Amps are broken in Marantz SR6010, fixable?

[voodooless]

So I have an aging Marantz SR6010, which has never been a reliable machine anyway, but it is what I have, and it sort of works, so deal with it .

The thing is: I never really used any of the amps and have been running stereo mode for most of its lifetime using an external amp. Until I didn't and hooked up my previous speakers directly for a while. My annoyance was great when I noticed one of the front channels cracking even at medium volume. And this was not always the case, I couldn't really figure out the pattern though. Could be heat-up, could be something else, all I know is that it's not always occurring.

So next, I brought the thing in for repairs (the volume knob was also broken, as has been customary with these things for decades). Sadly, they didn't fix the amp, just uselessly replaced a relay. So obviously that didn't fix the problem , and I'm not going to trust them anymore to fix anything ever again.

Annoying, but not a massively big deal though, I now have active speakers, and the pre-outs don't seem to have these issues.

But since last week I added some passive rears, and I'll be damned, first, they were fine, but after a while, also the right rear channel started acting up, exactly the same way: crackling even at medium volume (like -20 on volume control).

So it seems this issue affects multiple amps, which leads me to believe the issue might not be directly related to the amps themselves, especially since they haven't been running for any serious time. But question is, what could it be then? Power supply issues? That would affect all channels equally, but so far I could not identify that either. Clipping? Why at -20 dB already, and why not consistently. I do have the service manual of the thing, so have access to the schematics if needed.

Any pointers on where to start with this?

 

[JeffS7444]

My Marantz NR1608 was plagued with an intermittent headphone jack, and at first I suspected one of the many relays. But specs on those (sealed) original relays were actually pretty good, and I had no reason to suspect that they were contaminated or worn-out.

I also examined the various PCBs and saw no evidence of cracks, heat-related damage or faulty solder.

The solution wasn't what I expected! Construction of these receivers is modular, with many tin-plated interconnects used between PCBs. The insides of my receiver were still pretty clean and new, why should these become intermittent? But they had. So I unplugged as many assemblies as I reasonably could, and gave the contacts a light coating of GC Electronics De-Ox-ID #19-1902 contact cleaner, then reassembled. I then needed to squirt a little contact cleaner into the headphone jack itself, and it worked! That was several months ago, and the receiver has been 100% reliable since that time.

 

[voodooless]

Hmm, if that would solve it, that would be a cheap fix. In my case, I'd only need to check the cables from pre to amps, since if this were the issue, it would be found there. Should be a relatively simple check.

 

[peng]

Hmm, if that would solve it, that would be a cheap fix. In my case, I'd only need to check the cables from pre to amps, since if this were the issue, it would be found there. Should be a relatively simple check.

Being intermittent, and the unit being relatively new, not heavily used, I would say it is 99% connections related issues. It could be anywhere from input to output, including the speaker cables.

 

[voodooless]

Being intermittent, and the unit being relatively new, not heavily used, I would say it is 99% connections related issues.

Well, relatively... it's about 6 years old.

It could be anywhere from input to output, including the speaker cables.

Speaker cables are unlikely, I didn't use the same ones, and the speakers are not even the same. And as I said: pre-out work just fine, so no issues at all with those, so whatever goes wrong, happens after the pre-outs.

 

[xaviescacs]

I've recently repaired a marantz amplifier with similar problems, not sure though. This is the thread I created:

https://www.audiosciencereview.com/forum/index.php?threads/marantz-pm-ki-pearl-lite-repair.29967/

Little chance it can be useful for you I guess since I solved the issues replacing the relays , but who knows.

 

[JeffS7444]

Speaker cables are unlikely, I didn't use the same ones, and the speakers are not even the same. And as I said: pre-out work just fine, so no issues at all with those, so whatever goes wrong, happens after the pre-outs.

BTW, don't forget to update firmware: Some of the revision notes indicate that there were fixes done to eliminate audio crackling, though I never experienced the problem myself.

 

[voodooless]

I've recently repaired a marantz amplifier with similar problems, not sure though. This is the thread I created:

https://www.audiosciencereview.com/forum/index.php?threads/marantz-pm-ki-pearl-lite-repair.29967/

Little chance it can be useful for you I guess since I solved the issues replacing the relays , but who knows.

Well, I would not rule the relays out. They only replaced one channel as far as I know, and it might even have been the wrong one. As I said, I'm never going back there...

The question is: how likely is it that the relays of channels that were basically never used have now deteriorated?

BTW, don't forget to update firmware: Some of the revision notes indicate that there were fixes done to eliminate audio crackling, though I never experienced the problem myself.

I think I checked that recently, there hasn't been an update for quite a while, but I'll double-check!

 

[xaviescacs]

The question is: how likely is it that the relays of channels that were basically never used have now deteriorated?

In my case, the only relay that failed was the channel B one... which I had never used before.

The sound problem however is different I believe: I heard a lot of distortion that disappeared when the volume was high enough. I know very little about relays however, so perhaps different kind of problems can arise..

Perhaps you can record what you hear with a single tone, post hear, and wait for someone with experience (let's say @restorer-john, to pick someone randomly) to help you.

 

[peng]

Well, relatively... it's about 6 years old.

Speaker cables are unlikely, I didn't use the same ones, and the speakers are not even the same. And as I said: pre-out work just fine, so no issues at all with those, so whatever goes wrong, happens after the pre-outs.

Agreed, so the remaining connection(s) originated issue would be upstream. When it crackled, did it last long enough for you to troubleshoot, such as tapping on the enclosure here and there to see if it would stop?

 

[voodooless]

Agreed, so the remaining connection(s) originated issue would be upstream. When it crackled, did it last long enough for you to troubleshoot, such as tapping on the enclosure here and there to see if it would stop?

Once it starts, it doesn’t really stop unless you lower the volume a bit. I haven’t tried tapping the box, I might try that!

 

[Sal1950]

So I unplugged as many assemblies as I reasonably could, and gave the contacts a light coating of GC Electronics De-Ox-ID #19-1902 contact cleaner, then reassembled.

A good thought from Jeff here but in your case @voodooless , have you tried using the same product on level-input controls and other mechanical switches?

 

[Andysu]

do video so can hear what is happening clicking could be anything . do video so can actually hear i may have theory ?