Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: PRR on June 03, 2022, 07:53:58 pm
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Who knows?
However the same issue has a trem amp.
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Thats a pretty unique design no? A 6SL7 tremolo? Havent seen one of those since Sluckley's version!
Cool find thanks for sharing that!
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I really love those hand drawn layouts!
Interesting coupling of the LFO into the first stage.
I have to try this, thanks!
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Thank' to share ;
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I really love those hand drawn layouts!
Interesting coupling of the LFO into the first stage.
I have to try this, thanks!
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I really love those hand drawn layouts!
Interesting coupling of the LFO into the first stage.
I have to try this, thanks!
The Watkins Dominator uses a similar shared cathode modulation arrangement. But by incorporating the trem oscillator into the other V1 section, Charlie Watkins eliminated the need for all the V2 circuitry.
My V1 and V2 references ate with regard to the EI amp, rather than the Dominator.
https://el34world.com/charts/Schematics/files/Watkins/Watkins_dominator.pdf
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[/quote]
The Watkins Dominator uses a similar shared cathode modulation arrangement. But by incorporating the trem oscillator into the other V1 section, Charlie Watkins eliminated the need for all the V2 circuitry.
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It was done by Valco in the fifties in the Tremo-Tone amp, if I remember correctly. A shared cathode with the LFO and no depht pot. Probably in one Gibson amp too.
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That Watkins Dominator tremolo circuit is identical to the Marshall 1974 18W circuit. It is the most finicky trem circuit I have ever messed with. The 18watt.com forum is full of complaints and fixes that work for one person but not another.
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Thanks PRR.
So, I had to go searching through www.americanradiohistory.com (http://www.americanradiohistory.com) myself.
I found the "Simple Guitar Amplifier" from 1/1956.
And, the guy on the cover from the same year:
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that "Simple Guitar Amplifier" actually is the Death Ray.
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you'll see and feel it if you get this wrong :icon_biggrin:
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that "Simple Guitar Amplifier" actually is the Death Ray.
There is no pilot light actually. The guitar player becomes the ''pilot light'' in the firmament (not the filament).
Anybody could join the forum to learn to convert a three prong cord into two. To be ''woke'' we must cancel old files.
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As late as 1958 you could not buy a wide/narrow plug in the hardware store. You could buy a 3-pin. But none of the outlets in a house were 3-pin. Or polarized.
And I hope we all know that any amp with a 50_5 or a 35_4 is a HOT CHASSIS DEATH TRAP. There are long arguments why this is not true in every case, but please add an isolation transformer (or build something less cheap and cheezy).
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Of course I was just being ironic in my last post/sentence. I just assumed that fellows in this forum would be able to dismiss the death trap of these old bypolar input circuits schematics as being the product of a bygone era (obviously knowing what to do to correct them) and would just rather concentrate on the interesting part of the circuit which is, in my opinion, the way the oscillator is fed into the first gain stage.
In the Watkins/Marshall circuit, it looks like the tremolo depth control could be interactive with the tone of the channel by altering the bias and make it beefier or thinner even when the effect is off and that's probably why a dedicated non-trem channel was desirable (or not).
The EI amplifier, it seems, has a better isolation of the LFO circuit. I don't know if the sound is better. The LFO circuit looks savvy but not frugal, and I don't undestand it 100% yet.
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I just learned yesterday that "As late as 1958 you could not buy a wide/narrow plug in the hardware store", so I threw that in.
I am about past caring if the youth of today suffers 110V shocks, but old habits die won't quit. (I almost said "die hard" but this has been a hard week for that.)
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I removed the PDF I had attached above. I did see how the 117AC was wired sans transformer, but I didn't really think about the possibility of someone on the internet deciding to build it.
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What happened to the Death Ray?
Many, many, many years ago in the cinemas, here with us, they projected, together with the film, a newsreel, well I was a boy but I remember well that as a death ray a tactical laser was presented and in the film you could see radio-controlled planes that were hit and crashed
So, I assume that today we call it Laser Beam
Franco
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So, I assume that today we call it Laser Beam
I believe the Navy worked out the kinks and has a few deployed on ships as short range missile killers.
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This project does have a PT, and uses a 12AU7 and a 12AX7:
"Make like Elvis with an 'electronic' throbbing guitar"
Maybe the vibrato/tremolo experts here will critique this design.
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I just learned yesterday that "As late as 1958 you could not buy a wide/narrow plug in the hardware store", so I threw that in.
I am about past caring if the youth of today suffers 110V shocks, but old habits die won't quit. (I almost said "die hard" but this has been a hard week for that.)
On the bright side, deepening the gene pool might not be such a bad thing. Hmmmmm........amp builds gone bad.......Now, where is that point and laugh emoji? ;^)