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MC2155 filter caps read very high

lbcgav

lbcgav

AK Subscriber
Subscriber
I was testing the filter caps on an MC2155 and found that they read between 18,000 and 19,000 uF. They should be 8,000 -10%, +75%, but that's more like +125%. The ESR is reading only around .04 ohms. I'm using a Peak Atlas ESR70 Gold for the measurements, which is rated for up to 90,000 uF.

Should I be concerned with these capacitance readings on these capacitors?
 
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Same amp. Just got done recapping. Everything looks fine, sounds great. Then I started switching between the various iterations of the meters like Decibels, Watts, Watts Hold, etc. I realized that when set to decibels, the left meter wasn't working. I know this just started as I tested this before. I was thinking of replacing the ICs for the meters, but had trouble finding new LM201A replacements (such as LM209AN, LM309AN, etc). I pulled the board and swapped IC603 and IC601 and the meter started working in both decibels and watts. I guess they just needed a good re-seating.
 
I love working on these amps, besides the super brittle lamp shrouds for the meters. They crumble to nothing if you're not careful. Super glue, baking soda, and tape is what I used to put it back together.

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Oh, and the stupid piezo buzzer needs to be replaced. Other than that, this amp was a peach.
 
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I have read that the 2155 lights roast the light boxes, seem to be somewhat famous for that. Maybe it was a marantz design feature that they decided to incorporate?
 
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