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Capacitors, capacitors.....

M

M1keC

New Member
I've recently re-cap'ed a few vintage hifi items and have been struck by a number of thoughts. Firstly, how do I choose not ony a capacitor manufacturer but also the series from the many that each manufacturer produces. Panasonic have at least a dozen different ranges, Nichicon 7 or 8. Even searching for audio grade still often gives a choice of several ranges for each manufacturer, sometimes at very different prices . Is there a guide anywhere as to which range is most suitable for specific applications? I did find a sort of guide for Nichicon's various series but it still left me to choose between 3 or 4 ranges that all seemed adequate. I don't really want to play twice as much for something that performs no better.
Then there is the whole question of ageing capacitors. I usually test the capacitors that I replace and 95% of them, even those approaching 50 years old, still test perfectly well. Did they really need to be replaced?
And if capacitors have a life then why don't manufacturers label them with the date of manufacture? If supermarkets can label their products with a "best before" date then surely capacitor manufacturers could date their products.
 
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M1keC said:
I've recently re-cap'ed a few vintage hifi items and have been struck by a number of thoughts. Firstly, how do I choose not ony a capacitor manufacturer but also the series from the many that each manufacturer produces. Panasonic have at least a dozen different ranges, Nichicon 7 or 8. Even searching for audio grade still often gives a choice of several ranges for each manufacturer, sometimes at very different prices . Is there a guide anywhere as to which range is most suitable for specific applications? I did find a sort of guide for Nichicon's various series but it still left me to choose between 3 or 4 ranges that all seemed adequate. I don't really want to play twice as much for something that performs no better.
Then there is the whole question of ageing capacitors. I usually test the capacitors that I replace and 95% of them, even those approaching 50 years old, still test perfectly well. Did they really need to be replaced?
And if capacitors have a life then why don't manufacturers label them with the date of manufacture? If supermarkets can label their products with a "best before" date then surely capacitor manufacturers could date their products.
Click to expand...

Wow... that's a litanny of questions there! But it does take a little science to match the capacitor specifically by voltage and capacitance. Usually it is marked on the capacitor to be replaced and makes for an easy match. Also don't forget polarity when dealing with electrolytics that have a (+) mark or bar on the positive charged side.

As for the various brands, there are charts that will cross reference these to a good match. I have found Mouser to provide the best information thus far. Some caps are made of particular materials, particularly when located near a heat source and its best to match these with same or similar materials :deal:.

Recently in a vintage rebuild, I removed a 1000uF, 25v cap and used the charge/discharge method with a DVM (digital voltage meter). You can find many a YouTube video on how to do this.. :dunno:it is pretty simple. Yet, not fully satisfied with the result, I then purchased a UA6013L, or Digital Capacitance Meter, from Amazon. Came rather quickly.. and I had heard of them but decided to splurge (old school term for spending money you don't have). Anyways.. at under $20, it didn't bankrupt me. :no:Hmmm.... back to the meter!? It takes an instant charge/discharge of the cap and then gives you the actual capacitance value. It will also call the cap out good/bad per the reading and has a rather large LCD screen. A plus for an aging senior.. :naughty:

Well, that's it! All I got on purchasing and testing.. hope it helps. In addition, if in doubt.. change the capacitor out. Most lower rated caps are inexpensive. The larger ones, not so much. However your biggest challenge will probably be removing it from the various circuit boards, some can be quite crowded and you have to take care not to heat damage other components in the same geography. Some of the soldering/desoldring can be a real pain :rant:

Good Luck :thumbsup:
 
once you have narrowed down the brand you want then I pick by color, well with some caveats about using power supply caps for power supply and audio caps for audio unless a film cap fits. Low leakage caps are either low leakage replacements or film which are extremely low leakage.

Roll on over to the main site for some of the manufacturers and see what they say the caps are for. A few of the makers have similar style sites. Here is one.

https://www.nichicon.co.jp/english/index.html>>miniature aluminum electrolytic>>check out those 50 different models in the list then click on the diagram to see what is better for different uses. You can see why the PW and HE are go tos for regular cap replacements.
 
M1keC said:
I usually test the capacitors that I replace and 95% of them, even those approaching 50 years old, still test perfectly well. Did they really need to be replaced?
Click to expand...
If we are just testing capacitance, yes, they will test correct or close but be really bad caps. ESR can change. The smaller the less it lasts according to ConradH a major contributor to the Capacitor Abyss thread here on ak. Give a few pages a read if you wanna be swamped with info.
 
