Hi.
I'm not super knowledgeable about amps but i know some electronics. So thought I might give it a try.
Setup:
Nad c352
Two Jamo CBR 1302 speakers
Description of problem:
When the amp has been on for a couple minutes, less than 20 min, the right channel goes loser and lower till it is totally quiet.
If i turn it off and on again it still has the problem. But if it's off for some time( a day or so) it starts normal again then goes quiet. So I'm thinking it's some temperature problem...
Anyone here have an idea of where to start?
My regards
-Noah
I'm not super knowledgeable about amps but i know some electronics. So thought I might give it a try.
Setup:
Nad c352
Two Jamo CBR 1302 speakers
Description of problem:
When the amp has been on for a couple minutes, less than 20 min, the right channel goes loser and lower till it is totally quiet.
If i turn it off and on again it still has the problem. But if it's off for some time( a day or so) it starts normal again then goes quiet. So I'm thinking it's some temperature problem...
Anyone here have an idea of where to start?
My regards
-Noah
Thermal shutdown of output devices or power supply.
Start with heat sink compound and tight mounting.
Start with heat sink compound and tight mounting.
https://www.diyaudio.com/community/threads/nad-c352-question-about-warming.370029/
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwio9quL8fP4AhUfxDgGHSzmBDMQFnoECBQQAQ&url=https://www.diyaudio.com/community/threads/nad-c352-question-about-warming.370029/&usg=AOvVaw2TuCnwCLR3xUbyLfEN-wBe
Seems a common issue...
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwio9quL8fP4AhUfxDgGHSzmBDMQFnoECBQQAQ&url=https://www.diyaudio.com/community/threads/nad-c352-question-about-warming.370029/&usg=AOvVaw2TuCnwCLR3xUbyLfEN-wBe
Seems a common issue...
Working for a bit before fading out leaves out corrosion of the headphone jack switch.
I'd check the power supplies with a dvm & some alligator clip leads or pamona grabbers (better). At 30 years electrolytic caps can have leaked & dried up, frequently quitting when they get a little warm. The schematic diagram is available on several other c352 threads on this forum. Visual inspection for leaky capacitors catch only about 1% of culprits. You can buy a $120 ESR meter to check capacitors and replace them if you can't bear to part with your historic old garbage. Change only 2 at a time and sound check, newbies make a lot of solder errors. Mark board for polarity before removing any e-caps, they can explode if inserted backwards.
Warning to newbies. Probing an amplifier with the power on can cause electricity >24 v to cross your heart, stopping it. Use only one hand at a time and clip leads. No jewelry on hands wrists or neck, 1 v @ 30 amps through a ring can burn your flesh to charcoal. Wear safety glasses, parts sometimes explode.
I do heat sink compound & new mica washers only if I have to remove the output transistors for cause.
I'd check the power supplies with a dvm & some alligator clip leads or pamona grabbers (better). At 30 years electrolytic caps can have leaked & dried up, frequently quitting when they get a little warm. The schematic diagram is available on several other c352 threads on this forum. Visual inspection for leaky capacitors catch only about 1% of culprits. You can buy a $120 ESR meter to check capacitors and replace them if you can't bear to part with your historic old garbage. Change only 2 at a time and sound check, newbies make a lot of solder errors. Mark board for polarity before removing any e-caps, they can explode if inserted backwards.
Warning to newbies. Probing an amplifier with the power on can cause electricity >24 v to cross your heart, stopping it. Use only one hand at a time and clip leads. No jewelry on hands wrists or neck, 1 v @ 30 amps through a ring can burn your flesh to charcoal. Wear safety glasses, parts sometimes explode.
I do heat sink compound & new mica washers only if I have to remove the output transistors for cause.
On another thread it is mentioned that the electrolytics are in a place where they get exposed to heat.
Read up the threads, then replace the big caps.
And do check the transistor temperature with a probe, PT100 type probe to digital voltmeter should be OK.
Read up the threads, then replace the big caps.
And do check the transistor temperature with a probe, PT100 type probe to digital voltmeter should be OK.
Pull out the preout/main-in link and use a single rca cable to narrow down the culprit is the first thing that I'd start with.
