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DIY Stompboxes => Building your own stompbox => Topic started by: Beo on March 29, 2012, 04:21:47 PM

Title: tube screamer gain recovery
Post by: Beo on March 29, 2012, 04:21:47 PM
Searched and read, but answer not quite clear to me yet. Can volume differences from different clipping diodes arrangements (e.g. SI / GE diode switch) be balanced using gain control on the tone half of the opamp? E.g. switch in a different feedback resistance for more gain with GE clippers. Or is it better to use the output buffer transistor as gain recovery?
Title: Re: tube screamer gain recovery
Post by: kurtlives on March 29, 2012, 04:29:23 PM
Ya sure you can change the feedback resistor up or down to compensate for the volume difference in using different clipping diodes.
That's easy to do as you just have a switch that is simultaneously changing the feedback resistor as you change the diodes.

The issue with this is that as you change the feedback resistor (and therefore gain) of that stage you are also changing the frequency response.
Title: Re: tube screamer gain recovery
Post by: Beo on March 29, 2012, 04:37:58 PM
Quote from: kurtlives on March 29, 2012, 04:29:23 PM
The issue with this is that as you change the feedback resistor (and therefore gain) of that stage you are also changing the frequency response.

That's part of what I was wondering. The change in gain will not need to be that much to balance level, so the effect on frequency response might not be that drastic. This would have to be usable across the tone control range though. I'm going to experiment with this on breadboard. I was hoping not to have to leave the output buffer in the circuit in order to achieve a bit of gain recovery.
Title: Re: tube screamer gain recovery
Post by: lowvolt on March 31, 2012, 06:17:24 AM
I dunno .. I kinda like the way different clippers change the output level .. not only does it sound a bit diiferent but the different levels also *hit* the amp in different ways producing different amplifier response ... kindof makes it a "sister circuit" to amplifier rather than just a distortion pedal.  Maybe sister circuit is a bad way to look at it .. perhaps like a pre-preamp.  Er .. um .. yeea.  Wow .. the stuff that comes out of my mouth sometimes!  Haahaa!

::)