This is a funny little solid state amp I bought from a fellow on Craig’s List. I bought it “as-is” and it hummed and made noise but passed no signal. At first I thought it was Japanese, but when I took off the back panel there was a tiny schematic marked “Paris Corp. Salina, Kansas”! I replaced the first transistor which took care of the noise and lack of signal, but the tremolo wasn’t working. I rebuilt that section with some new caps and a resistor and dug up a vintage footswitch to turn it on and off. The power supply filter cap had already been replaced so I can only think that the amp has always had some hum (it was certainly not high-end when new). Adding a second stage of filtering killed the hum and made this into something that could actually be used. Honestly it was more work than the amp is probably worth, but a fun project nonetheless!