This cosmetically near perfect Baby Marantz came to me for a full restoration earlier this year, it was built in 1973.
At some point in it's life, it had been dropped hard on it's feet, bending the supports.
After a full evaluation which included testing every function, AM/FM performance, distortion, power output etc., the client was provided with a detailed, firm estimate.
Once the client approved the estimate, the knobs and face plate were removed and stored carefully to avoid any dings or scratches.
Since the proper operation of so much of the receiver depends on the low voltage power supply, I started there. All assembly glue (which can become hygroscopic with age) was removed,
the overheated current limiting resistor, under rated voltage regulator transistor and all electrolytic capacitors were replaced, then the supply was tested.
Next, the phono preamp was rebuilt, new electrolytic capacitors with film types in the audio signal path for best sound quality and stability.
The tone board was rebuilt, new electrolytic capacitors film types in the audio signal path for best sound quality and stability.
I also cleaned all the controls and switches at this point as they are easily accessable.
The tuning mechanism was cleaned and lubricated, the dial cord was tightened so it didn't slip anymore.
All electrolytic capacitors on the tuner board were replaced. I used film types in the FM audio signal path and in a few selected locations for best sound quality and stability.
The heat sink and output transistors got cleaned, new thermal compound was applied.
The power amp was rebuilt, new electrolytic capacitors with film input coupling types. The output coupling capacitors were increased in value for better low frequency response.
The main power supply filter capacitor was replaced with one having the same diameter so that the original mounting hardware could be utilized.
It was also bypassed with a film type for better transient response such as cymbal crashes in the music.
The dial and meter were polished, new non-yellowing vellum and all LED lighting was installed
The final aligments and adjustments were then performed. This included a complete AM/FM alignment, power amp idle current and DC offset.
All functions were tested to assure that it meets or exceeds the manufacturer's specifications.
Finally, the face plate and knobs were cleaned and polished, then reinstalled.
I really had fun restoring this little guy and enjoyed listening to it even more!! Thanks for looking.