Maxon - SD-9 Sonic Distortion [schematic]

[culturejam]

Schematic Heaven has the SD-9 schematic listed as being the GGG "Sonic Distortion" schem. Is this accurate?

I did a search here for "SD-9" and found that it was listed as a TS808 derivative, but to my very newbish eyes, it looks closer to a Dist+ or Rat than to a Tubescreamer. If the "Sonic Distortion" really is the SD-9 schem, then it appears to me that only half of the dual op amp is being used, and the clippers go to ground rather than feed back into the op amp.

Am I reading this correctly, or have I misunderstood something?

Thanks

[Dirk_Hendrik]

As far as I can remember that schematic shows the essence of the SD9 only. Bypass and other not directly related stuff omitted. As for the clipping et al you are completely correct that a SD9 is in the Dist+ school and not in the TS style. Calling an SD9 a TS derived circuit is nonsense.

[culturejam]

Thanks, Dirk. I'm glad that I wasn't totally misunderstanding the schematics.

The thread I mentioned where the SD-9 is classified as an 808 derivative is here:
viewtopic.php?f=1&t=1536

[analogguru]

If you look at this (unverified) schematic:
http://www.aronnelson.com/gallery/main. ... 9.jpg.html
you will see that the second half is used as a buffer for the clean signal.
This is on the real pcb-layout the same.

analogguru

[culturejam]

Thanks, AG!

Wow, the schem you linked doesn't look all that much like the one at GGG.

[ubersam]

...I did a search here for "SD-9" and found that it was listed as a TS808 derivative, but to my very newbish eyes, it looks closer to a Dist+ or Rat than to a Tubescreamer...

It is the OD-9 that is supposedly the Tube Screamer ckt, but true-bypass instead of JFET bypass, at least the later ones are.

[ChrisB]

Found another schematic.
http://www.geocities.com/SunsetStrip/Vi ... _schem.gif

Great sounding pedal.

[Dirk_Hendrik]

OK another shot. The tone control section in the schemmo from Aron's page is wrong for sure.

http://www.dirk-hendrik.com/ibanez_sonic_distortion.pdf