Importance of recapping a SS amp?


I have an Odyssey Stratos power amp that I purchased new in 2000. It has been suggested that it should be recapped just because of its age. I've not detected any sonic decline. Is this considered standard practice with a solid state amp of this age? When I've googled it, most of hits concern vintage tube amps.

Thanks for any advice.

Jim
jmg1949
I wouldn't worry about it, if it ain't broke, don't fix it.

Many will talk about replacing caps in an amp every 15-20 years, but much of that has to do with the caps, the amp design, and the use. Caps are more prone to failure and need of replacement if the are forced to sit for long periods of time (years) without use, in excess heat (Class A bias) or other conditions. Your Odyssey is not Class A, does not run real hot, if you have been using it on a regular basis, your caps are probably in good shape for another 20 years.

I once bought a 20 year old Class A amp and sent it to the manufacturer (CODA) to be recapped. To their credit, they actually talked me out of it by telling me the caps looked great and tested great. They said the caps would probably last another 20 years.

Just relax and enjoy the music.

Cheers,
John
I agree with Jmcgrogan2.

You could pop the cover off and visually inspect the caps. I think they start swelling a little bit before they go bad and start leaking... Im sure someone else can confirm or discredit that.
Thanks for the advice. There are certainly other things I can spend the money on.
Jim
ones not being used for the long time no matter tube or semi-conductor amps will most-likely need recap. ones being used will last much longer before this replacement is needed. Usually you may develop an unwanted intermittent humm.
Gear unused for a long time (years) need reconditioning - applying lower voltage (perhaps 50%) and increasing it slowly over day or two. It is because without the voltage electrolyte eats dielectric layer (aluminum oxide) reducing breakdown voltage, while presence of the voltage rebuilds this layer.

Electrolytic caps simply dry-out over time. Each 10degC temp increase cuts life of capacitor by two. At room temperatures you should get at least 50 years. It might appear as poor control over bass (wooly bass) since dried out capacitors have higher internal resistance (ESR) thus reducing dynamics. When caps are really old and show symptoms of high ESR they should be replaced because they could explode. It is because higher ESR increases capacitor's temperature and temperature increases ESR - avalanche effect. You don't have to worry about it perhaps for 40 years (if we're still alive).
Here's the key. I agree with most of the response above. Think of high end electronic equipment that same way you would about mechanical equipment. Everything requires routine inspection, maintenance and possible repairs at some time or another. Power output transistors are typically connected mechanically to heat sinks using heat sink compound and insulators. Over time the heat sink compound dries out and the insulators (especially older mica ones) dry and crack, which will cause the transistor's case to short against the heat sink and boom. No more channel. The way to prevent this is to open the amp, remove and replace the heat sink compound, transistor insulators and upgrade the transistors to newer better, more linear devices. This is called preventive maintenance. but, it isn't needed or required until either 1) the device fails, or 2) Many years have gone by, which suggest it may be a good idea to do this before it fails.

Does one wait until their car fails before performing maintenance? absolutely not. The manufacturer often suggest a maintenance/component replacement timeline. The same is true for electronics.

Waiting for capacitors or transistors or tubes or tube sockets to fail may also take out some other components.

Here's the key for me. If I have no plans on replacing that amp, because in my opinion, I am "there", then Yes, I'll inspect the amp's components to see if there may be issues if the amps is getting on in age. Capacitors that may be on the verge of failing, swell, or leak, which is pretty obvious to see. Sometimes, they exhibit no visible problems and simply fail.

Amps with slow start circuitry tend to not stress the caps as much because the allow the caps to charge slower before connecting to the main circuitry and presenting them with full load. The life of the amp and caps and circuitry is extended.

Don't believe the hype from some that suggest that "newer" amps are that much better than older ones. This is typically not the case. But, is more in line with companies having to come out with something new every so often to keep sales up and compete with other companies.

If you are concerned, open the amp, inspect (or have a qualified tech) inspect the amp's circuitry and if the need arises, replace the caps.

But don't worry about it. Inspection and preventive maintenance is a good thing for any equipment.

enjoy
Thanks again for all of the responses. The amp has been used fairly regularly over the year so unless some sonic issues arise, I will likely sit tight for now.
Jim
Caps are more prone to failure and need of replacement if the are forced to sit for long periods of time (years) without use, that is the most redicoulas statement of all time!, the more you use and drive hard the amp, the sooner you have to replace caps!
Audiolabyrinth, from the user's perspective could be anything, from the one who fixes electronics, it's a-bit different and not so redicoulas or redukolois at all.
On one of the Kenwood receivers I was always loosing one or 2 caps once put back PCB together after fix. It turned out that all of them needed replacement after sitting and not using.
All amps age differently depending on design and use. The deterioration is slow and gradual. Maybe your thoughts were started by hearing some subtle differences. Again, Odyssey can best advise you what to do.
Jl35, exactly right !
Time and again I've listened to systems where the owner says said amp is 18 years old and good as ever.
It never is but, as you say, he's so used to the gradual decline he can't hear it.
'Again, Odyssey can best advise you what to do.'

Actually, it was Klaus at Odyssey who recommended this. I have had only good experiences dealing with him over the years but wondered what the conventional wisdom was, if any. As with many issues with this hobby, opinions appear mixed.

'It never is but, as you say, he's so used to the gradual decline he can't hear it.'

My hearing has probably declined in synch with the amp.:)

Jim
The manual for my Pass amp states that the power supply caps can start to deteriorate at 15 years.
I have a vintage Kenwood Supreme 600 from 1974. In 2006 I had it recapped, and it was overdue, but not by 17 years. You couldn't hear any degradation in sound, but the big caps had started to bulge at the bottom. After the recap, things were brighter and cleaner. Good for another 20-25 I'd say.
I asked krell about how long will new caps last, their answer, The more you drive the amp hard, hotter, louder, very long listening session's, the shorter life span of the caps for our amplifier's. That said, that was my answer since I got up-graded modded caps inside my amp, I got a total cap job, all of them, not a partial job, this maybe different with other brand's of audio, but since I own a krell amp, I am going to go with what they told me!, 10 to 15 years by misuse or 20 to 25 years by doing what krell said to take care of the amp.
Never heard of this been using power amps for 40 yrs.

In that case you are running the amp on borrowed time if its been the same amp that whole time!