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Why I Rarely Re-Cap My Vintage Receivers

vinylisfinal said:
the capacitors of the late 1960's through the 1980's are well built. Capacitors either fail and don't work or they work. All repair books state this, as well as the instructor i had years ago.
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This is not true. Capacitance values as well as ESR can change dramatically as a capacitor ages. Such caps still work, but the changed values affect the circuit in ways not intended by the designer.

I've replaced many electrolytic caps that exceed 150% the labeled capacitance.
 
I never even knew it was possible for this to be debatable. I admit I don't spend as much time on the vintage end as I used to but one big reason for that is equipment failures do to aging components when I was running unrestored/non-recalled gear, particularly cap failure. Comparing this to $1000 cables is a logical fallacy if there ever was one, and a desperate argument. There are times when I disagree on this forum for personal reasons of taste in stuff, but this is just flat out BAD advice and if you're a fan of vintage gear I would think you wouldn't want to kill any more of it than necessary by suggesting that it be run into the ground.

Seriously, how is this even a debate?
 
kirk57 said:
This is not true. Capacitance values as well as ESR can change dramatically as a capacitor ages. Such caps still work, but the changed values affect the circuit in ways not intended by the designer.

I've replaced many electrolytic caps that exceed 150% the labeled capacitance.
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Very true! It's mostly a trick of the math, but when the esr goes to heck the series capacitance value can look good or even too good. That's why an esr meter is more valuable than a C-only meter.

As soon as the esr (I prefer dissipation factor) starts to rise it's time to get that cap out of there.

I disagree that manufacturers provide useful guidance on lifetime. They provide a life typically defined as 2X the dissipation factor running at full ripple current and max temperature. Extrapolating that for the conditions most audio caps run under is near to impossible. Thus periodic measurement is more useful than blanket recommendations to replace after xx years. That misses all the ones going bad sooner and replaces a lot of parts that haven't changed by much at all.
 
I recap for reliability's sake. I do notice a slight sonic difference (for the better imho), but it is so small, I wouldn't do it just for that. My DH-101, DH-200, DH-500, PAT-4, Pioneer SX-580, and a SX-450 all had old, but decent caps. The rubber plug was cracked on all of them (YES, ALL of them) and there was a little ring on electrolyte on the pcb.

So in vintage gear, I replace them so they don't cause issues.
 
All this discussion makes me wonder why, if capacitors do not degrade in amplifiers, that they do in speakers? Logically, I think that in both applications, they are both degrading after a long period of time. In speakers it is very audible, I remember doing the capacitor change in my IMF's and what a difference it made. Plus, now I know those capacitors are good and they won't take out a valuable driver from busting open or something. I had a lot of people warn me against changing the capacitors because it would make them sound worse, but they actually sounded much better.

I don't know if the same theory applies, but I would think in some ways it does in amplifiers and receivers.
 
I am in complete agreement with EchoWars, if you use the google search, it will bring up probably a hundred threads dedicated to whether to recap or not. I think any cap more than 20 years old is past its prime but thats just my opinion.
 
hauf888 said:
Some of you may know that I have a weakness for vintage stereo receivers, particularly Technics, Sony, Pioneer and Kenwood....In all I have over sixty units now, most in various states of disrepair...Perhaps fifteen are running now and I cycle them through and "blow the carburetor" out on all of them once in awhile to keep em thumpin. What I rarely do, however is recap. And I should add the average age of my typical receiver is approaching 40 years of age.

I don't recap for several reasons...First, I am a firm believer in the synergy of having all components mature together. I remember about five years ago I came into a beautiful Sony STR-6036A, an amazing unit whose output far exceeded the sticker 15 watts. Anyway, I had joined another forum and the consensus seemed to be that anything and everything should be recapped willy nilly if over thirty years old...wow! How exciting! I was gonna have a chance to have at all my gear and recap til the cows came home. I started with the Sony....my beautiful classic Sony. I gathered the caps and one fine day I popped on my apron, wielded the desoldering iron and, in three hours, changed out every electrolytic on the boards...

Sadly, when I brought the unit up slowly on the variac I was shocked at how the tone had changed! About 20% of the midrange just disappeared! I could have cried...hell, I think I did cry! And you know the saddest part is that there was nothing wrong with the caps I changed out...not a one of them...Sony used great stuff and those were the days when caps were quality, quality, quality.

