life span/failure rate of filter capacitors?

should do basic maintenance after 15-20 years, replace all of them, have factory give a overlook at everything.

i was told after about 19-20 years, start looking for a warranty, or i mean the company who built the amp.

Electrolytic cap lifespan is unpredictable! My Sumo Andromeda is still going strong while my BEL 1001 and GAS Son need new caps.

Before 2000 I would have said that generally 20 years for filter caps kept warm.

I think newer caps should do better, around 30, especially if high temp.

Caps may bulge or leak before complete failure, or get unusually hit compared to their peers.

Caps do sometimes go through poor quality issues which may cause premature faiure.

If in doubt have it recapped with the highest possible temperature ratings. More expensive, but higher longevity.

I seem to recall reading that thread or another elsewhere with Cary amps of that vintage. I ran Cary SLM100 monoblocks back in day, had the well known issues with Jensen coupling caps, also had issues with maintaining bias on power tubes and occasional fuse blowing, I'd replace those caps just to be safe, lots of inrush current with your amp, stresses the caps.

@immatthewj,

@jasonbourne52 Wrote:

Electrolytic cap lifespan is unpredictable! My Sumo Andromeda is still going strong while my BEL 1001 and GAS Son need new caps.

I agree! I bought my Luxman B-12 mono block amps new in 1977, the two main filter capacitors were 15,000uf 63 Volts and lasted 30+ years. And were up to spec when I sold them. If you are occasionally blowing a fuse, my advice would be to send the amp to Cary Audio and have them check it out. 😎

Mike

Something i do not agree is changing the temperature specs on vintage equipment.

If at 85 deg replace with same rating, and check to improve in other areas as voltage, tan δ, esr, etc ( depending on position)

Last, why should a higher temperature rating be more expensive? 

The truth is that after 20 years you maybe on the edge, and say maybe because i believe that good quality caps can last a very long time.

Nelson Pass stated that even after 20 years most of his products do not

need new caps. Maybe because he uses a lot of them?

Thanks all.  @ditusa , @arcticdeth  , this is the thread that got me thinking about the subject

and after reading this thread, and a couple of quite recent threads related to the SLP-05, I don't think I want to send anything back to Cary for any reason.

A couple of years ago I took the bottom off of my V-12 to change the coupling caps, and from the looks of it, I wasn't thinking that the filter caps would be too bad a job,  And I was thinking I could probably get some from Partsconnexion?   I remember at the time, someone from another forum (AA) was helping me troubleshoot (via email) the signal caps and his opinion was that the large electrolytic caps were not a common part to fail.  So I kind of put it out of sight/out of mind.  Until I read that thread that I pasted above.

When I had my Cary amps, I was able to successfully undertake all repairs/upgrades with direct help from Dennis Had, great guy. I know he's no longer affiliated with company so perhaps not so great on servicing his designs?

I'd go for the diy route on those caps, as I recall my SLM's, shouldn't be that difficult. I deal with Partsconnexion  quite often, very good supplier. You may also find the caps you need from places like Mouser, Allied.

Thanks for the reply, @sns , I remember (and miss) the Dennis Had days. There used to be a wonderful individual (Kirk Owens) in tech support who was quite patient and thorough and walked me through about every problem or upgrade I ever had with one of my CAD products.  I am thinking that Dennis is probably as busy as he wants to be with his Inspire line of SET amps and his preamps. 

Is it your opinion, then, that I should go ahead & replace those 21 year old caps?

If it were my amp I'd do it, minimally it will allay your doubts in regard to their possible failure, and if you're keeping amp for the long term they'll have to be replaced at some point.

Thanks, @sns  , I would like this amp to last longer than I do, if that is possible.

I just got done looking on partsconnexion, & this may not be as easy as I was thinking it would be (finding one with the specs I want).  I'll do a search on the others you mentioned--Mouser, Allied.

