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DIY Stompboxes => Building your own stompbox => Topic started by: tman on June 04, 2004, 06:55:46 PM

Title: Boss SD-1 to Tubescreamer
Post by: tman on June 04, 2004, 06:55:46 PM
Hey I have just been looking at the schematics on the web of the tubescreamer. The one difference I have noticed is that from the clipping diodes and the inverting input on the opamp is that the .047 cap and 4K7 resistor goes through a 100K resistor back into the inverting input also it is tied to 4.5v

However on the Tubescreamer this just goes to ground what is the better option ?
Title: Re: Boss SD-1 to Tubescreamer
Post by: cd on June 04, 2004, 07:07:50 PM
Quote from: tmanHey I have just been looking at the schematics on the web of the tubescreamer. The one difference I have noticed is that from the clipping diodes and the inverting input on the opamp is that the .047 cap and 4K7 resistor goes through a 100K resistor back into the inverting input also it is tied to 4.5v

However on the Tubescreamer this just goes to ground what is the better option ?

On the TS-9 there should be a 10k resistor.  Either way it should make no difference sonically.
Title: Cheer
Post by: tman on June 04, 2004, 08:35:49 PM
What do you think will help my sd-1 sound a bit fatter it sounds quite thin sounding.
Title: Re: Cheer
Post by: cd on June 04, 2004, 08:53:15 PM
Quote from: tmanWhat do you think will help my sd-1 sound a bit fatter it sounds quite thin sounding.

1) read "Technology of the Tube Screamer" at www.geofex.com, it has everything you need to know there, or
2) change the input cap to .1uf from .022uf
3) change cap in feedback loop to .1uf from .047uf (the one connected to the 4.7k resistor)

Experiment with different cap values, once you increase the bass you'll probably find the distortion is muddy.  That's just how the circuit is.