You know my bottom line is that electronic gear acquires an audio patina just like fine furniture, beautiful coins, and antiques in general....Finagling with replacing components just because they may have some age is just senseless...look at them first...really look at them...I can guarantee you that 95% + of them will look great, if not all...

My Sony never sounded the same again but I never had another recap festival again..and all my equipment has held up beautifully! Just because you have a nice piece of vintage gear does not mean it should be recapped....the old saying that to a man with a hammer, everything looks like a nail, is very appropriate here...to an audiophile with the recapping urge, everything looks like a chance to use the desoldering and soldering iron...I encourage you to resist the urge...once the patina of sound is gone, it can not be brought back...
In closing I should mention that I have done plenty of repair jobs for people who recapped units only to have trimmed leads carelessly fall down into the unit and short out components on the board...be careful, use a variac, and check after every changeout...you won't have the woe is me..what did I do wrong regrets...

Just my two cents....love to hear yours and Happy New Year!

Rosie :music:
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I agree. Some like to tinker. I don't. I like to listen.
 
Greetings Rosie and welcome to AK. I am a compulsive recapper. But I enjoyed your post. I have a nice Pioneer waiting for a recap. I think I am going to fix the lights, clean the switches and controls and have a listen. Maybe I will enjoy aural patina. If I get too nervous I will work on the power supply.
 
Thanks guys..loving the posts...sorry to the old hands but some of us have not been around the club for ten years...this is new to alot of us so thanks for your understanding....I didn't mean to hit the bees nest and I have learned alot just from this thread...the more inpu the merrier and thanks again


Roie
 
i'm thinking the op should send out one of those tired old units to one of the great techs that have already commented in this thread. Then you'll have a point of reference of which to make your comparisons by. Obviously the piece of gear that you recapped you didn't do correctly. I consider myself lucky to have pieces recapped by both gentlemen and let me tell you the difference is nothing short of astounding. A HUGE upgrade!

But it's also a free county; if you'd like to keep your tired old piece and you're happy with it then carry on. Another thing to consider on these old unrestored units......would you leave them on while you casually run some errands for an hour or so:scratch2: I know I'm not a big fan of fires especially when they're in my home.
 
I love vintage gears and I find this thread very interesting.
There are talking about different caps give different SQ and there are reports saying on ABX tests, the X tests usually show no-one can be sure or identify any cap is superior than the rest! Our choice to believe either one. I lean towards the latter.
I agree that caps do aging. So the amp is not performing what it was designed after 20+ years. Whether you like these aged cap sound is your taste. period.
For me, I change gears, so before I let go one, I tend to recap the vintage as 1 alternative - hoping it to gain back the shelf placement.
I may put back the original caps as 100% originals have higher selling value in Hong Kong.
 
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I should cut and paste in my standard response to recapping, but I'm using my wife's Christmas present tablet to type this. Suffice to say, I've got a turntable and a power amp working just by recapping. Sure, I could have spent time and/or money buying a service manual (none online), peering at the circuit diagram to see where the feedback loop is, and pulling out and testing suspect caps until I found the bad one. But a recap on all the small signal caps was less than $15, and while it was in pieces, I did the main caps as well.

Lee.
 
Electrolytic caps fail by design. Age eats them up. There is no other way about it. A 30 year old electrolytic has either failed, or is getting ready to fail.

It's kinda like folks running 20 year old tires. Sure there is plenty of tread on them, but they are hard as rocks and have no traction.
 
It's entirely possible that caps in speakers age faster. Almost all caps in amps and receivers see very little ripple current. In speakers their main job is to conduct ripple current- the music itself to the drivers. Worse, those caps are usually non-polar electrolytics, often low grade ones because the selection is so limited. I prefer to use films, but you have to be a bit careful as that can change the voicing quite noticeably, so a bit of adjustment and listening is often needed.
 
hauf888 said:
Some of you may know that I have a weakness for vintage stereo receivers, particularly Technics, Sony, Pioneer and Kenwood....In all I have over sixty units now, most in various states of disrepair...Perhaps fifteen are running now and I cycle them through and "blow the carburetor" out on all of them once in awhile to keep em thumpin. What I rarely do, however is recap. And I should add the average age of my typical receiver is approaching 40 years of age.

