a "failed promise" and he avoided using it in his amp mods.) However, as you might guess, for that time, hearing something akin to a Tweed Bassman's power, tone, and breakup character coming out of such a small package would have really turned musians' heads!

It wasn't until a couple of years later, that Smith came up with the first Mark I-style circuit. It's interesting that Smith decided to abandon the tweed-style circuit for the balckface-style circuit when he started to design a high-gain preamp. I never heard him explain his reasoning fo this.

12/18/1997 3:40 AM
Steve A.	Jim: For the pre-boogie amps Randall Smith made, was that a BF Princeton Reverb amp cabinet that he used, or the smaller tweed Princeton amps (which were just a step above the Harvard and the Champ)? Just wondering... >>>It's interesting that Smith decided to abandon the tweed-style circuit for the blackface-style circuit when he started to design a high-gain preamp. I never heard him explain his reasoning fo this.<<< Perhaps to differentiate his sound from the early Marshalls (which were based on the '59 bassman)? While bands like Cream would fill the stage with stacks of Marshalls, most of the local bands in SF in the late 60's used either Fender Twins or Dual Showmans, or Webb amps (from a local dealer who'd give or loan them the amps for the advertising value) with a stomp box almost always used for lead guitar. You rarely saw tweed amps on stage- everything was black tolex (and usually with psychedelized grill cloths!) I think that what the local music scene wanted was an amp that would sound like a BF Fender overdriven with a stomp box, and that was the market that Randall Smith was designing his amps for initially. (Speaking of tweed amps, I bought a circa 1960 tweed Fender Deluxe for $100 in 1967 from Leo's Music in Oakland, but traded it back in for $50 the next year because I wanted an amp with reverb!) Steve Ahola

12/18/1997 3:40 AM

Steve A.

Jim:

For the pre-boogie amps Randall Smith made, was that a BF Princeton Reverb amp cabinet that he used, or the smaller tweed Princeton amps (which were just a step above the Harvard and the Champ)? Just wondering...

>>>It's interesting that Smith decided to abandon the tweed-style circuit for the blackface-style circuit when he started to design a high-gain preamp. I never heard him explain his reasoning fo this.<<<

Perhaps to differentiate his sound from the early Marshalls (which were based on the '59 bassman)? While bands like Cream would fill the stage with stacks of Marshalls, most of the local bands in SF in the late 60's used either Fender Twins or Dual Showmans, or Webb amps (from a local dealer who'd give or loan them the amps for the advertising value) with a stomp box almost always used for lead guitar. You rarely saw tweed amps on stage- everything was black tolex (and usually with psychedelized grill cloths!) I think that what the local music scene wanted was an amp that would sound like a BF Fender overdriven with a stomp box, and that was the market that Randall Smith was designing his amps for initially. (Speaking of tweed amps, I bought a circa 1960 tweed Fender Deluxe for $100 in 1967 from Leo's Music in Oakland, but traded it back in for $50 the next year because I wanted an amp with reverb!)

Steve Ahola

12/18/1997 9:54 PM
Jim S.	I'm certain Randall Smith used blackface (and possibly silverface during the latter days of the "Princeton Boost" era) Princeton or Princeton Reverb amps (I'm not sure which). Yes, I've noticed that all of those late-60's San Francisco psychedelic bands tended to use stacks of Fender amps. I suppose back then there really weren't very many alternatives for high-wattage pro gear. I believe Marshalls were not yet being imported into the states in any significant quantity and, therefore, were virtually unobtainable. You can really hear those Californian guitar players (for example in recordings of Janis Joplin with Big Brother and the Holding Company) struggling to get the kind of tone and sustain that Clapton and Hendrix were getting easily with their English Marshalls. Those Fender amps were voiced for country & western and surf music, not hard blues-based rock!

12/18/1997 9:54 PM

Jim S.

I'm certain Randall Smith used blackface (and possibly silverface during the latter days of the "Princeton Boost" era) Princeton or Princeton Reverb amps (I'm not sure which).