If worst comes to worst, I guess I can email Cary & try to buy four of them there.  Back in the 90's I bought a "power-bank kit" (added filter caps and an umbilical cord to attach them with) for another Cary amp I had, and I am going to look, but I am thinking that they were the same value.  Cary's prices for signal caps are crazy, though, and I suspect they would be for filter caps also. 

Regardless, thanks, & I'll look at those other places you listed.

Depends on a lot of variables, size of the capacitor (larger caps don't get hot as quickly as small caps) if it's placed near hot areas of the amp and quality of the capacitor. Most of the really large caps of high quality usually last a lot longer than all the smaller caps in an amp.

Eric has provided good advice.  Plus you may also begin to hear fluctuations in the music with power capacitors.  If you are in the NYC area I can take a look at your unit.  On Parts Connexion look for Nichicon Super Through parts.  You can go up in value if you have to just make sure that they fit in the space you unit has.

Much has to do is how much demand on them in the circuit ,better to have more smaller caps lower distortion ,  how hot is the area and how much use .

failure much higher in amplifiers ,quality too of the caps has a lot to do with it . 
caps get dried out as they age .

Eric has provided good advice. Plus you may also begin to hear fluctuations in the music with power capacitors. If you are in the NYC area I can take a look at your unit. On Parts Connexion look for Nichicon Super Through parts. You can go up in value if you have to just make sure that they fit in the space you unit has.

Thanks, @bigkidz , I just did a search at PartsConnexion for Nichicon Super Through Electrolytic caps, and surprisingly they came up then when they had not came up before. However, not the value that I believe are in there presently (560uf 400v).

As far as @erik_squires ’ advice, this amp is a 2001 model, and I did have the bottom off two years ago to change the signal caps and at the time I was looking at and checking the values of everything I could (because it was a biasing issue that I was trying to fix) and those large filter caps appeared good from a totally visual perspective, and I remember that with a cheap Chinese capacitor checker from Amazon, they tested within parameters.

It was just that thread I pasted above that got my ruminating on this. And I am curious about this: I took this amp out of service in 2010 and didn’t put it back in action until quite late in 2017. (And for a couple of years prior to 2010 I barely, if ever, used it.) Should I look at these caps as 21 year old filter caps, or as 14 year old caps?

I am in Pa., in the Pitt area, btw.

Thanks.

It's  a lottery, but 20 years is good going. That said, I have a pair of Meridian active speakers in my garage that are still working 35 years on. It kind of depends on whether you believe in preventative maintenance or are a kind of fix it when it breaks person.

Each 10degC temp increase shortens capacitor life by 2.  It is simply drying out of electrolyte.  Drier capacitors have higher ESR.  At certain point current thru capacitors causes internal temperature increase.  Temperature increases ESR and higher ESR increases power dissipated inside increasing temperature further.  It is Avalanche effect that can cause explosion.  To prevent serious damage all electrolytic caps have some form of pressure relief - either rubber plug or cross cut that weakens one side.  Hot capacitors should be replaced as soon as possible.

@audioman58 

caps get dried out as they age .

and does that statement apply to caps in units that have sat unused for a number of years?  My amp didn't see much (if any) use from '08 through '10. and in '10 I officially unplugged it and it was dormant until nearly the end of 2017.

@yoyoyaya 

It kind of depends on whether you believe in preventative maintenance or are a kind of fix it when it breaks person.

I generally like to fix stuff before it breaks.  Particularly stuff that might cause a lot of damage when it breaks.

@jasonbourne52 

Electrolytic cap lifespan is unpredictable! My Sumo Andromeda is still going strong while my BEL 1001 and GAS Son need new caps.

how much life is on the caps in those units you mentioned?

+1 kikanki 
If you want the amp to last, replace the capacitors. Have someone use higher temperature rated caps whenever possible. I have amplifiers that use components that are unobtainable so preventative maintenance is a requirement for me.

Note that loss of capacitance would result in poorer filtration and eventually an increase in your noise floor.

