Switchable TS to SD-1 Mod?

[Paul Marossy]

The SD-1 and TS-9 (and 808) are the same circuit with the main difference (design wise) being the asymmetrical versus symmetrical clipping.  There's almost 20 part differences (value wise) between the two.  I went through and changed my SD-1 to TS-808 specs and it sounds WAY different now.

Hmm... cheap way to get a TS clone with a nice enclosure? 

[StickMan]

Bingo!

[vanhansen]

The SD-1 and TS-9 (and 808) are the same circuit with the main difference (design wise) being the asymmetrical versus symmetrical clipping.  There's almost 20 part differences (value wise) between the two.  I went through and changed my SD-1 to TS-808 specs and it sounds WAY different now.

Hmm... cheap way to get a TS clone with a nice enclosure? 

Yup.  I learned a lot along the way just doing that too.  Add a switch that'll switch in and out D6 to go between symmetrical and asymmetrical clipping.  You can also add in a bass boost switch -  C3, go from 0.047uf to 0.1uf.  That is really the only cap that needs to be changed to increase the bass.  Increasing too many others turns it in to mud.

Once I got done with it, I was A/Bing it against my bandmate's real 808 and it sounds REALLY close to it.  Mine still has asymmetrical clipping and I know that is making a big diff.  I'm probably going to add a toggle in for that one.  I didn't mess with the tone control section either.

[Paul Marossy]

Cool, thanks for the info guys! 

[vanhansen]

No prob, Paul.  Check the SD-1 Mods page on my site.  It's all documented there.