I only purchase Nichicon or Yamaha as a rule. Physical size is sometimes a factor or the correct voltage.
OK to go up on voltage try to stay with the same uf's.

Capacitors will start to pass DC due to the material aging. Will still show correct uf on a test so don't trust IIRC.
 
I scoffed at the notion of replacing old eletrolytic caps until last week when I recapped my old preamp. I bought a kit from eBay so didn't choose the caps (they're all Nichicon, Nichicon Gold, Nichicon Muse anyway).
It's like several veils of grunge were removed between me and the record.
Recommended that you change old caps, electrolytic caps at least. Whether or not you need boutique caps is up to you.
 
Really, you only need to replace what's bad. BUT, if you intend on keeping what your working on long term, why not do a full recap while your in there, along with any other parts known to age poorly? I don't like having to go back in at a later date to replace more parts. I only do this if it's something I plan on keeping though. There is something to be said for preventative maintenance.
 
Data sheets. You have to read and compare the data sheets of each series from each vendor. And look for the qualities that are important for your application. This is the same work the original designers had to do, back when vendors and quality were very different.

for solid state work, the applications I often need caps for are:

high capacitance (over 1uF), low voltage (under 80VDC), audio path:

  • high capacitance means electrolytic is the only realistic option

  • Low DC leakage is best for audio frequencies, so that is why the Nichicon KL with 1/3 the normal ecap leakage is such a good choice

low capacitance (0.01uF to 1uF), low voltage (under 80VDC), audio path

  • with this range of capacitance, film caps have zero DC leakage, so a very good choice

  • the dielectric in the cap can make it even better for audio path, so metalized polyester or metalized polypropylene is best

very low capacitance (under 0.01uF), low voltage (under 80VDC), audio path

  • in this capacitance range, ceramic and mica are the two main, reasonable choices.

  • mica is expensive, but great for audio

  • ceramic (or modern version best as MLCC), is ok and the dielectric C0G NP0 is better for audio than the other dielectrics (e.g. XV7)
power path, not audio path

  • you’d like a low ESR (resistance turn nice power into less-nice heat, so lower Effective Series Resistance is best)

  • if you are early in the power supply, near any rectifiers, then you want the highest ripple current possible (to smooth the just-rectified-from-AC voltage) so these caps _smooth_ that rectifier ripple as much

  • low voltage(under 100VDC), low capacitance (under 5600 uF), radial

  • For me, the Nichicon PW, FW, HW fit these parameters nicely, but there are plenty of series choices here
 
Thanks to "shelter in place", I have spare time to recap a few components. Everything must be bought online, with home delivery (unless that is suspended due to the virus).

They're going into good quality units — Cary 2A3 power amp, Meitner preamp, Moscode Phono Preamp — and I'll go for good caps (Nichicon, Panasonic) rather than "no-name" caps.

All the caps I need are small and I only plan to replace electrolytics, of small values — e.g. no beer-can power supply caps. Also small cost (the biggest might be $8, and only a few of each, but maybe up to 20 caps in all, and most of them just 2 or 3 caps — the kind of order these suppliers hate. Thus I'll face the penalty costs for a small order.

And I'd like to buy everything from one place. I haven't bought from Mouser, Parts Express or any of the online suppliers mentioned here on AK before, this is all new to me — I used to get what I needed at nearby "stores" — remember those? I was surprised to see that Amazon has moved into this product area, and have some of things I need at a good price. I haven't prepared my whole list yet.

My experience level is very low, just so you know. I'm not a tech, have no training, in short an amateur. But I can solder well and can replace caps and resistors properly. Let's say I have a natural "aptitude", enhanced by reading 100's of tip here on AK over the years. I'm confident I can do these small jobs right, as all but one are straight replacements of equal value.

But ask me about what circuit design am I putting it into, and I won't have a clue. My only "analytic" tool is a mediocre DMM. And I have a good Variac.

Can you guys advise me where to shop? I want that part of it to be real easy, and it all arrives at my door, as my mobility is limited (back injury). If clarification is needed, I'll try to answer — but as I mentioned, I'm an amateur.
 
Well.. due to the virus circumstance, I am sure you will be able to get anything you want shipped to you now. Amazon CEO just announced this morning, he intends to hire an additional 10,000 delivery drivers nationwide. That's a lot of folk making sure anything you may need gets to you! Anyhow.. for audio hobbyists it will be a big deal. So no worries there :naughty:
 
I use a spreadsheet to research parts. Start with the parameters that you know about the part (unit, reference designator, values, etc), then add columns for each supplier. Enter availability (y/n), P/N, price, etc.

