that tone control...

[federico]

Hi All,

After building some ts-808 clones , i've found tone control working badly.
I've used 22kohm linear pot. (the commercial value here)
In all finished circuits, problem is the same : tone controls is functional only in the first and last fifth of its rotation, while middle 3/5 of rotation give no change in tone.

Any idea
Is there a special tapered pot. on original units

Thank you very much.

P.S. Overall overdrive performance is good, but cuts dramatically high and low ends of clear crystal sound of my strat into my super reverb.
Any suggested mod ??

Thank you very much !!!

[cd]

Yes, there is a special taper on the originals... no, you can't simulate it with resistors, it's not log/anti-log taper, or anti-log/log taper (which looks like a tan x curve), it's more of a flattened "S" shape.  No, I don't know where to get any pots of that taper, though if you send a few emails to Smallbear, that may encourage them to get some custom ones made for us all.

As for cutting the highs and lows - that's what a Tubescreamer does.  Cut lows to prevent flabby distortion, cut highs for a smooth OD, overall result, a midrange emphasis.  It is what is it.  If you don't like the Tubescreamer sound, I'd suggest using something else.  Can you EQ it out with a graphic EQ after the TS (pump up the bass and highs) - yes, but to my ear again it sounds shrill and muddy, not what a Tubescreamer is supposed to be.

[davebungo]

We use a special 'S' taper in some of the equipment we produce at work, I'll see if I can find the supplier but I think it's a 250K so may not be much use.

[federico]

In fact...
Original ts808 uses an ALPS 20K "W" tapered potentiometer, as you can see at http://tubescreamer.digiteltlc.com
I've taken some pictures, look at number seven.....
Also there are tapering specifications by ALPS and a graphic i've drawn after tone pot measurement.
Hope it helps somebody (like me) in understanding that control....

To Davebungo : Yes just the supplier or manufacturer is enough

Thank you