Imagine you're a fiddle player who primarily plays without effects, but would occasionally like to be able to play with them. What can you do?

One option is to put a pickup on the fiddle and run that into guitar pedals. This will work, but pickups generally sound much worse than clip-on mics like the ubiquitous AT PRO-35. Since you're mostly playing uneffected, you don't want to give that up.

Another option is to get a vocal effects processor. For example, I have a VoiceTone D1. These take balanced XLR from the mic, send balanced XLR to the board, and provide phantom power, so they make a lot of sense technically. Unfortunately, since they are designed for a vocal signal I've found they sound pretty crummy when applied to fiddle or mandolin.

A mixer should work here, but it seems like both overkill and a hack? Get a small mixer with phantom power, run the output of the mixer into a guitar pedal, run the output of the guitar pedal into another channel on the mixer. For example, with a cheap mixer like the Behringer Xenyx 502 you would:

• run the mic into channel one, which provides phantom power
• pan channel one hard right
• run the right main output into the guitar pedal
• run the guitar's pedal's output into channel 2 (left)
• set the 2/3 balance to hard left
• run the left main output (balanced) to the mixer

A slightly less cheap mixer (ex: the Soundcraft Notepad-5, which I have) lets you do this with a monitor channel instead of panning, but it's still not ideal.

You're also in a funny place impedance-wise, where the guitar pedal may be expecting a high impedance input or to be driving a high impedance output. If you need that you could add a reamper (ex) before the pedal and a DI (ex) after. I'm not sure whether this is something pedals tend to care about?

All of this seems like a mess to me. It seems like maybe a bunch of people would want a box with:

• XLR input with phantom power
• A good quality pre-amp with gain control
• High-impedance 1/4" output to the pedal
• High-impedance 1/4" input from the pedal
• XLR output
• Maybe a second dry-only XLR output

Does a box like this exist? Alternatively, are there pedals in the same form factor as the vocal effects processors, but that are designed for instruments?