TS Type Hisses

[petemoore]

I'm trying to debug the hiss from a Stompbox Alexa, it's basically a TS.
 I'm using an LM386 as a voltage divider.
 I've swapped opamps, so it's not that.
 I put a .033uf cap across the diodes, and although this reduces the hiss and bass some, there is still a pretty 'high pressure hose' hiss sound happening.
 Any ideas on other areas to look for [the possible causes] getting teh hiss out and still having treble content left over?...like:
 Bad Cap or...
 ANY ideas beyond what I've tried ?

[MartyMart]

Have you tried increasing the 47pf cap on the feedback loop ?
100 - 120pf ...

Marty.

[petemoore]

Yes !
 But
 I had to go up to .oo33uf to signifigantly [and inadequately] reduce the hiss amount, which also reduced the treble content.
 I think there's something wrong with it, I'd remember if it was hissing like this....it wouldn't have 'passed'.

[MartyMart]

Sorry Pete. you had said that in your first post !!
I had a look at the schemo, and there's no big caps in the circuit path that could cause this....
I presume that you used Poly's anyway ?
So, perhaps the original voltage divider would be better/386 is the culprit
.. ??
The original has two 100uf's and the one over +9/ground will obviously
keep the power line nice and "clean"

Worth a try.... ?

Marty.

[petemoore]

Two resistors of equal value and a cap or two, clipped in there [with the 386 pulled out, is worth a try, I suspect it's something else, this is a good Idea and I'll try it.,first in the process of elimination.
 My buddy traded me for it, then lent it out...and was asking 'should I lend it' to which I answered "it's yours, but my Exp has been it's much easier to lend something than to get it back".
 It has reverse polarity protection, maybe somehow the 386 got 'spiked' or shorted somehow...oh, I replaced that dohh...
 Anyway that's as good a suggestion as any for something to start eliminating variables with.
 I'm quite certain it didn't hiss like that 'before'...something happened.