Recapping Guidelines: Which Muse-type, Which Standard

Charivari... I agree this is still a grey area for me too.....

Perhaps I should have been more explicit and included wording something like " The original capacitance value should be used, unless you have fully considered the effect of a substitution on the circuit design you are working with."

(Those are just weasel words that say don't mess with the value unless you know what you are doing!)

It seems to be a fairly common practice to upsize the main output capacitors in an amp.... but I wouldn't have a clue myself where this approach could or could not be used in any given unit.
 
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Oh, nothing against your post, hpsenicka, it just seemed that the question I posed hadn't been covered yet and I simply used your 4 points to refresh the issue. Grey area? Nah, I'm utterly hopeless and wallowing in confusion about how cap sizes are changed almost haphazardly.

- JP
 
I deliberately avoided the subject "upgrades" or "mods" for a couple of reasons...

1) Getting some general consensus on basic assumptions would help establish a common foundation for discussion of more advanced topics... like why Brand X or Brand Y is better...

2) I suspect the issue of modding or upgrading by changing capacitor values is difficult to generalize, as a lot of it may be very dependent on the device you are working on. A separate thread may be worthwhile to get into that.

Another area that pustelniaker mentioned in his original posts, but hasn't been explored in much detail is what to do with other types of capacitors... most of the discussion has focused on electrolytic caps, and I would like to see similar discussion regarding replacement of other type, ceramic, mylar, film, etc...

...still lots for me to learn here!
 
Datasheet for nichicon MUSE

Thes are the only datasheets I can find on the muse caps..

KZ-: http://www.bc-2.com/test/nichicon/english/seihin/pdfs/e-kz.pdf

ES-: http://www.bc-2.com/test/nichicon/english/seihin/pdfs/e-es.pdf

FW-: http://www.nichicon-us.com/english/seihin/alm_mini/param_f.htm

FG-: http://www.bc-2.com/test/nichicon/english/seihin/pdfs/e-fg.pdf

OOPs-here's a diagram search for all of nichicon caps-: http://www.nichicon-us.com/english/seihin/alm_mini/daia_f.htm

and here's a list version--: http://www.nichicon-us.com/english/seihin/alm_mini/list_f.htm

This is about all I have ever come up with for MUSE.

Tal
 
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According to that dadta sheet for KZ series, the tan delta for nichicon KZ is lower than Panasonic FC's until about 100volts. In general about 0.02 less - will this make any noticeable difference music-wise?
 
1) In general, using a higher voltage rated replacement capacitor is a good idea (i.e. using a 50V instead of the original 35V capacitor)... provided that variations in physical package size (and possibly cost) do not create an issue.
Apparently there is a threshold where an increased voltage rating may not be a good thing. Electros are supposed to operate at some minimal percentage of their rating in order to keep character of the capacitor's construction. I am not going to cite the preferred %, in case I have not remembered it correctly. Jumping from 25 to 35 Volts would be well within the green zone.
2) Whenever possible use a replacement cap rated for higher ambient operating temperatures... i.e. 105C instead of 85C.
Provisionally, I would say 'yes', but as long as all the other specifics were coinciding with your needs. Of course, if the capacitor is especially subject to heat, as indeed they often are — especially in power supplies and tube gear — the higher rating would probably have priority over everything else.
3) Lower ESR is always better
If we really know what we are doing, I think that each cap would be chosen precisely for its specified characteristics. Get any comprehensive catalogue of electrolytics and notice how each manufacturer has a wide range of products. The relevant charts often have headings that illustrate the feature each series offers, such as long life, low DC leakage, low ESR, high ripple current, specifics for dielectric absorption etc. Sometimes these features are juggled to create smaller sizes and so on. Some series are undoubtedly attempts to combine as many of these desirable features as possible in one package. ‘General usage’ denotes the obvious. Price is an issue.

