Lifespan of a quality solid state amplifier?

I have an over thirty year old APT Labs amplifier that is still running a pair of old 1979 B&W 801's! Yes, it's a 100-watt amp into 8-ohms and runs near clipping all the time. It sounds fine.

Electrolytics are no better than +/- 20% tolerance so that wear is less sensitive than you might think to sound. Caps in the more sensitive audio path that are non electrolytic give you a better circuit life if anything. There is no "proof" that exotic caps sound better over just last longer (at a price). Large electrolytics in the power path are cheap to service, too.

Most smaller electrolytic caps, if mounted right to lower lead inductance, often have the lead end (where they leak) SHORT and right to the PC board. You can't see the caps leaking when they do go till it's too late. Large power stage electrolytics are faced "up" with the terminals using screws. Inductance isn't as important in the DC path. You can watch these for signs of deterioration.

...I will not be responding further since you clearly have no intention of accepting the overwhelming body of evidence that contradicts what you say...

No, caps age. The thread was how LONG and how WELL and amp can sound as it gets older. To go to some of the extremes in this thread would be to toss out an amp as soon as time changes. The discussion was NEVER that caps don't age (you seem to be hell bent on thinking I don't know that), it was how gracefully they age. Nothing contardicts what I say. A fifteen year or older amp can sound pretty darn good. Remember too, that caps are selected to provide the best service and sound where they are used. SS is a wonderful thing...for a long time.

No, you just push statements you're trying to justify making using my post. Do it on your own, please. I did NOT say counter to what want to say, I did say the effecets are less severe than MEASUREMENTS would lead you to believe! READ it again. If the caps aren't looking bad and it sounds good, keep on trucking.

If you keep electrolytics out of the audio path, a power supply has less effect on the overal "sound" than touted if the supply was decent to begin with. Older electrolytics aren't the same as new, but the FUD is overblown. True, gross failure not withstanding. ESR change in a electrolytic capacitor in a good circuit doesn't doom an amplifier to a severly limited lifespan.

Large electrolytic capacitors are GROSSLY variable right out of the box. But, on the power supply side it makes little difference to the sound. People LOVE to talk ESR, but know little of how it effects a circuit..it just "sounds" good to pretend any change is audible. We also take RF circuit design and pretend it works at audio (basically DC realtive to RF).

http://sound.westhost.com/articles/capacitors.htm

YOU need to read-up on facts about types of caps and degradation and why, not to mention their sound, or lack thereof. There is more snake oil in audio than in snakes.

When I say the amplifer sound fine, I mean it. As good as a new Mark Levinson? No, of course not. But to simply say it is older so it can't sound fine is nonesense. I listen to it (fact), and you simply read about it (no fact at all!). I also have New KISMET ODYSSEY amps running C4's, so I do happen to have a new reference.

So I LISTEN to this amplifer which goes a LONG way to saying the older caps are plenty servicable, still. "Comments" of differences in sound are pretty baseless since you haven't even listened to the amplifier. True, I don't take out the caps and measure them all but the point of the post is OLDER amps can still sound fine. Mine does. Are the caps the "same"? Of course not.

I gave you the thread on CAPs in power supplies and circuits. Read it. Unless the caps are real bad, it isn't a "major" thing at all as they age. The "rant" is easy to "listen" to. So many want to read till they agree with the "words" and never listen.

How many of you even HAVE an amp that is thirty years old to listen to? Most here that do have a twenty to thirty year old amp seem to say the experience is like mine which is not too bad. And, Like I said for the third time, big caps do age in the power supply and are easy to change out. The cans face "up" with the leads on top, usually, so inspection is easy. If you have a twenty or thirty year old amp you want to keep, simply change them out.

I do have an older amp, and it runs fine and the caps are physically sound (no bulging, leaking. ETC). No, the caps won't test the same as new, but the amp is far from "major" different to newer reference equipment relative to the APT one's ability in the first place. The supply can still deliver OK bass transients and the amp is very quiet.

My "one" amp is FULL of large caps, so the statistics are in the favor of caps doing well over twenty plus years if they are of good quality. If it was ONE cap it would match you smoker anlogy. I have statistics on several in the same amp under the same stresses. This is called a large sample population. HEAT is the major enemy of electronic parts. A 10C difference in service temperatures can add an easy ten years to a components life. And, this isn't the ONLY unit I have that is older and working fine, and they have caps, too. So say bye-bye to the lone cigarette man.

When is an amp "true" to you? Since you don't accept that an older amp can sound fine, not like new, there is no truth other than what you read. When do you "decide" your amp is all of a sudden "MAJOR" different? It just all of a sudden goes "major" does it? Do you have an identical new amp that never ages to reference it to? You'll need one as the sound quality does diminishes slowly.

I find it interesting that so many reference what we "read" and not so much, if any, on what we hear. I'm as sober as can be and SS amplifiers and lesser audio circuits age very well with good quality parts. They don't "massively" change except for total loss / leakage.

I have NEVER had a SS unit die from capacitor failures. Transistors, yes. Diodes, yes. Resistors, yes. These parts have been replaced and all upstream and downstream components have been fine (except failed output transistors, they over current lots of parts). It might be fairly argued when more than one component fails, it's hard to point to the one that started it all. But, Phase Linear 400 amplifiers in the day blew outputs all the time and I NEVER saw the capacitors replaced.

So again, someone decides my "position" that power supply caps don't matter is simply silly. Sure they matter, but much less so over time than people want to "read" verses "hear". Most good supplies are well over the design spec of their peak current ratings to provide headroom. As the caps age, the headroom does diminish. But it is still "servicably" good after decades of service to sound nice. Most amps run far under their design limits, so transients are still reproduced well.

