10 MEG POTS?
Geoff W
building a couple of tremolo circuits based on the early 60s Fender
circuits that used these values. ORiginally they seem to have used
reverse audio taper but I suspect I'd be dreaming to find these so
linear would have to do the job, if I can find them!
nuke
the component parameters a bit, but it will work essentially the same.
--
Dr. Nuketopia
Spam filtering is off. AO-Hell catches most of it now.
Leo
>Just use the 3 meg RA pots from the BF-era oscillator circuit. You can tweek
>the component parameters a bit, but it will work essentially the same.
>
>>Can anybody tell me where I can purchase 10 MEG and 4 MEG pots, I am
>>building a couple of tremolo circuits based on the early 60s Fender
>>circuits that used these values. ORiginally they seem to have used
>>reverse audio taper but I suspect I'd be dreaming to find these so
>>linear would have to do the job, if I can find them!
If anybody needs 3m pots, with or without switch, ask me - I have
thousands of them!
remove NOT to Email me...
Geoff W
> Just use the 3 meg RA pots from the BF-era oscillator circuit. You can tweek
> the component parameters a bit, but it will work essentially the same.
>
> >Can anybody tell me where I can purchase 10 MEG and 4 MEG pots, I am
> >building a couple of tremolo circuits based on the early 60s Fender
> >circuits that used these values. ORiginally they seem to have used
> >reverse audio taper but I suspect I'd be dreaming to find these so
> >linear would have to do the job, if I can find them!
Just to get this straight, you're saying that I can replace a 10 MEG
RA pot in this circuit with a 3 MEG pot and tweak a few component
values? It seems a rather large change but I trust that you know what
you are talking about. Can you please advise me which component
values I will need to tweak to have the circuit operate correctly?
adam
elect...@dcsi.net.au (Geoff W) wrote:
Look on the aiken amplification website, in the tech section there is a
wonderful article on tremolo oscilators, it should help alot.
adam
Geoff W
Thanks alot guys, I'll check out the aiken site to get my head around
the possible substitutions.
nuke
Just compare the BF era tremolo oscillator to the brown era oscillator. The
first tube section is the oscillator, the second section is just an amplifier
to drive the signal, common cathode amp for the BF era, cathode follower in the
brown era circuit.
If you copy the BF circuit, you'll have the added advantage that the tremolo
effect will turn off when the foot pedal is unplugged. The only real difference
between them is the 3M RA vs. 4M RA
The scary one is the intensity control - but it isn't that bad. The brown's
cathode follower isn't going to be heavily loaded by the 3M RA pot, the cap
network just forms a low pass filter to keep any artifacts out of the LFO
signal before being passed to the harmonic modulator. (I'm assuming you are
doing the 6G8/6G8A Twin type tremolo).
I've had to do this while restoring a couple of brown era amps since the 10M RA
is just about impossible to source.
Just try the substitution and see if you have enough gain. Diddle the value of
the 470K down a bit, the 4.7M and the .1uf cap to tweek it. More than likely,
a slight tweek here and there will get you where you want to go.
>Just to get this straight, you're saying that I can replace a 10 MEG
>RA pot in this circuit with a 3 MEG pot and tweak a few component
>values? It seems a rather large change but I trust that you know what
>you are talking about. Can you please advise me which component
>values I will need to tweak to have the circuit operate correctly?
Geoff W
the logic you describe well now. I'll be using the 3M RA pots in both
positions with a little tweak hear and there, it should do the
business!
Geoff
Bill Sundt
Geoff W wrote:
You can get 5 MEG reverse audio tapers from Soldano, we've got plenty.