replacing a generic tone control in an old tube amp...

[marrstians]

hey... i have an old tube amp... more like old stereo setup, ac line run stright to the first tube, no dc tranny... anyways... it has a volume and tone control but it doesn't do much... it's set up like a guitars knobs.. one wire going into the volume pot with one lug grounded to kill the volume and a .01 cap connecting the middle lugs of both pots with one of the tone knobs lugs grounded... so pretty much all it does is kill a little highs but that's it... basically useless... is there a better way to wire it up, maybe a more responsive filter than a .01 to ground...?

[Lonestarjohnny]

I got 2 amps like that and i gotta do the same thing, the variation of the pot leaves a lot to be desired, I may do a Fender style on 1 and maybe a Marshall style on the other.
JD

[Ballz]

Guys, these things can (and will!) kill you - pleeease make sure that you always use an isolation transformer between the amp and the wall voltage....
Over here (Sweden), this "design" has been strictly illegal since the 1950:s due to the many people that were toasted by radios without a proper power supply.

I can´t believe this stuff is still out there. Please be careful.

Cheers

/Richard

[Lonestarjohnny]

there is a lot of this stuff still around at the flea/markets, I just picked up a small practice amp, look's brand new, probably early 60ish, maybe older, i have'nt had a chance to date the speakers or pot's yet, it is very different in the tube selection, some #'s i've never seen, they operate off ac voltage though, no d.c., first time i've ever seen this in a guitar amp, has to be a very dangerous critter though, still very interesting to look at and ponder why somebody would do a circuit like this.
just always remember, no Tranny=high shock risk.
play one barefoot on a concrete floor and it might be your last Waltz !
JD

[Paul Marossy]

You could try any one of these tone stacks, if you can stand some insertion loss:

http://amps.zugster.net/articles/tonestacks/index.html

I hear that the Baxandall tone stack is really cool. I have yet to try one of these, though.