But, if an amp ages and simply goes "major" all of a sudden because we simply read that they do at some point in time, than many people will be happy to buy these amplifiers!

The near end of "major" is fifteen years and the far end of "major" is thirty years. Your service temps are far more important to service life than any other variable except the quality of the part. My ears say so, and so does inspection of my equipment. You can't be any more sober than that.

You have no facts, just "faith" that can't be proven wrong, even with the FACTS!

First, the thread was, are older amps, or SS in general, serviceable and good sounding at older ages? YES, they are.

I offered how old? Even thirty years old! I have an APT 1 power amp S/N E02248 and use it all the time, as is the PS IV pre-amp S/N 1718 purchased in 1981. Besides, I lied, they are both OVER thirty years old. I'll send "proof" to anyone who wants to see the receipt! I have the shematic if you want to count the number of electrolytic capacitors in the amp! The circuit is a very statistically valid representation of OLD electrolytic life span.

You're invited over to my Mom's house to listen to this "junk" on thirty one year old B&W 801's (S/N 001364 , 001363) and guarantee you you will NOT want to go back to your boom box.

Go to this thread and READ IT! This is measured FACT on cap circuits and parts.
http://sound.westhost.com/articles/capacitors.htm

Until an amplifier circuit of any sort get well outside the passband requirements to pass music (slew rate, frequency response, current delivery ETC) the sound is still acceptably good. Especially at the level music is listened to 85% of the time (which should be 3dB or more below the amps peak output capability).

Proper electronics use capacitors that remain benign to aging where required (poly or Teflon in audio path as an example). Or, excessive requirement can be built-in up front to provide a useful life (HUGE electrolytic cap banks in amplifiers due to ESR increase). This is pretty straightforward use of materials and cost trade-off.

A so called DPA (hey, this MUST be audible if we have an acronym!) analysis is 100% meaningless until such time the double blinded tests PROVE age related degradation is audible in a GIVEN (not any other, they are all different) design. I see no facts here, just wishful thinking.

As long as we see invisible elephants in the room, there is no fact but faith providing fiction. Everyone is afraid to NOT see the invisible elephant, so the audio art gouges those who can see (or hear) the invisible elephant trumpet.

Sorry everyone, I'm not taking the bait to be like the rest of you. I DO NOT hear my older equipment sound "profoundly" bad...just the opposite, it sounds profoundly good for its age. All hundred or so electrolytic caps still seem to be doing their thing in the amp and pre amp (when the old preamp SWITCHES are clean, but that isn't the caps!).

Silly lines applied WAY outside this thread are unproven, too. What is your invisible elephant’s size or time frame? Oh how loud does it trumpet before you can hear it be profoundly different, or unacceptable? You make it up as you go.

"...Caps do matter...
...Caps do have a profound effect on how an amp sounds...
...Caps do age and affect the sound...."

Caps matter if you don't have one (utter failure) way less so if you do and they are used right, and they are simply older. An amp can function very well in this state...mine is. This statement is so utterly obvious to be meaningless (or why would we have caps at all?).

Profound? No, that's an utter garbage statement that is a great sounding adjective, but it holds no double blinded FACT. If it is PROFOUND, like a light switch turned on and off, this thread would answer itself. Someone PLEASE tell my old amp and pre amp to become "profoundly" bad.

Caps, depending on the type and headroom can "maybe" degrade enough to effect the sound. If the amp is several times faster, cleaner and more dynamic than the passband information, it may well be THIRTY years before the amp gets noisy or clips enough to be "profoundly bad". Clipping is the power supply DC voltage rail capability in an amplifier, which does vary with transients / load modulation. But, is the change enough to be “profound” verses a much “softer” degradation? In big amplifier power suppliers, ESR is important, but it has to degrade to a point you HEAR it, not just measure it. I do not concur that a change, any change in ESR, is audible. Where is the fact in that? Can some designs eventually get “weird” as ESR goes up? Sure, but this is happening WHEN not that it doesn’t EVENTUALLY happen. We're talking about how LONG a design capacitor ages, not that it doesn't fail...eventually.

We use HP analyzers at work that are a decade old, and are checked regularly each year. They get a 100% bill of health with minor bias adjustments (which can be done on any amplifier). They make measurement orders of magnitude more critical than an amp playing music.

We all seem to be so aggressive to hear "anything" that we forget it is also OK to hear NOTHING between components. But no, we all take a drag on the same joint and ask each other if you feel high. When the “group-think” mentality says so, than we are high even if we made it up (no one venture fourth that they AREN'T high for fear of not being cool!)

So no, I'm not in this peanut gallery that "hears" the equipment age every day simply because 24 hours passed by. When I hear it I'll make comment on it. Do caps change? Yes. Can you "measure it"? Yes. Are the measurement so profoundly different all of a sudden you wretch away the minutes listening to them? No. Can some thirty-year-old amps (and even speakers) age so gracefully as to sound good at thirty? Yes.

One last thing, who CARES if a cap all of a sudden vaporizes at 32 years? You’ve had your use from the unit so why the FUD when it does die? Oh it surely will...and THEN that big elephant in the room is...well crap, he's silent. If that scares you, just change them at fifteen years.

Some time this site reminds me of Forrest Gump when he stopped running. One poor guy spoke for the crowd and said, "great, now what do we do?" We'll, use your ears and stop pretending to hear everything simply because someone else says what, when, where and how much.

That silent curtain of "faith" is so easy to hide behind. It replaces real knowledge and that's a shame. Hearing a difference is not knowing what made the difference. Enjoy what you hear, don't make-up what you know. And use your own noggin.