I don't recap for several reasons...First, I am a firm believer in the synergy of having all components mature together. I remember about five years ago I came into a beautiful Sony STR-6036A, an amazing unit whose output far exceeded the sticker 15 watts. Anyway, I had joined another forum and the consensus seemed to be that anything and everything should be recapped willy nilly if over thirty years old...wow! How exciting! I was gonna have a chance to have at all my gear and recap til the cows came home. I started with the Sony....my beautiful classic Sony. I gathered the caps and one fine day I popped on my apron, wielded the desoldering iron and, in three hours, changed out every electrolytic on the boards...

Sadly, when I brought the unit up slowly on the variac I was shocked at how the tone had changed! About 20% of the midrange just disappeared! I could have cried...hell, I think I did cry! And you know the saddest part is that there was nothing wrong with the caps I changed out...not a one of them...Sony used great stuff and those were the days when caps were quality, quality, quality.

You know my bottom line is that electronic gear acquires an audio patina just like fine furniture, beautiful coins, and antiques in general....Finagling with replacing components just because they may have some age is just senseless...look at them first...really look at them...I can guarantee you that 95% + of them will look great, if not all...

My Sony never sounded the same again but I never had another recap festival again..and all my equipment has held up beautifully! Just because you have a nice piece of vintage gear does not mean it should be recapped....the old saying that to a man with a hammer, everything looks like a nail, is very appropriate here...to an audiophile with the recapping urge, everything looks like a chance to use the desoldering and soldering iron...I encourage you to resist the urge...once the patina of sound is gone, it can not be brought back...
In closing I should mention that I have done plenty of repair jobs for people who recapped units only to have trimmed leads carelessly fall down into the unit and short out components on the board...be careful, use a variac, and check after every changeout...you won't have the woe is me..what did I do wrong regrets...

Just my two cents....love to hear yours and Happy New Year!

Rosie :music:
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I have to agree. I'm the guy who says "if it's not broken don't fix it".
There is only one unit I may have re-capped someday and that's my Sansui 8080db, but only when it develops a problem and not before then. My tech is very good with vintage gear anyway and tries to get as close to original specs as possible with parts and doesn't use questionable quality parts (he's kind of picky that way), so I would trust him to do it.
 
I remember when all the Japanese transistor gear hit the US market. The "high end" guys complained about it mostly sounding "tinny" and "harsh."

Let's presume that that judgment was based on new gear with new, fresh electrolytic capacitors. Recapping might just recapture those same qualities.

I've got a Marantz 1060 integrated amp coming back from the shop Monday. I had Norm replace the power supply caps and the output coupling caps. He also checked the internal coupling caps - I ask how many and which ones he replaced there.

This amp always had a reputation for being smooth and warm. We'll see how that changed shortly.

I've also had Mike (our host over under "Tuners") recap several tuners for me, as well as concurrent realignment and checkout and sometimes upgrades too. I've been very happy with the improved sound his efforts have produced.
 
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This is interesting to me. I largely dwell in the realm of tube gear, and you will very seldom find a tube guy who doesn't say re-cap it. That includes a lot of non-electrolytics as well. In tube gear, its considered an absolute necessity to replace the capacitors because it blows things up when they fail. In solid state gear, suddenly its the magic of aged capacitors creating the sound that is desirable.

dunno, I have non-audio equipment that I have re-capped out of necessity. I've done "scorched earth" rebuilds on radio equipment and other things that involved replacing every single capacitor in the unit. None of these performed worse afterward, and in almost every case it was a significant improvement in performance and reliability afterward. Theres nothing quite like switching on a 30 year old bit of radio gear and having it work absolutely flawlessly with no funny quirks due to failing parts. In a more related area, I have fixed speed stability problems on direct drive turntables by re-capping them.
 
This is all very interesting. I bought a JVC A-X5 amp last summer. The previous owner had it checked by his tech, and only replaced a relay. It sounds great. I bought a 2nd A-X5 amp that had all new caps, thinking it would sound much better than the first one. The person who did the recap stated it was just about on par with his A-X9.

Well I was very disappointed. The first one was much warmer, louder, had much deeper base and so on. On the 2nd one, I figured the caps maybe needed a burn in time and left it on for 8 or 9 days. Still the same.
I sold it and kept the first one. I guess the new caps did really change the sound for the worse. Don't get me wrong, it did sound very nice, but not as nice as the first one.

Glenn
 
Why do the capacitor manufactures specify a "Load Life"?

This can't be a sales gimmick designed just to sell more caps.
 
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