In order to make the best and most efficient choices, we would be very knowledgeable about the circuits we are working on. We might choose exactly the right capacitor for each location in the circuit. This possibility excludes me, because I am too inept at understanding circuits. My solution is to choose caps that roughly meet the more obvious demands. In digital circuits I want stability and low ESR. In power supplies I want low leakage, high ripple current, long life and often a high temp rating. Like that ....
4) Generally speaking, all replacement caps must have the same capacitance value as the original.
This is one of those old saws :deadhorse Some writers say that the original designers were not dumb, and the bulk costs of caps to manufactures is not the determining factor to the extent that performance is compromised for want of L. Still others seem to recommend beefing up power supplies and other sections as a matter of course. I take the weasel approach. I assume that the original design is adequate unless it is a famous fact known far and wide that it isn't. Then I try to find the best cap that I want to afford and will fit the space. For my needs, all the above stuff in #3 gets considered along with the fact that physical size (i.e. larger) is preferred. I am too ignorant to beef up values in some hope that it is better. There are some cases when it definitely isn't. It is easy to create stresses downstream unless you really understand your circuit.

That is as much as I can say without being flamed for being a moron. But I believe that everything I have said applies to common sense for the novice as it is informed by some 'basics'. For the more adept, modifying and altering circuits is part of the fascination of this hobby, mania or passion.
 
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Just finished my 1st re-capping project (got 5 more of the same model). This unit will not reveal the effects of new caps on the signal path, but it does yield some interesting info.

Here is the thread about the project: http://audiokarma.org/forums/showthread.php?t=51290

1. Some caps are a mother bear to get to.

2. The newer caps are significantly smaller than the old ones, when you get up from the minimum can size.

3. For smaller cap values, using better caps is not significantly more expensive than using caps matching original specs.

4. The unit I just did was manufactured in October of '78. I checked a few of the parts I took out. All of them I checked measured at or just below the original 20% spec for the parts (the low limit). For example, a 1 100µF cap measured 78µF.

More to come when I do my TX-9100 tuna...

Rich P
 
pustelniakr said:
4. The unit I just did was manufactured in October of '78. I checked a few of the parts I took out. All of them I checked measured at or just below the original 20% spec for the parts (the low limit). For example, a 1 100µF cap measured 78µF.

More to come when I do my TX-9100 tuna...

Rich P


Very interesting. I wonder if that is the result of di-electric leakage or if the di-electric material went dormant? I wonder if re-forming would bring them back to life. What make were the caps in your pioneer TT?
 
bigphil said:
Very interesting. I wonder if that is the result of di-electric leakage or if the di-electric material went dormant? I wonder if re-forming would bring them back to life. What make were the caps in your pioneer TT?

The original caps were as follows:

* Std. 'lytics were Nippon Chemicon SL series and Elna W series (both 20%, 85 degC). I replaced those with Panasonic FC series and Nichicon PW series (both low ESR, low tan-theta, 105 degC).

* Non-polar 'lytics were Nippon Chemicon BP and Elna BP (std. 85 degC). I replaced with Panasonic SU series (85degC 20%)

My guess on capacitance drop would be drying of the dielectric. I'm surprised to see that they all remained so close to being in spec after 27 years.

Rich P
 
Think a TT would be the 'best case' on the old cap values. On average, considerably less play time and very little heat compared to a power amp, etc.

Do you have the equipment to align your tuner? Will be interesting to read about the results with it.
 
Yamaha B-2 said:
Think a TT would be the 'best case' on the old cap values. On average, considerably less play time and very little heat compared to a power amp, etc.

Do you have the equipment to align your tuner? Will be interesting to read about the results with it.

The power supply has 3 'lytics, on the order of 470µF, 25v & 50v very near to the heatsinks for the pass transistors, but the sinks were selected for longevity (they do not get significantly warm). The caps near it are now all long-life, low ESR, low tan-theta, 105degC, parts now (good for another 30 yrs?). I specifically tested the original parts from that area and all were, as I stated, either within the 20% low limit, or just below, so the heat, if any, made no significant difference to longevity.

