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DIY Stompboxes => Building your own stompbox => Topic started by: james on April 08, 2004, 01:13:21 PM

Title: Boss SD-1 mod
Post by: james on April 08, 2004, 01:13:21 PM
Hi,

I'd like to try symmetrical clipping in my Boss Super Overdrive. (New)
Do I just remove one of the diodes, and use a jumper in its place?
Any help, or suggestions will be appreciated. Thanks.

James
Title: Symmetrical
Post by: petemoore on April 08, 2004, 01:20:44 PM
That would be same same diode configs
 say two 1n914s seriesed, going>way and two more seriesed 1n914's going<way
 or...two 'anti'parallel same type Si diodes antiparrallel and leads connected
 -->l
 l<--
 Hopefully my art didn't get folded upon entry!!!
Title: Boss SD-1 mod
Post by: phillip on April 08, 2004, 01:25:16 PM
In the SD-1, you can replace either D5 or D6 (but only one of the two!) with a jumper and it will be symmetrical.

Check out my SD-1 modification article at my site.  I don't do the symmetrical mod, but I do have a complete schematic that's fully numbered according to the Boss circuit board (the link to the schematic is in the text):

http://fuzzcentral.tripod.com/SD1.html

Personally, I find the Boss asymmetrical clipping to be much more sonically pleasing ;)

Phillip
Title: tack on a switch...
Post by: petemoore on April 08, 2004, 01:41:24 PM
A spst wired across the one diode to make a switchable jumper...
Title: Boss SD-1 mod
Post by: phillip on April 08, 2004, 01:51:38 PM
Even better ;)  Analog Mike uses a push-pull pot for the asymmetrical/symmetrical mod, but I think his may be specially made for the SD-1...I haven't found any push-pull 16mm pots that have the split-knurled shafts in the right value or taper...  Either that or he uses a solid-shaft pot with a taper that isn't quite the same, and uses one of the set screw-type knobs that are otherwise identical to the ones that Boss uses.  The Boss knobs are press-fit, so using those with a push-pull pot may not work too well ;)

Phillip
Title: Boss SD-1 mod
Post by: james on April 12, 2004, 03:32:17 AM
Thank you for your replies, and for your help. Your suggestions were
great.

James