Now you can make informed decisions like: Can I get it all from the same vendor; Can I order enough from vendor A to get free shipping; What is the overall cost to move up to a higher grade for some parts; What is the O&S (order & ship) time; and so forth . . .
 
Mouser and Digikey are similarly priced mostly. I have seen some big differences but that is rare.

Digikey's site is slower to pull of the selections but you can get free shipping in the US/Canada by sending a check plus state tax as required which is nice. I order from both. I can mail a check today and receive goods on the same day as placing an order with Mouser today and picking less than fast shipping.

Overseas orders to Mouser seem to get free shipping when they reach 50 or 100 of something, €, £ or whatever. I feel like I'm subsidizing that free shipping as I can't get that from Mouser. Maybe they have warehouses overseas which can make business a bit cheaper to do but their parts prices are the same as here.


Parts Express is a speaker building supply house not an electronic parts supply house.
 
When repairing my JVC VR5535 I ordered lots of components besides the necessary transistors to justify the shipping cost from mouser.
Thought I would recap. But sounded good after replacing the bad trannies. To lazy to recap now. Just playing records and feeling a bit like a bad audiophile.
 
^^ Yeah, the gospel here at AK seems to be RECAP!! EVERYTHING!!! But somehow the damn things keep working, YEARS after everyone says they should be dead. Maybe they drifted out of spec, but still sound good, aren't leaking or swelling up. Maybe we're used to the "wrong" (out-of-spec) Sound, and replacing them sounds "worse".

But the idea that a cap failure can destroy other things is sobering. One of the things on my list is a DD turntable, a Denon DP80, with a couple of old chips — they can be replaced but only at great cost, so probably best to replace caps to protect them, there aren't lots of caps (I can also clean, relube and restore the motor).

I also have a Cary 2A3 Triode power amp that's one of the superstars of my system, but I blew one channel by inserting one power tube wrong, and it turned into a furnace — I was lucky, I only blew two caps (I think) and a resistor. I was able to identify them (I think) so I can get it singing again.

I'll draw up a list of all the caps I need (it's about half-complete now) and post it. As I wrote earlier, there's a wide range of values, but all small. I'm not doing anything fancy, not modifying or "upgrading" to pricey Boutique brands, but I will stick to the known good ones whenever possible.

You guys have been very helpful, and seeing the list may prompt some new ideas, so stay tuned... if you're still feeling helpful.
 
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I wonder how many wrecks out there are caused by fumbly soldering iron hacks like myself messing up perfectly good units doing the "necessary" recaps...
 
bimasta said:
^^ Yeah, the gospel here at AK seems to be RECAP!! EVERYTHING!!! But somehow the damn things keep working, YEARS after everyone says they should be dead. Maybe they drifted out of spec, but still sound good, aren't leaking or swelling up. Maybe we're used to the "wrong" (out-of-spec) Sound, and replacing them sounds "worse".

But the idea that a cap failure can destroy other things is sobering. One of the things on my list is a DD turntable, a Denon DP80, with a couple of old chips — they can be replaced but only at great cost, so probably best to replace caps to protect them, there aren't lots of caps (I can also clean, relube and restore the motor).

I also have a Cary 2A3 Triode power amp that's one of the superstars of my system, but I blew one channel by inserting one power tube wrong, and it turned into a furnace — I was lucky, I only blew two caps (I think) and a resistor. I was able to identify them (I think) so I can get it singing again.

I'll draw up a list of all the caps I need (it's about half-complete now) and post it. As I wrote earlier, there's a wide range of values, but all small. I'm not doing anything fancy, not modifying or "upgrading" to pricey Boutique brands, but I will stick to the known good ones whenever possible.

You guys have been very helpful, and seeing the list may prompt some new ideas, so stay tuned... if you're still feeling helpful.
Click to expand...

Just another addition, to the thought of replacing "all caps"... Perhaps that ideology should have been "quantified".. as based on the cost of the replacement cap :idea:
 
T68 said:
I wonder how many wrecks out there are caused by fumbly soldering iron hacks like myself messing up perfectly good units doing the "necessary" recaps...
Click to expand...

Agreed, I am in the middle of a (CV19 shelter-in) audio project, needing about 3 caps removed/replaced. It's advisable to use heat sinking clamps to remove the soldering irons high heat in/around other vulnerable components on the circuit board. If not, you are right, avoidable damage to wires and surrounding parts can happen :(
 
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