I do have some real nice equipment for tuna alignment. I'll post a step-wise DIY for that sweetening project, posting separation, IM distortion, THD, selectivity, sensitivity, etc. (before and after recapping).

I must say I am a bit intimidated but "Damn the torpedoes! Full speed ahead!"

Rich P
 
I am going to tack this on to the end of this thread so it will give you all something to think about.I have been a tech all my life and have been repairing all types of electronic equipment.I am now retired but I did own my own business restoring vintage equipment well beyond the audio field.First I would not put larger caps in the audio circuit.Here is the reason. ALL Caps store energy "voltage" Large caps will tend to slow down the signal path and that is called distortion. Designers try and design with the least delay or capacitance that is possible. If you are upgrading a vintage amp and it is your dream amp and you are going to keep it for ten years then it may be worth recapping it. I would use a good off the shelf replacement.Just remember that when you look under the hood of you 1977 receiver and see 100 caps only about 20 of those caps are in the signal path for BOTH channels. I believe that, lead dress,parts placement and soldering can have huge effects on finished results.Long leads are to be avoided at all costs.Low end amps have all the above problem, high end amps go to extremes to try and avoid them.Here is a lesson I learned .For years I rebuilt Vintage Jukebox amps. I could really improve the sound of these old jukeboxes but people didn't like the new cleaner sound they wanted the old bar room sound.All the above applies to the audio path only.
Ed
 
EddyR wrote

I have been a tech all my life and have been repairing all types of electronic equipment. I am now retired but I did own my own business restoring vintage equipment ....
I will be looking around for other things that you may post or have already written. There are a couple of things I would like to comment on (and maybe you will want to respond?):
I believe that, lead dress, parts placement and soldering can have huge effects on finished results. Long leads are to be avoided at all costs.
Do you mean wire leads or capacitor leads — or both. Modern caps are often smaller than the originals. It means forming the leads in such a way that the cap does not necessarily sit flush on the board. In order to ensure that the seal is not broken at the base of the cap, application guidelines direct installers to start the formation at a specified distance away from the base plug — e.g. 2 m.m. before the elbow. As a consequence, the leads are going to be a little longer, but not by much.

Soldering seems to be overlooked in importance, although there are some good tutorials on the web. I have worked on soldering for a long time, but I still consider myself a student. One writer recently said that soldering is more of an art than a mere skill. My current bear are IC pins on the square type pads. On vintage gear it might be binding posts which soak up heat at the same time the solder at the post's base is melting. In virtually every project there seem to be a host of nagging little doubts and questions related to soldering. I will always welcome tips and info from long-time pro's in regards to soldering.

Dressing wire is another issue I still have trouble with: neatness usually seems to defeat the efforts to keep the length of the wire as short as possible. — Lorne
 
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Recent Paper on Capacitors

Some time ago on this thread I indicated that a paper was about to be published on the web in regards to capacitors. It is now up for viewing. It is entitled "Capacitor Characteristics" and dated September 24, 2005:

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

The author is Rod Elliott of Rod Elliott Sound Products in Australia. He is no stranger to controversy. In the past he has challenged a core of opinion among many DIY audiophiles in regards to claims that some specific qualities in caps determine the sonic output of audio circuits. Rod challenges the 'magic part' theory. The paper makes for lively and interesting reading. His conclusions are based on a series of experiements and measurable observations.

