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DIY Stompboxes => Building your own stompbox => Topic started by: Canis guitarus on December 31, 2009, 03:07:11 AM

Title: Input Signal Attenuation - whats the best way?
Post by: Canis guitarus on December 31, 2009, 03:07:11 AM
Hello there,

This is my first post here - so be nice eh! I searched your forums/FAQ for an answer on this and couldn't find anything obvious. So here goes ...

I have completed my first pedal (the Tweak - O off the Small Bear site) and I have been madly tweaking the circuit to figure out how things work and try get it to sound how I want it. I have found that the full volume signal from my guitars (HB's and SC's) seriously overdrive the transistor (PN100 in my build). Its easy enough to fix by adjusting the guitar volume but this is a pain when you are playing (you know - stomp, fiddle fiddle - now where was I?) so I figure I need an attenuator for the input signal. Is there a standard method for doing this? Or is there a better place in the circuit to achieve this?

Great site by the way.

P.S. Cant seem to upload the schematic - sorry team.
Title: Re: Input Signal Attenuation - whats the best way?
Post by: Kearns892 on December 31, 2009, 11:56:51 AM
I suppose you could attenuate the signal by adding a simple volume control at the very beginning of the circuit. Wire a potentiometer with  lug 1 going to the input lug 2 moving forward to the rest of the circuit and lug 3 going to ground. I've never done this but you should be able to try it with just some alligator clips.
Title: Re: Input Signal Attenuation - whats the best way?
Post by: JKowalski on December 31, 2009, 01:38:17 PM
Quote from: Kearns892 on December 31, 2009, 11:56:51 AM
I suppose you could attenuate the signal by adding a simple volume control at the very beginning of the circuit. Wire a potentiometer with  lug 1 going to the input lug 2 moving forward to the rest of the circuit and lug 3 going to ground. I've never done this but you should be able to try it with just some alligator clips.

Or just two resistors wired up as a voltage divider (same thing, just not adjustable). If you EVER need simple attenuation, that's your ticket - voltage divider.

If you want it buffered as well, you could make a op amp stage with a gain of less than one but its really not necessary in most cases.
Title: Re: Input Signal Attenuation - whats the best way?
Post by: Paul Marossy on December 31, 2009, 03:59:25 PM
Quote from: JKowalski on December 31, 2009, 01:38:17 PM
Or just two resistors wired up as a voltage divider (same thing, just not adjustable). If you EVER need simple attenuation, that's your ticket - voltage divider.

If you want it buffered as well, you could make a op amp stage with a gain of less than one but its really not necessary in most cases.

+1