Turns out I soldered the components that are supposed to be on the
output of the preamp onto the first set of inputs by mistake. I now
have two options (neither of which am I prepared to do tonight). I can
either just reverse the first set of inputs and the output jacks, or I
can disassemble the thing and put it together properly. Either way is
going to be a pain in the ass, and I’ll probably need some replacement
capacitors and resitors, which I don;t have right now….