I am not proffering an argument one way or another here. Any discussion in regards to this new article might be better presented in another thread. But I will recommend it to all those AK members who have found this thread of interest. It's a twenty page print-out. So warm up the ink jet/lasers and print off a bundle to pore over in a hot bath — my favorite place to read. :D — Lorne
 
I've read the Rod Elliott article, always liked his site. I think the main premise of his article is the amount of inductance in a cap. That can cause a sort of crossover frequency. Bypassing is the cheaper way to go than buying BG caps for the most part. A good experiment would be to take some kind of audio equipment, replace the last capacitor in the audio path before the RCA outputs and listen and then try others. You will hear more difference in changing values at this point than you would brands. Of course, doing the entire signal path may change it more. I generally put in larger caps in the decoupling and try to stay close to stock in the signal path areas. I've replaced the same cap 2-3 times or more to get the sound I wanted, mostly in this last cap before the outputs. To be on the safe side, replace all with the same values and you can't go wrong. Remeber though, some manufacturers had to cut corners to save money, thus used smaller or cheaper caps, enough to "get by."
 
Lorne I read the article that you added to your reply.That person knows a lot more about caps than I do. Near the end of his article he gives a good picture and review of a bad cap replacement.If I had to replace that cap with the oversize one I would have stood it on end and then there would only be one long lead not two. He's correct about long leads on parts.I worked on tube radios and amps for many years and all wiring is critical to good clean operation. Here in the DIY section I have seen pictures of beautiful home built amps but some of them had very long leads on components to make them look pleasing. I was amazed how poorly one of my high end amps was wired.I know the builder as we both fly model aircraft. He replaced it with a hand built one for me. I have one big receiver that uses very small wiring from the outputs and then uses very small pinch connectors on the back panel. Thats like a fireman trying to put out a big fire with a garden hose. I think vintage is a great hobby but it can become a obsession.Ask me how I know.
Ed
 
While another article with data to distill, I will continue to be guided by my ears when it comes to things audio.
 
Hey, great article. I don't pretend to understand most of it but some good info there. "Keep cap leads short," as EddyR pointed out.

Murray
 
I've been studying this issue for some time but have yet to undertake a major re-cap project. Here are my theories and plans but they haven't been field tested yet:

Power Supply:

The big power source caps are usually space constrained or have mounting issues so I'd leave them as-is unless one sees or hears evidence of degradation. If necessary, I'd replace them with one size larger but would bypass them with a film. The reasoning is that bigger is slower - that's the thinking at Audio Research where their new gear uses several smaller power caps rather than one big one. Slightly bigger does give one more energy storage for the power amps. The bypass film cap is "faster" too and fills in the ripple gaps although many designs will put a local electrolytic cap of say 100 microF on the local boards across the rails - replacing and bypassing these may be more useful for the signal boards.

A related improvement in the power supply is replacement of the rectifier diodes with the soft recovery type. That sends less grudge and ringing into the power supply caps, thereby lowering the demands on the caps.

Coupling Caps:

These tend to be small electrolytics that can be usefully upgraded with big films - polypropylene or styrene preferred. If you find a tantalum in the signal path, like in the front or rear ends of a phono board, they are important targets since tantalums have such a poor reputation. Coupling caps are always in the signal path. I'd use the same capacitance as original.

For the tone controls, I'd give work here lower priority IF one has a bypass switch on the front panel (coupling caps still important).

Areas where I have no opinion yet is in the FM section (other than output coupling) and the RIAA circuits.

I've done a re-capping study on my Marantz 4300. This baby is so stuffed that physical dimensions of the replacement caps and accessablity become the driving issues. You can't just make a purchasing decision unless first you tear it apart to see what fits - working from the schematic alone won't get it done. I'm realizing that this machine is analogous to a thirty year old Ferrari V12 - beautiful if you can keep it working like new.

Frankly, I've seen little to convince me that the audiophile brands are more than marketing hooey - the type and material of the cap seems much more pertinent. Black Gate claims a novel electrolytic medium which could account for their popularity but so could mass self-delusion.

What I'd dream of doing is finding a quality vintage receiver with lots of room inside and separate boards and then using it as a test bed. Maybe someday - after I learn to solder. The last time I tried, I got a third degree burn on my hand that took 6 weeks to heal. Maybe I'll hire a college kid to do the physical work from my directions.
 
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Neosporin and bandaids. :D

"but so could mass self-delusion" In audio? Tell me it isn't so!

Murray
 
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