Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: tubenit on September 27, 2020, 07:36:24 am
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While I already have my trem-o-nator wired up to a simple mechanical on/off foot switch, I'd prefer to change that to a relay switch for the following reasons:
1) the amp already is wired with 3 relay switches so I can use one of those as a trem on/off and not have to have a second
foot switch
2) While I strongly like the trem-o-nator on "clean", I find it less useful on "overdrive". With my 3 button footswitch, I can
actually stomp on clean/overdrive and the trem on/off buttons at the same time. This would allow me to have trem
on clean but switch it off when using overdrive.
3) The reason I would like to disconnect the 50ka intensity pot instead of grounding out the trem is that the 50ka pot in
parallel with the 33k resistor lessens the volume. I would like more signal going into the 5879 tube for overdrive.
Disconnecting the 50ka pot would boost the signal going into the 5879.
However, I remember some discussion about this Vactrol being somewhat fragile??? So, I am wondering if I disconnect the 50ka intensity pot ………… is this going to damage the Vactrol? Does this vactrol need a connection there?
With respect, Tubenit
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The Vactrol is only sensitive while you are installing it. Connect the LED backwards and it's dead. Or too much heat while soldering. Otherwise it's fairly sturdy. What you want to do on the LDR side is totally safe.
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THANKS! That answers my question. I'm gonna put the on/off on the relay so I can stomp on overdrive/clean and trem on/off at the same time.
Appreciate your help and expertise as always!
Respectfully, Tubenit
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For heat sensitive parts, I use Lock Tweezers Clamp, as heat sink
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> Connect the LED backwards and it's dead.
Not 100% certain to die. Older LEDs took reverse voltage (at limited current!!) just fine. I am told newer LEDs may be easier to burn. I suspect the old-school opto-modules use old-school LEDs. I'm also not tooo worried about heat, solder or operation.
But yeah. Break that TR wire, trem won't happen, gain pops-up several dB, which seems to be what you want.
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As a side note, installing a switch to open the INT control has been a popular gain boost mod to AB763 amps for some time.
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I like the "split Resistor" version better, my brain is "seeing" a big mSec spike that's probably not audible, but is directly on the grid. But I could be all wet :dontknow:
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I like the "split Resistor" version better, my brain is "seeing" a big mSec spike that's probably not audible, but is directly on the grid. But I could be all wet :dontknow:
Yeah your probably right even though I dont remember an audible spick when I tried this like a year an half ago but then again I used a mechanical switch instead of a relay and I have a lot of make before break switches hanging around specsially foot switches.
I wasnt liking the cut only thing so I rigged it so that the gain was higher on tremelo then cut it from there so that the preceivd volume didnt drop when tremelo cut in.
I deleted my post rather than strap a 4.7M so that I wouldnt feel like wrob.
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:laugh:
when I was "Visualizing" to Grateful Dead, I missed the rather large audio signal coming in from the left, likely negating the spike
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when I was "Visualizing" to Grateful Dead, I missed the rather large audio signal coming in from the left, likely negating the spike
:w2:
On the rare occasion that I used a stomp box, I would always stomp it on a beat or an accent (especially if I thought the drummer was going to wallop a cymbal right there).
I was thinking about that possible spike from the relay. What do you think about this fix?
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my comment, I just didn't consider there would be guitar signal when you switch trem on/off. considering there IS guitar signal, my gut thinks the guitar signal will "over-ride" any switching noise.
in other-words
I'm all wet :laugh:
but the 4.7M probably won't hurt a thing, might even help "if there is a problem" :dontknow: