This second Mp-4 mixer I got in wasn’t as filthy as the first one which made the cleaning easier. It went petty smooth for the most part. I replaced the capacitors and troubleshot and replaced some noisy transistors. I cleaned the pcb up when it was all said and done. I used some aluminum flashing to make a new reflector for the knob that was missing it. It is very common on these old ace tone knobs. A few fell off during cleaning. I had to glue them back on and repaint the pointer lines with some lacquer.
Guitar-Restos 