Boss bypass flaw... any real fixes?

[tjburton]

Can somebody shine some light on why some boss pedals (SD1) have issues in the bypass mode. The issue I am refering to is a "bleed" of the effect when in the bypass mode. I've heard this is common (and I have one that is very noticable). The easy solution to this issue is to put another pedal that has a buffer before the SD1 to solve the problem.

Aside from putting the SD1 in a true bypass loop or having to use another pedal to send a buffered singnal into the SD1, is there anything I can do to improve the quality of the bypass in my boss pedal??

Thanks guys,
Tim

[Hal]

you can do a true bypass mod on the pedal...

_some_ posted a bunch of pictures a while back about how to do that, with a blue 3pdt.

there are _tons_ of mods available for SD-1's.  I dunno if any improve the bypass...

[mikeb]

The FET switching might not be turning all the way 'off' - if so, it can be fixed and isn't inherent to the nature of the pedal. I think there's more info in the archives here.

Mike

[Boofhead]

A way to reduce the problem was to replace the 22k's R11 and R14 (which are near the switching JFETS) with shorts.  If you compare the SD1 and TS9 (which suffers less from this problem) you will see the difference is the extra 22k's on the SD1.

Beyond that you can only change the JFETs.

Here's the original thread,

http://diystompboxes.com/sboxforum/viewtopic.php?t=11742