Nelson Pass is one of my audio idols, but I'm not sure his words are entirely relevant to the OP.  Cap lifetime may not be the same in tube & ss amps.  The energy is stored at a much higher voltage for tubes, ss power supplies hold a lot more charge.

Not all electrolytic caps are created equal. Some have high temperature ratings (good), higher mtf (good), higher ripple current (good), higher esr (bad). Thing is, each one of these parameters can be important, so try to find out everything you can about the caps you have, and specify a cap that is at least as good in every respect.

I buy all my electroytics from Digikey (no affiliation). Great company, tremendous inventory, next day delivery. And no surprises.

(And I assume that the filter caps are the large electrolytic caps with the screw in terminals?)

I'm pretty sure you are speaking of power caps. Filter caps are the small uF units that filter out unwanted signal.  The big (blue?) ones with threaded connectors are your high voltage supply for the valves. 

Power caps are not as critical to sound as the filter caps. 

For me, I prefer to buy from the manufacturer as it assures me of the correct part and quality. It saves me from errors and gives me recourse if there is a problem with the component. Caps are cheap compared to other amp parts like valves, transformers, etc. so even if you pay a higher % markup from the mfg. it's still a small $ number. 

@immatthewj  - if the amp is idle then those years typically do not count but it all depends on how much is was run for the 14 years.

Like I mentioned above, you can use a larger value but make sure they fit.  You can call Chris Johnson at Parts Connexion and ask his advice as he was the manufacturer of Sonic Frontiers products back in the day.

Actually power caps are not as critical but they do have an impact on sound especially on bass response and clarity.

Happy Listening.

@audioman58   IMO capacitor dry out powered or not.  Unpowered capacitors are likely at lower temperature drying slower.   Electrolyte tends to eat out dielectric (aluminum oxide) reducing breakdown voltage, while presence of the voltage rebuilds this layer.  Gear (or caps in storage) unpowered for many years (likely >5), should be powered at lower voltage (like half) increasing it slowly (Variac) over at least a day.  Unfortunately SMPS often don't work at all below certain voltage and output capacitors cannot be fixed that way.

One thing well documented which at Coda very good engineering Doug -Nelson 
pass engineering team before Nelson went solo in mid 90s.

Coda always leave low voltage on  to keep the circuit warm and caps partially charged ,

warmup time is less, easier on the circuits , and everything last longer .

that’s why Coda gives a solid 10 years warranty.

bryston  May still give 20 years not sure on that  though.

(And I assume that the filter caps are the large electrolytic caps with the screw in terminals?)

I’m pretty sure you are speaking of power caps. Filter caps are the small uF units that filter out unwanted signal. The big (blue?) ones with threaded connectors are your high voltage supply for the valves.

Power caps are not as critical to sound as the filter caps.

@yesiam_a_pirate , I won’t lie about it--electronics/electrical is a weak subject for me. I do understand some of the basic fundamentals and I can remove & replace and solder and desolder, but I really do not understand much about the principle of operation of what I am working on.

So thank you for trying to help clarify this for me. Would you mind taking a quick read through this thread (this is what got me thinking about the subject, as I own basically the same 21 year old amp, except mine is in stereo, not a mono block . . . and unfortunately, the pics are no longer available that the OP had attached to his thread.) Some where in the thread, the cap that "exploded" was described as having screw in terminals, and it must have been filled with oil, and then someone remarks that he thinks that it is a "filter cap." A power cap does sound more like what I thought it was, and I have had the bottom off of my amp before and there are only four caps with screw in terminals and they are the largest caps in the amp. And I just did look at the owners manual, and now I believe that you are correct, as it says: "POWER SUPPLY CAPACITORS 4 - 560 MFD @ 400 volts".

@immatthewj  - if the amp is idle then those years typically do not count but it all depends on how much is was run for the 14 years.

 

Like I mentioned above, you can use a larger value but make sure they fit.  You can call Chris Johnson at Parts Connexion and ask his advice as he was the manufacturer of Sonic Frontiers products back in the day.

