So, I decided to tackle the Dimension C (!) and am about halfway through the design process for a project that I will release to the community in a couple months. It's going to be in a 125-B and no SMD. It's been a fun challenge and I've got a solid plan to make it all fit..
Now I'm getting to the point where I have to decide which bypass scheme to use. I was originally just going to use the Boss bypass—the DC-2 uses op-amps for the buffers, so as long as you use good-quality op-amps, the bypass should sound great. However, I just found out that the original Boss bypass doesn't work well with the mechanical momentary switches I was planning on designing around - it's made for a tactile switch that has much less bounce, and the circuit can be unreliable when using something other than a tactile. So that's a no-go.
This pedal is a mono->stereo splitter, so traditional true bypass isn't in the cards. It's got to at least pass through the first op-amp buffer stage to cleanly split the signal. I've seen others do senseless things in the name of true bypass (IIRC the Fromel Seraph would actually cut out the 2nd channel when in bypass mode... what?) and I want to make sure this is done right. Just looking for some opinions and feedback on what is the "rightest"
Original schematic here. The two circuit options, as I see it:
1) Preserve the original bypass path, meaning it goes through the input buffer, then pre-emphasis, de-emphasis, and out. Requires the equivalent of three SPST switches, plus LED.
2) Hard-wire the circuit "on" (omit & jumper Q1, Q11, Q12). Split the signal immediately after the input buffer. One pole of the switch grounds the circuit input from that point, and two poles switch the outputs, each going through an output cap. Still requires the equivalent of three switch poles not including LED, but this time they have to be double-throw.
Then there's also the actual technology of the bypass:
1)
Mictester's latching relay, using a latching SPST switch and using two DPDT relays in parallel. One of the four relay switches will be unused. The relays are $3 each, but the other parts are pennies.
2) Optical bypass (H11F1/Optotron method), but with a 3PDT stomp switch instead of the usual DPDT. The one downside here is that the post-buffer input would not be grounded in bypass, just blocked by the optoFET, but that's probably fine.
3) 4PDT switch. (I really, really, really don't want to do this because of the inconvenience of sourcing them and the potential for hardware failure, but it's an option.)
I think either circuit scheme will work with any of the three bypass methods, so any combination of the above is an option. Whichever method I decide on will have to be built into the circuit and will be pretty much required, so that's why I'm trying to get some feedback before going full steam ahead on one specific method. What do you guys think? If you were building it, what would be your preference and why?