Numbered Boss SD-1 Schematic

[phillip]

Here's the newest version of my Boss SD-1 Super Overdrive schematic.   I've gone back and added the corresponding part numbers that appear on the circuit board to make referencing easier.

http://axiseffects.home.att.net/misc/SD1.gif

Phillip

[petemoore]

At the bottom there are those little caps around the X arrangement...I've seen these X's before...looks like tone shaping.
 I'm assuming some of the parts are for the bypass switching.
 Boss seems to opt for high  parts count units.
 Thanks Philip...looks good !!!

[phillip]

All the stuff toward the bottom of the schematic, including that "X" arrangement of the resistors and capacitors, is part of the flip-flop circuit that activates the JFETs for the electronic bypass switching.

I can see the benefits of the JFET switching, being that there is no noise whatsoever when the effect is switched on and off, and the signal is also passing through a pair of buffers when the effect is on or off.  The down side is that the buffers on the input and output, as well as the flip-flop circuit, need to be powered to operate...so as long as the battery doesn't die the FET switching is a great option!

Phillip

[newfish]

If anyone has this, could they please re-post / PM me?

My 'mods' have not been quite so succussful... 

Thanks.

[newfish]

Ah.

Further Googling gave me this, if it helps anyone else...

http://www.hobby-hour.com/electronics/s/sd1-super-overdrive.php

Cheers!