tonepad Sinamp Volume issue

Started by maiko, March 13, 2017, 04:18:02 AM

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maiko

so ive built the sansamp gt2 from tonepad and actually this is the 2nd one

This time im planning to use it as a preamp for my ggg TDA20x0

Question it is a very loud pedal i hardly past 8oclock on the volume and its already too loud.

any suggestion on how to lower the output.   it has a 5088 just before outpud.  can i adjust it there

any help would be appreciated.

https://imgv2-2-f.scribdassets.com/img/document/194292535/original/3894fea7ec/1487265476

duck_arse

try swapping the "vol" pot B100k with a log pot A100k. that might help shift the too loud point higher.
don't make me draw another line.

maiko

Yup ive tried this it actually helped alot and it placed my useable point to halfway but beyond
that its loud!! hahaha

antonis

Place a resistor in series with pot's upper lug..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

maiko

you mean across lugs 1 and 2

so your suggesting i lower the pot value?    by half? so if 100k i solder also a 100k across 1 and 2?

duck_arse

not across, in-line with. try half the value of the pot, in series with the hot lug, so full volume will now be 33% lower.

really, you put a knob on that control, what difference does it make where you turn it to for comfortable listening levels?
don't make me draw another line.

maiko

ok i try to solder a 50k in series to lug 2

antonis

#7
Hot lug!!! - Upper lug!!! - Lug No 3!!! - The one that has the higher voltage!!!  :icon_cool:

Lug 2 goes to Op-Amp non-inerting input and the addition of 50k resistor will low down the GAIN of the NFB loop..  :icon_wink:
(and also the HPF cut-off frequency..)
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

maiko