Marantz 2325 restoration

[goldswimmerb]

Hey guys, I was just looking for some advice. I have recently aquired an unrestored marantz 2325 for fairly cheap.

I so far, intend to replace PSU caps, audio caps and bulbs, but this will be my first time working on something as beastly as this marantz, what other modifications or preemptive repairs are recommend on these?

I saw some things about diodes and transistors.

My past experience is just working with a Yamaha CR-620 that still catches fire (has a short I'm too lazy to deal with since I've got some nicer equipment) and a transistor replacement and recap on a pioneer SX-737.

Thanks!

 

[Steven Tate]

A good place to start would be the cap list posted in the AK Database. The Phono board definitely needs to have the 2SC458 transistors replaced ( see cap list). The 2325 is pretty modular, so relatively easy to work on - with the exception of a couple of small boards behind the front of the chassis. Take good pics before any disassembly, and always use a dim bulb tester when firing up for testing. Test after each board so that if you have problems, you know where to focus. There are several good restoration threads for the 2325, so use the search function to browse through them. I think Leestereo has a thread considered to be the standard. Good luck!

 

[OFrank]

I concur with Steve. The leestereo is the standard but there are other threads. When I did my 2325 restoration I researched all of them and put together a plan to tackle it board by board. Good luck. Again, as Steve said, test after you complete each board.

 

[catrafter]

This what I think a full restoration should include, YMMV.
Complete cleaning of the covers, face plate, knobs, meter faces, rear panel and as much of the chassis as possible without tearing the whole thing apart.
Polish face plate, dial 'glass', meter faces and knobs.
Clean and lube all the controls and switches, clean and lube the tuning mechanism, replace the tuner shock mounts.
Clean, polish and lube all the jacks.
Replace all the small electrolytic caps with 105 degree rated parts, small film caps are used in wherever possible in the audio signal path and in strategic locations for best sound quality and stability. Electrolytic capacitors are a water based technology with a limited life span, (~30 years).
Replace the main filter capacitors with good quality parts that match the size of the old ones as much as possible so that the original mounting hardware can be utilized.
Bypass the main filters with small film caps to improve transient response.
Replace any suppressor networks with AC rated types.
Replace the speaker protect relay.
Update and upgrade the phono preamp to the latest production standards including the replacement of any problematic 2SC458 transistors.
Clean all the heat sinks, install new mica insulators and thermal compound.
Remove any glue from the circuit boards, it can become corrosive with age.
Replace any out of spec, corroded or overheated components.
Install LED replacements for the meters, dial, pointer, stereo, Dolby and function indicators.
Replace the dial and meter vellum.
Align/adjust to meet or exceed factory specs. This would include a complete alignment of the AM/FM tuner, the MPX decoder and the Dolby processor, adjustment of the bias, offset and power supply voltage.
Run a complete performance test of all functions, power output, distortion, frequency response, etc.

Tom

 

[goldswimmerb]

This what I think a full restoration should include, YMMV.
Complete cleaning of the covers, face plate, knobs, meter faces, rear panel and as much of the chassis as possible without tearing the whole thing apart.
Polish face plate, dial 'glass', meter faces and knobs.
Clean and lube all the controls and switches, clean and lube the tuning mechanism, replace the tuner shock mounts.
Clean, polish and lube all the jacks.
Replace all the small electrolytic caps with 105 degree rated parts, small film caps are used in wherever possible in the audio signal path and in strategic locations for best sound quality and stability. Electrolytic capacitors are a water based technology with a limited life span, (~30 years).
Replace the main filter capacitors with good quality parts that match the size of the old ones as much as possible so that the original mounting hardware can be utilized.
Bypass the main filters with small film caps to improve transient response.
Replace any suppressor networks with AC rated types.
Replace the speaker protect relay.
Update and upgrade the phono preamp to the latest production standards including the replacement of any problematic 2SC458 transistors.
Clean all the heat sinks, install new mica insulators and thermal compound.
Remove any glue from the circuit boards, it can become corrosive with age.
Replace any out of spec, corroded or overheated components.
Install LED replacements for the meters, dial, pointer, stereo, Dolby and function indicators.
Replace the dial and meter vellum.
Align/adjust to meet or exceed factory specs. This would include a complete alignment of the AM/FM tuner, the MPX decoder and the Dolby processor, adjustment of the bias, offset and power supply voltage.
Run a complete performance test of all functions, power output, distortion, frequency response, etc.

Tom

Wow thanks for all that! This will be my first full on restoration. Wish me luck lol.

I'm usually a firm believer of not swapping caps unless something is visibly or audibly wrong, but with something this high power I want to take every precaution possible for the best possible results.