Say hello to my new (old) Marantz 1250. The sound out of it lacks any dynamics, so I figure it needs a recap. I've received some advice from AudioKarma to replace all the tantalum caps along with the electrolytic caps. Any suggestions on capacitor choice, brand or otherwise would be greatly appreciated.
I'll be updating this thread as work progresses. For the last few months this amp has been sitting in my living room with dryer sheets inside it to get rid of the musty smell. There's a little bit of rust in the unit that I'll be sanding out and repainting as well. I'll post a full teardown along with component order from digikey when I can.
I'll be updating this thread as work progresses. For the last few months this amp has been sitting in my living room with dryer sheets inside it to get rid of the musty smell. There's a little bit of rust in the unit that I'll be sanding out and repainting as well. I'll post a full teardown along with component order from digikey when I can.
amp pron would be much appretiated 😉😉
generally Nichicon or Panasonic caps would be best choice, also I would change any 'small' value electrolytics with film caps of same value....
oh, and, guys over at AK know their shiet so I wouldn't hesitate to take their advices 👍😉
generally Nichicon or Panasonic caps would be best choice, also I would change any 'small' value electrolytics with film caps of same value....
oh, and, guys over at AK know their shiet so I wouldn't hesitate to take their advices 👍😉
Aye, amp pr0n incoming then 🙂 Could you please define a guideline on what a "small" value electrolytic would be?
Quite partial to CDE for the large caps, Panasonic FR for the middle sized power caps with AZA as an option for preamp power supply.
I’d get hold of a schematic or trace out the board to make one. It will make it easier to look at what purpose the caps are for.
Will be interesting to see film caps in there too.. will keep an eye out for updates.
You say it has been in a moist atmosphere - check any carbon comp resistor values too. They can absorb moisture and over time can drift in value (replace with what you want) but it may be why things are also operating out of spec.
I’d get hold of a schematic or trace out the board to make one. It will make it easier to look at what purpose the caps are for.
Will be interesting to see film caps in there too.. will keep an eye out for updates.
You say it has been in a moist atmosphere - check any carbon comp resistor values too. They can absorb moisture and over time can drift in value (replace with what you want) but it may be why things are also operating out of spec.
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The first "culprits" I would consider are the old lytics in signal path. 10uF and less I would replace with film capacitors. Also the contacts of switches would probably appreciate cleaning.
But once you have the boards on table then - aside from the big reservoir caps - I would replace all lytics with one pass.
Have you tried measuring your amp with RMAA? The "before" and "after" results can tell you the difference (example from Pioneer amplifier from same era, lytics changed and switches cleaned):
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Yes it is 🙂
Thank you for the into!
I think so too. I'll probably re-do the whole thing. I am cringing at the work and parts though haha. I haven't measure the amp at all.