Yes, I've noticed that all of those late-60's San Francisco psychedelic bands tended to use stacks of Fender amps. I suppose back then there really weren't very many alternatives for high-wattage pro gear. I believe Marshalls were not yet being imported into the states in any significant quantity and, therefore, were virtually unobtainable. You can really hear those Californian guitar players (for example in recordings of Janis Joplin with Big Brother and the Holding Company) struggling to get the kind of tone and sustain that Clapton and Hendrix were getting easily with their English Marshalls.
Those Fender amps were voiced for country & western and surf music, not hard blues-based rock!

12/19/1997 1:06 AM
Steve A.	Jim: I remember seeing the Steve Miller Blues Band a lot in 1967 and 1968 (back when he was the only guitarist in his band) and he'd usually stack a Twin on top of a Showman(?) cab to project his sound into the audience better (a very common setup back then). He'd plug his guitar into the #1 input of the Normal channel and run a short cord from the #2 jack to the #1 input of the Vibrato channel. I tried that later on my ProReverb and it sounded like crap! (Heck- I didn't know that the two channels would be out of phase with each other...) Well, obviously the Normal channel was rewired as additional gain stage(s) for the Vibrato channel, with the #2 jack being its output. I wonder who did the mod? He had a really nice moderately over-driven blues sound with a lot of sustain which sounded a lot more authentic than Clapton's stack of Marshalls. I'm still waiting for the soundtrack to "Revolution" to come out on cd- it had some of Steve's best early recordings, like "Your Old Lady" and "Mercury Blues" (later covered by David Lindley on his debut album), along with Quicksilver and Mother Earth. Mike Bloomfield had the most authentic blues sound of any of the rock guitarists back then and I think he mainly used Fender amps, too. Some of his best work was uncredited on Barry Goldberg's "Two Jews Blues" album, which also had a few tracks with Harvey Mandel and one featuring Duane Allman on acoustic slide (I thought Duane was an old country picker who was at least 50 or 60 when I heard that tune...) Ahh- nostalgia! Actually, most of the guitarists associated with the SF scene were terrible and there are only a few bands you can listen to today that don't make you cringe from both the equipment and the playing techniques. Quicksilver and Moby Grape are notable exceptions; the Airplane and the Dead had great guitarists, but their "hits" have been played so much on the radio that I'm sure we are all sick of them! Terry Haggerty of The Sons (of Champlin) had the best chops of them all, but its kind of hard to handle listening to their lyrics which sound so preachy and dated today. Steve Ahola

12/19/1997 1:06 AM

Steve A.

Jim:

I remember seeing the Steve Miller Blues Band a lot in 1967 and 1968 (back when he was the only guitarist in his band) and he'd usually stack a Twin on top of a Showman(?) cab to project his sound into the audience better (a very common setup back then). He'd plug his guitar into the #1 input of the Normal channel and run a short cord from the #2 jack to the #1 input of the Vibrato channel. I tried that later on my ProReverb and it sounded like crap! (Heck- I didn't know that the two channels would be out of phase with each other...) Well, obviously the Normal channel was rewired as additional gain stage(s) for the Vibrato channel, with the #2 jack being its output. I wonder who did the mod? He had a really nice moderately over-driven blues sound with a lot of sustain which sounded a lot more authentic than Clapton's stack of Marshalls. I'm still waiting for the soundtrack to "Revolution" to come out on cd- it had some of Steve's best early recordings, like "Your Old Lady" and "Mercury Blues" (later covered by David Lindley on his debut album), along with Quicksilver and Mother Earth. Mike Bloomfield had the most authentic blues sound of any of the rock guitarists back then and I think he mainly used Fender amps, too. Some of his best work was uncredited on Barry Goldberg's "Two Jews Blues" album, which also had a few tracks with Harvey Mandel and one featuring Duane Allman on acoustic slide (I thought Duane was an old country picker who was at least 50 or 60 when I heard that tune...)
Ahh- nostalgia! Actually, most of the guitarists associated with the SF scene were terrible and there are only a few bands you can listen to today that don't make you cringe from both the equipment and the playing techniques. Quicksilver and Moby Grape are notable exceptions; the Airplane and the Dead had great guitarists, but their "hits" have been played so much on the radio that I'm sure we are all sick of them! Terry Haggerty of The Sons (of Champlin) had the best chops of them all, but its kind of hard to handle listening to their lyrics which sound so preachy and dated today.

