Boss sd-2 dual overdrive

[spad91]

Hi,

I have owned one of these and it is definitely one I cannot part from...
OK... To be perfectly honest, I have half a dozen in my drawers, most still being originals, a couple being slightly tweaked, and one being completely apart as I tried to change all the capacitors in the signal path, but ended up messing the PCB...

The first channel sounds a little harsh to my ears, as I use rather bright amps, but I reckon it could be a good one for people using darker (solid state...?) amps, as it sounds very natural, basically an overdriven sound without any frequency being pushed or scooped.

The lead channel, if you ask me, is definitely worth isolating and building as a standalone distortion. Yes, the name of the pedal is 'overdrive', but the second channel is definitely on steroids...

Here's a link to a demo thet I feel reflects what I have felt myself with this pedal in my rig:
Demo by Cameron Johnson
and Cameron's comments, that I completely agree with:
The SD-2 takes the multi mode concept of the Turbo Distortion and Turbo Overdrive, and uses concentric knobs to let you control everything in each mode. That's a huge plus! This pedal basically has two complete separate channels, which is very cool for such a small pedal.

The Crunch mode isn't really anything to write home about. In my opinion, you really need to crank up the drive and level to make it work. It's just somewhat bland and sounds better in front of a dirty amp.

The lead mode is another story. It sounds great in front of both a clean and dirty amp. One of the best Boss drives I've tried. I will say that unlike most Boss drives, you would want to run the tone at about 3 o'clock. I find the 12 o'clock position to be a little dark.

Overall, the SD-2 is a winner in my book. If it were in my rig, I probably wouldn't bother with the crunch mode, and just leave it in the lead mode.

Here's a link to the schematics:
Boss SD-2 Schematics

2 1/2 ICs, I know... But maybe this could be a challenge more than a dead end...?

Cheers

Fred

[Frank_NH]

Thanks for the schematic.  This looks very doable.  You could easily isolate each channel (crunch and lead) without the buffers on a separate veros.  As you mentioned, the crunch channel is somewhat blah, but you could increase the gain by upping the gain pot from 250K to 500K or 1M.  The lead channel, however, is very interesting - 5 op amp stages with gradual gain and tone shaping.  I'd love to try this one.

Over to you IvIark and/or Mirosol...

[spad91]

Come on, you vero designers out there! It's the rainy season again, and I am giving you an opportunity to keep away from boredom...