The Boss RX-100 is an analog mono spring reverb. Personally, I think it has a really nice sound, more lo-fi than the Great British spring reverb from my previous post, but that also gives it a bit more character. It has two inputs: A (mono jack) for microphones and instruments, and B (stereo RCA) for line-level devices.
Since I mainly want to use it as an aux send, I want the reverb to output only a wet reverb signal without the dry signal. To achieve this without the mod you had to set it up as followed:
Input signal to the rear (“B”) RCA
Output signal to the front (“A”) jack.
Then you can pull the B volume knob, and you’ll have a wet-only signal.
I found that a bit inconvenient since I also want to switch to a mixed signal from time to time. The preamp stage of input A can actually sound great if you overdrive it a bit in combination with the reverb. I’m also personally more of a fan of jack connectors than RCA connectors.
To cut off the direct signal from input A, simply lift one leg of resistor R31. Since I wanted to switch between wet and dry/wet, I really only needed an SPST toggle switch that can only switch to an ON or OFF position.
I wired the switch in series, soldered the resistor to the wire, and covered it with heat shrink tubing.
The switch fit nicely on the back of the unit.
Simple and effective.
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