Need to identify this 3-pin Connector to a small amp. It's a Pre-Amp input
Looking at the notches in your less than clear picture it appears to be a JST B3B-XH-A(LF)(SN). 

You just need to verify pitch in this Datasheet., however they seem to match with what you have given.

For a mate you would be looking at XHP-3



Digi-Key offers a variety of jumper wires or contacts for that housing depending on the wire gauge you need. Here is a list of options. https://www.digikey.com/short/z3fv52