 

Actually power caps are not as critical but they do have an impact on sound especially on bass response and clarity.

Thanks for the input, @bigkidz  , I am thinking that I had it wrong because someone in the thread that I was referencing used the wrong nomenclature and, I am, in fact, referring to the power caps.

I have been to the Partsconnexion web site doing searches, and in the electrolytic cap section,I cannot find the value I am looking for (400 v, 560 microfarad) with screw in terminals.  I didn't get started until too late today, but I will give Partsconnexion a call tomorrow and see if they have some that I cannot find on their site.  If all else fails, I will try calling the Cary Direct sales department (because there is no telephone tech support there anymore) and see if they can or will sell me a set of power caps over the phone. 

The thread that I pasted above it the reason I think it might be time to change these caps, as it sounds like it is a nasty scene when one "explodes."

Since you are blowing fuses, the amp is pulling a lot of current during warmup time. If the filte r capacitors are the cause, then the rectifier tube (if the amp has one) is being stressed an could be damaged. Certainly, replace the caps and the rectifier tube (probably beginns with a 5) if you have one. If the rectifier is solid state, it's proably OK. Happy listening.

@immatthewj  - let me know what happens  I am in New Jersey and can repair any audio component.

Thanks, @bigkidz  , I will remember that.

As it stands presently, I do not think I am having a problem with the amp, but reading that thread that I continue to reference from the OP with a 20 year old V12 which had a (what I am now sure is a ) POWER CAP "explode," got me thinking that I'd rather act proactively than wait to have to clean up a huge mess inside the chassis.

What is probably worth noting about the blowing of the 3A SB AC power fuse is:  that shortly after I bought this amp in 2001 I did a DIY mod (with advice & parts from Cary) that added the Cary Powerbank (which is an external bank of four more power caps, and I cannot find the specs of the value for those caps, nor is it stenciled on the outside of them) via an umbilical cord of sorts.  And I did like the effect--more bass punch was the most noticeable thing, and back then I wasn't having any problem with anything.  Then, in '08, my listening decreased and may have even ceased, and in '10 I officially unplugged it.

But to the AC power fuse blowing:  near the end of '17 I took it out of mothballs and went back & hooked it back up to the power bank.  After a while it started blowing that 3A SB AC power fuse with an increasing regularity:  so much so that I kep a bunch of them on hand.  Finally I decided to use it without the power bank, and, lo and behold, now it only blows that fuse on a very occasional basis.  So I am pretty sure that the power bank did have a cap that was going south, right? 

But I do not want to wait until one of the 21 year old power caps inside the chassis of the amp, itself, goes bad & "explodes."  That's what got me on this latest OCD quest for information.  Changing the power caps themselves did not look like a problem, but so far I haven't turned up any of that value (400 v 560 mfd) with screw in terminals on my internet searches.  But tomorrow I am taking your advice & putting in a telephone call to Partsconnexion.

Thanks again.   

Ask for Chris Johnson and tell him Peter From Vu Jade Audio told you to contact hem.

Thanks, @bigkidz  , I am going to call Monday (after the X-mas holiday, so if there is any holiday madness going on at Partsconnexion that will be done with).  Thanks again.

In my experience, replacing the parts in the power supply section with better parts quality yields a sonic improvement.  Last night we finished a Spectral power amplifier in stock form was nothing special.  Replaced the two large PS caps with Nichicon, some other PS caps, resistors and plugged it in.  Much better that I would consider buying this SS amplifier for myself now.

In my experience, replacing the parts in the power supply section with better parts quality yields a sonic improvement.

@bigkidz  , I can believe that.  You were saying that it is okay to go up in value; the manual says that the power caps in this amp are 400v and 560 microfarads.  If Parts Connexion does not have electrolytic caps with screw in terminals of those specs, you are saying it is okay to go up to the next size on both values?

