AV Processor: Repair or Buy New

[gene_stl]

My Yamaha rx-v2600 stopped working a few years ago. A replacement capacitor in the power supply fixed it, for a modest cost.

A replacement capacitor in the power supply. Not all the caps in the unit. for $1500. Sometimes caps like this are reasonably replaced in pairs. Sometimes you just put in the one that failed. One failing does not predict when the next one might fail. (an exception to this is if you are a victim of a bad lot of original capacitors as happened a few years ago in professional amplifiers. A chinese knock off cap manufacturer, hired a guy away from a japanese company and he caused the manufacture of a bunch of caps that were supposed to copy a particular type from his former employers. But his formula was not quite right and there was a raft failures in pro amps including some Crowns and other respected makes. I have one waiting to be recapped and it will get all four big caps replaced. Even though only one of them splurped. There have been other incidents like this also in the computer equipment part of the world)

 

[par4ken]

I generally take a very dim view of undiagnosed electrolytic capacitor replacement. If it ain't broke , don't fix it. Usually when capacitors cause problems it is only one or a couple out of all of them that has dried up or poofed. You just replace that one and it starts working again. That is why God made service technicians.

I have been testing my late seventies gear on a good test bench lately and am AMAZED at how it all (so far about half of it) just keeps perking along and meeting really great specs. (Down in the noise of the test gear mostly). This includes three Pioneer Elite M-22 Class A Power Amp/Toasters. If anything was going to dry up these would. But this points to one of the reasons not to. Are you sure your self appointed recapping tech, knows how to pick the correct capacitors for your application. Does he guarantee a measureable and measured performance improvement?

This is a current fashion in audiophilia, that is , as usual, a method of separating money from audiophiles, who are not electronically trained nor knowledgeable. I have seen military surplus test gear from the 1930s and 40s, that still works fine, and I prefer to work on scientific gear from the 50s through late 70s because it is usually repairable.

It is correct that you can often ressurrect a dead computer motherboard by replacing the electrolytic capacitors in it and I have done this repair many times. Mostly on terminals from the 1970s that were on 24/7 and are no longer made. About 60+% came back to life with cap replacement only.

The reason you know snake oil is involved, is that they not only tell you it will start working again (if it's not working), but whether or not it is working, they tell you it will sound better. Just my not at all humble opinion. ymmv

I tend to agree with you in that elecrolitic capacitors are more durable than many people give them credit for. I have some 50 or 60 year old equipement that still functions, with all original caps.

Chinese capacitors on motherboards have given problems after only a couple of years. I remember Uniden satellite receivers that fried the capacitors after a couple of years due to high operating temperature.
I have a Marantz pre-amp from that eighties that I'm still working on that had/has many bad capacitors on it.

On the other hand if you are replacing one capacitor it doesn't hurt to do more if not all of them. Wima make nice little film capacitors that can often replace electrolytics in vintage equipement. Multiple electrolytic capacitors in the signal path can affect sound quality and film capacitors rarely fail.

In power supplies you can up the value of the capacitors for better ripple rejection, the newer capacitors are much smaller than the originals.

 

[MidiMagic]

Electrolytic capacitors tend to last longer if they are in daily use.

They go bad faster if they are in stored equipment.

 

[gene_stl]

If a piece of equipment has been stored power off for a long time AND has a linear power supply I bring it up on a Variac slowly. This allows the capacitors a little time for reorienting the internal foils in response to the electrostatic force of the DC.
I also have just switched them on and never had one pop but there is always the future.

 

[Sonik Wiz]

I tend to agree with you in that elecrolitic capacitors are more durable than many people give them credit for. I have some 50 or 60 year old equipement that still functions, with all original caps.

Chinese capacitors on motherboards have given problems after only a couple of years. I remember Uniden satellite receivers that fried the capacitors after a couple of years due to high operating temperature.
I have a Marantz pre-amp from that eighties that I'm still working on that had/has many bad capacitors on it.

On the other hand if you are replacing one capacitor it doesn't hurt to do more if not all of them. Wima make nice little film capacitors that can often replace electrolytics in vintage equipement. Multiple electrolytic capacitors in the signal path can affect sound quality and film capacitors rarely fail.

In power supplies you can up the value of the capacitors for better ripple rejection, the newer capacitors are much smaller than the originals.

Interesting discussion on repairs, caps, etc. The oldest operating gear I still use today are my Adcom preamp & 555 power amps, all from the late 80's. It seemed extravagant at the time to buy 2, $600 power amps & the preamp wasn't cheap either. But they are both working like new even today. There's a little transformer buzz in one but that's it.

But I did have a glitch soon after buying when I mated them up with Infinity Kappa 8's for the fronts & Kappa 7's for the rear. I was getting adrenaline rushes just testing how incredibly loud & clean this combo could do. Then one day I cranked the preamp to 11 & put on one of those early digital demo CD's. This was one that startled out lower level & grew into a gigantic "WHUMP" that lead into the theme from Star Trek. And the front chs went simply silent. I checked the output fuse on the front amp & it was good. So back to the stereo shop for warranty repair.

But the interesting part was what happened while the unit was in house. Adcom sent out a service bulletin saying these amps when paired with "certain Infinity speakers having very low impedance" may have the driver transistors go kaput. They recommended upgrading the driver transistors to a different type & something else I don't remeber for sure. Because this was an ethical shop they suggested I bring in the rear ch amp (which was working fine) for the upgrade, no charge. So I did. Smooth sailing ever since. Oh, that driver upgrade was the main change in the Adcom 555 mk II that came out about a year later.

 

[marpow]

I am not going to buy it, but it has just been released.
https://myemail.constantcontact.com...essor.html?soid=1104107397248&aid=w5_hT6sqa9A