Why I Rarely Re-Cap My Vintage Receivers
- Thread starter hauf888
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Gang-Twanger
Resident Wharfedaliophool
I can't help but wonder when recappers use brand-new poly caps (or whatever) on vintage gear and then talk about the sound being as intended. How can someone say that unless they recap with the same exact N.O.S. cap-type/brand from that same era? A lot of people seem to agree that not all caps are equal. Anyway, just sayin'. Perhaps it doesn't make a noticable difference with amps/receivers from the late '70's and newer, but I have to wonder about early solid-state gear and tube amps.
Anyway, I don't know enough about this stuff to really say one way or the other... I'm just speculating here (But as I said, I HAVE noticed a clear difference when using different caps in guitar gear... With that stuff, it seems pretty-cut-and-dry). I'll know a lot more once I redo the recap on my W90's. I want to put N.O.S. oil caps in them (They were recapped about two years ago and then barely used until I got 'em). If they suddenly get better, then I'll know, but I can see there being a difference in a 50 year old speaker that originally came equipped with oil caps. Perhaps it's a much-finer line with more-modern gear from the '70's and '80's, but my speakers were designed to use dinosaur parts.
Anyway, I don't know enough about this stuff to really say one way or the other... I'm just speculating here (But as I said, I HAVE noticed a clear difference when using different caps in guitar gear... With that stuff, it seems pretty-cut-and-dry). I'll know a lot more once I redo the recap on my W90's. I want to put N.O.S. oil caps in them (They were recapped about two years ago and then barely used until I got 'em). If they suddenly get better, then I'll know, but I can see there being a difference in a 50 year old speaker that originally came equipped with oil caps. Perhaps it's a much-finer line with more-modern gear from the '70's and '80's, but my speakers were designed to use dinosaur parts.
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ConradH
Lunatic Member
Ah, the old cap argument again (pun intended). I firmly believe that bad caps should be changed and good caps should be kept. Measured for both value and loss, you can predict if a cap will go bad anytime in the near future. IMO, there are a lot of bad caps out there that people don't realize are bad because the sound hasn't changed much, or they've slowly gotten used to it. OTOH, nothing good happens when you replace a good cap with a long history of reliability, with a new cap having zero history. Every hear of infant mortality of components? Ever look at the DC leakage of old vs. new parts? I won't dare advance the theory that as we get older we're more easily annoyed by certain sounds, and a "mellow" sounding receiver or amp is just better to us. Oops.
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If I get around to changing the fabric over the speaker, I'll take one. I found some cool silk fabric that has angels playing harps that I think will look nice in it.
My theory is that value drift on some older units can create a..."unique" sound for better or worse.
After my recap I'd say it was like the sound was tamed and disciplined...for the better; bass was less boomy and more accurate and focused in the soundstage. Before it was louder and seemed to be everywhere but not "worse".
Granted, if you replaced everything with dollar store caps or screwed up a joint....maybe that's what happened....check your solder joints to make sure you didn't kill the midrange(I've managed to kill the bass by bad soldering before) by connecting two solder joints together by accident or maybe a channel wire came loose when opening it up.
After my recap I'd say it was like the sound was tamed and disciplined...for the better; bass was less boomy and more accurate and focused in the soundstage. Before it was louder and seemed to be everywhere but not "worse".
Granted, if you replaced everything with dollar store caps or screwed up a joint....maybe that's what happened....check your solder joints to make sure you didn't kill the midrange(I've managed to kill the bass by bad soldering before) by connecting two solder joints together by accident or maybe a channel wire came loose when opening it up.
shacky
Addicted Member
I disagree. Capacitors can often drift in value and increase in ESR as they age, however they will continue to 'work' in the circuit. Accordingly, the equipment, whilst still functional, will not performing as designed. Assuming that a capacitor is working fine unless it has leaked, exploded or shorted out is incorrect.
I can completely understand why some people are shocked at the sound post-recap, but all you're hearing is the sound of the equipment as originally designed. We get used to the warmer, woolier sound, with somewhat subdued treble and the resulting forward midrange. When the full sonic capabilities of the equipment are restored following the recap, the sound is no doubt different.
However, I'm a firm believer that the new capacitors aren't departing from what the designer originally intended back in the day. Circuit topology plays the predominant role in the sound of gear, not the capacitors.
If people prefer the sound of unrestored amps, then it's a personal choice.
Each to their own anyway - different strokes for different folks
I agree whole heartily :yes:
But I can understand the preference for your Sony pre recap.
Resistors (especially cheap carbon comps) can drift. Depending on the work I'm doing on a piece of tube gear, I might shotgun them with new parts just to make life easier. The issue with electrolytic capacitors is that they have a service life. 30 years is way beyond it. In other words, you're trying to compare apples to hand grenades.
As far as the "replace bad caps, keep good caps" line of thought, usually it's just a lot easier when doing that amount of work to replace all of them. If I have to take a cap off of a board, it's getting replaced unless I was stupid and forgot to order it.
Gang-Twanger
Resident Wharfedaliophool
"Sometimes it just gets tiring"..... That's funny.
pete_mac
Super Member
Capacitors age and their performance declines. They operate within their design parameters for a given time, and eventually start going downhill. This is science and fact - heck, the manufacturers provide this information. Many capacitors do not fail outright - they continue functioning but affect the frequency response and dynamics and accuracy of the equipment.
Capacitors are the known weak spot of vintage gear. In contrast, most resistors age pretty well, and a good tech will know which types of resistors age poorly and replace those during a restoration too. Likewise, transistors with known issues are selectively replaced. There's no point undertaking wholesale replacement of resistors and transistors for the heck of it, as they are generally not subject to the same lifespan issues as capacitors.
Yes, some capacitors age surprisingly well, but old capacitor is a 'dead man walking'.
Regarding topology, it is king when determining the sound of your gear. Have a look inside any piece of Japanese vintage audio from the 70s - they all use exactly the same Elnas or Nichicons, the same resistors, the same kinds of transistors. They sound different to each other due to the topology of the gear, not the brand/type of capacitor.
Each to their own. There are some superb cables out there which maximise the sonic performance of a decent system. That's what recapping is about too - getting the best sonics out of your system. Again, each to their own. One man's 'detailed' is another man 'bright', and one man's 'warm' is another man's 'coloured'. Personal preference comes to the fore.
pete_mac
Super Member
Capacitors aren't binary in nature. They do not work perfectly then suddenly cease working outright. They are like humans... they degrade with age. Some last longer than others, but they don't perform as well as they did when they were young.
Jesus H. Christ.
Have you ever seen the page where some people analyzed that photo and figured out not only where it was taken, but exactly when? Kinda cool, but OCD to the max.
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
Very interesting and a great point to boot .
Yes I have, and personally, I'd rather discuss that than this capacitor bullshit any day.
Allow me to respectfully state that you don't know what the **** you're talking about.
I would urge anyone to read through THIS THREAD before you spout off about something you don't know much about. Once you wade through all of that, you may find that posting here is redundant and unnecessary.