reducing gain in ds1

[drk]

Hello all!
i got a ds1 but i think it has too much distortion(at least for the stuff i used it), and i've read in the wiki(or in the faq, dont remember) that to reduce gain, you just needed to add diodes to the existing ones. so, my question is i add diodes to which diodes in the ds1? do i need to add to all of them?
please help, still begining
thanks

[the_random_hero]

Change the diodes to LED's - sounds awesome. Look up the Keeley mods, these incorporate a diode change as well as some well needed cap/resistor changes.

[brett]

Hi
LEDs are known for adding "crunch", so I don't think you'll get the effect you want by changing to LEDs, or any other change in the diodes.

Instead, you need to increase feedback around the op-amp (the trinagle in the schematic).  To increase feedback at high frequencies, increase the size of the feedback cap (it's a 51pF in the tubescreamer and DS-1, I think).  About 220pF will do the job.

Also, to reduce gain across all frequencies, lower the size of the resistor that's in series with the gain pot (it's a 51k, I think). 10 to 22k would be good 10k lowers minimum gain from 10 to 2, and 22 lowers it from 10 to 5.
cheers

[drk]

thanks, i've tryed adding a couple of diodes and it did made some change, its softer, but gonna try those too!
thanks 

[MetalGod]

Hello all!
i got a ds1 but i think it has too much distortion(at least for the stuff i used it), and i've read in the wiki(or in the faq, dont remember) that to reduce gain, you just needed to add diodes to the existing ones. so, my question is i add diodes to which diodes in the ds1? do i need to add to all of them?
please help, still begining
thanks

If you look at Q2 it's setup as a gain stage (not an emitter follower like Q1).  The emitter resistor on Q2 (R9, 22ohms) could be raised to lower the distortion from that stage - try 1k.

I would also try upping R13 (4k7) - try 10k

Taking the clipping diodes out altogether doesn't really reduce the gain that much (imo), it's still pretty dirty - it IS designed to distort the signal afterall.

As 'the_random_hero' pointed out, you could play with the resistor in series with the gain pot (R11), it's 100k stock.  Try halfing the value to 47k.

I'd try them one at a time to judge the effect each has.