Steve Ahola

12/27/1997 11:34 AM
Markus Torvinen	Hi guys! I am back again! So what i have in my mind... OK! I have done several tube amps like that guytron amp. BUT i have used only one EL 84. So why? This is the reason: it`s a single ended cirquit and it has all those lovely distortion harmonics what single ended power amps have. If you have two power tubes (push-pull) you loose one very good sounding part of distortion. It is hard to say it in english because i don`t know it in english but i know it in finnish. It is better to do with one EL84. Look at my amplifier: input-> ½12ax7-> gain-> ½12ax7-> 3band EQ -> EF 86-> EL84->O.T.(load at sec is 4ohm/25watt resistor)-> 6SL7-> Master volume-> 6SL7(williamson-style phase splitter) -> Master tone control (like old VOX AC-30`s CUT-control) 4 EL84`s-> O.T, -> 2 Old vox alnico speakers. That single ended EL84 also drives a reverb tank (reverb sounds like Fender reverb unit). That amp sounds now like me. BTW, Guytron design is it not radical for me but it is very radical to others. Markus Torvinen, Tampere, Finland

12/27/1997 11:34 AM

Markus Torvinen

Hi guys! I am back again!
So what i have in my mind... OK!
I have done several tube amps like that guytron amp. BUT i have used only one EL 84.
So why? This is the reason: it`s a single ended cirquit and it has all those lovely distortion harmonics what single ended power amps have.
If you have two power tubes (push-pull) you loose one very good sounding part of distortion. It is hard to say it in english because i don`t know it in english but i know it in finnish.
It is better to do with one EL84. Look at my amplifier: input-> ½12ax7-> gain-> ½12ax7-> 3band EQ -> EF 86-> EL84->O.T.(load at sec is 4ohm/25watt resistor)-> 6SL7-> Master volume-> 6SL7(williamson-style phase splitter) -> Master tone control (like old VOX AC-30`s CUT-control) 4 EL84`s-> O.T, -> 2 Old vox alnico speakers.
That single ended EL84 also drives a reverb tank (reverb sounds like Fender reverb unit).
That amp sounds now like me. BTW, Guytron design is it not radical for me but it is very radical to others.

Markus Torvinen, Tampere, Finland

12/31/1997 1:10 AM
Steve A.	Markus: What you say makes a lot of sense for distorted tones, but maybe a pair of EL84's can get a better clean tone? If that is the case, why not have two initial output sections- one w/ 1 tube and the other w/ a pair? Can you put your schematic on a web site, or e-mail it? I'd definitely like to take a look at it... Steve Ahola P.S. All 4 of my grandparents were from Finland.

12/28/1997 1:10 AM
Jim Kroger	>>> Ahh- nostalgia! Actually, most of the guitarists associated with the SF scene were terrible and there are only a few bands you can listen to today that don't make you cringe from both the equipment and the playing techniques. <<< Well, I think you have to remember that a lot of the lacking sound quality was "filled in" by various kinds of sonic-enhancement technologies pursued by the typical Haight-Ashbury concert-goer. Jim

12/28/1997 1:10 AM

Jim Kroger

>>>
Ahh- nostalgia! Actually, most of the guitarists associated with the
SF scene were terrible and there are only a few bands you can listen to
today that don't make you cringe from both the equipment and the playing
techniques.
<<<

Well, I think you have to remember that a lot of the lacking sound quality was "filled in" by various kinds of sonic-enhancement technologies pursued by the typical Haight-Ashbury concert-goer.

Jim

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