This Fisher x200c was brought in unused for several decades along with the FM100c Tuner which it was mated to. Both units have a great vintage patina to them but had major operational issues. We used a can capacitor kit from Hayseed Hamfest to rebuild the power supply of the amp, and replaced all signal chain coupling capacitors with Illinois Capacitor MXP series poly caps. The amplifier has a fixed adjustable bias potentiometer added to the circuit for bias adjustment. The tuner had it’s power supply rebuilt and works well pulling in distant stations. There is no multiplexer in the tuner but it is a really cool partner to the amp. Happy to answer any questions, and this is eligible to be combined with a Klipsch Heritage speaker setup to make an amazing vintage/modern system.