Thanks/Matt

@immatthewj - yes go up a size.  Make sure that they will fit first.  Mitsubishi caps are also good for the power supply, they usually run a little smaller.  Next option is Michael Percy Audio.

PM me with any questins.

Thank you!

So all of this is based on an anecdotal 'exploding cap' experience from some dude?.. I've embraced capacitors as a topic across audio enthusiasts; the mystery around them, the (at times) compulsion to replace, the continual attribution of any technical or sound issue towards capacitors - it's an interesting mental phenomenon, reminds me a bit of UFO and alien stories. First off, I probably don't believe the exploding cap story, maybe, but I'd bet against it happening. I've seen guys mistake common glue as leaky caps continually - they don't know what they're looking at. Large power caps, probably not too far out of spec would be my bet, and if the amp gets that hot continually it might signify another issue. The higher the temp rating, the less 'audiophile' the cap usually. I agree with the poster above there are far more important caps to focus on - filter, but also the many across signal, and usually always good practice to see where you can replace with film wherever possible. It's the small ones which fall out of spec, have a direct impact to signal while in the path, and have the most improvement to sound quality when replaced/upgraded.  

Yes, @rickysnit  , all of this was based on me reading this thread. 

Since I do not know whether 21 year large electrolytic power caps are at risk of catastrophic failure, I thought I'd ask here where there is a population of users who might, in fact, know.  I thank you for your opinion on the subject.

ok, I read the post, that is quite a bit different. Backfiring amp! lol Good thing you don't have one in that kind of shape!

The point is, @rickysnit , the OP of that thread that got my attention did not have an amp in that kind of shape until he did. 

No, I’d bet something happened. A mod gone wrong, there is something missing. Anyway, I think it could be universally agreed that type of outcome is significantly unlikely in any normal scenario. Some other poster suggested rectifiers, there is something very abnormal with the power, it's along those lines, I'd put money on your amp being fine until you want another brand/type..

I’d put money on your amp being fine until you want another brand/type..

@rickysnit , I am hoping you are right; I’d like this amp to outlast me.

I did DM the OP of that thread, and he told me that Cary did get it serviceable and I am going to paraphrase, but he said that Cary gave him the impression that a smaller cap caused the power cap to fail. Electrical & electronics is a weak subject for me; I only know how to solder & desolder & remove & replace & read a MM, so I have no idea if that makes sense or not.

Or it could be a strange individual making up stories for forum entertainment.

Or it could be a strange individual making up stories for forum entertainment.

@rickysnit  , I suppose that anything is possible, but if you go through that thread you will note that the OP had photos (from a shared photo site that are no longer available) of the inside of his amp, and other members of A'gon did comment on those photos.  So if this was a made up story, the OP certainly went to what I would consider extreme lengths to do so. 

Well, whatever I suppose. Are you going to replace to caps? If so, I think you could go nicely upscale for a nice uplift, anything in mind?

Yes, @rickysnit  , I think it would be a good preventive maintenance action to take.  As far as having anything in mind, no, I don't know much about that stuff.  I have been looking on line (including Partsconnexion) trying to find the value I need (400 v, 560 uf) with screw in terminals, but I cannot find anything matches.  I suppose I could do a mod to convert to snap-in or solder, but I really don't want to do that.  I plan on actually calling Partsconnexion on the phone next week to find out if I am missing something on their site. I guess I could also call Cary (sales department, because they no longer provide telephone tech support) to see if they will sell me the power caps by a telephone sales.  Their Mundorf signal caps re priced pretty high on their site, so I am sure I would take it up the wazoo if I bought the power caps from them, but at least I guess I would know I was getting replacements that would work.  I would hope.

@immatthewj  - Yeah, you can have filter caps fail becuase of something else down the chain.  Amps, because of the high amount of current, are particularly subject to all sorts of cascading failures.

The other way can happen as well. Bad filter caps can fry the rest of the amplifier, or the main power transformer.  Especially a bad thing with vintage amps that use transistors no longer made.