Boss DM-2W bypass mod

[beatnik]

Hello everyone,

I am working on a little project, a pair of the newer Boss DM-2W analog delays housed into a rack mounted unit, for true stereo delay.

I need some help figuring out how to modify the bypass circuitry, so that the pedal is always on.

The circuit is all smd components, not so easy to trace the schematic, was wondering if anybody has some tips to get me started.

I presume there is a FET somewhere responsible for switching, that I can just bridge together, but I have never really worked on a Boss bypass circuit and the smd components don't really make easy figuring out what's going on.

Any help is highly appreciated

[garcho]

Might be hard without some idea of the scheme. Can you take a few pictures of the PCB? Is it still their flip-flop bistable multivibrator FET switching? I might be wrong but it might just be hooking up the JFET gates together (on the cathode side of the diode, not the actual gate). You could also jump the FET and do true bypass if you want, more work and soldering, though. The more information you provide, the better and quicker your help will be.

[Rob Strand]

The easiest way would be to find the flip-flop for the footswitch then just  force one of the transistors to be held in the on- state (or off-state). The flip-flop is a standard circuit in boss pedals.  You start at the footswitch wire then find the two caps that connect together and fork off to the each flip-flip transistor.   If you short the base-emitter of one of the transistors it will force the flip-flop to be in one state.  If you get the wrong transistor just try shorting the base-emitter of the other flip-flop transistor.
[You could also short the emitter collector, that might actually be preferable.]

If you want to start bridging JFETs then you will have to trace a lot more circuit.  Also there could be many JFETs spread over the circuit (I haven't checked the schem).   For effect mode some will be off and some will be on so you need to lift some and bridge others.    Forcing the flip-flip does it all for you from the one place.

[11-90-an]

position on/off switch to on, snip-snip switch-to-board wires?