Good capacitors

Just get capacitors that meet the original spec, and you'll be fine.

Something like this might help you learn what's "important":

Have Fun! Rich

Well, I am pretty well up on capacitor theory, I am just looking for some particular brand name recommendations for these applications. I know that there's more to it than just V and C. There are about a hundred million different kinds of caps in the digi-key catalog; maybe someone here has tried some and has an opinion.

I should emphasize that these are all audio applications, so I want the cleanest possible power and the best filter performance.

Well, the tube amp, I just want that to work without catching fire. If someone knows a good source for replacement caps, I'd appreciate that too.

The big old caps for big old amplifiers were never cheap brand new. For the most part the bigger the cap the better. The lower the ESR the better. Look for low ESR caps. Multiple parallel caps are often better than one big one. Mid voltage types usually have better ESR fogures than low voltage types.

Replace with equal or higher voltage rating. Digi-Key should have Panasonics with low ESR.

greg

Try Farnell - they carry an even bigger range than DigiKey.

Caps is caps, unless it's audio, and then nothing makes sense.

John

It's yet another audiophool myth that 'capacitors have a sound'. ( excepting poorly applied electrolytics maybe )

Just buy a decent well-recognised brand for long-term reliability.

Graham

Some of those audio buffs say they can hear the difference between oil filled caps , BS.

Ceramics aren't microphonic? They "sound" like it to me! ;-)

I repair audio as a business (although I do other things as well) and I too do not agree with the "my 10,000 dollar power chord improves the sound of my amplifier" horseshit.

The only pair of ears I use when judging an amplifier is a scope and a signal injector. And an amplifier only sounds as good (or bad) as it's design.

The only thing an amplifier needs to be doing is increasing the amplitute of the input signal without coloration. The technology to do this below a level recognizable to the human ear has been around for decades. Why are people still chasing this ghost? Beats the shit out of me.

Your soon-to-be-replaced caps were chosen with certain varibles in mind and as long as your replacements meet the requirements you will be fine.

If what you are trying to get at by referring to "good caps" is quality related then Nichon makes a very nice cap true to it's values that won't run you a testicle to purchase. For power amplifiers I like to use the highest heat grade I can get (usually 125c). For filtering I never exceed double the value as it becomes more of a load then good. try and stay within or slightly higher working voltages.

As far as changing the originol "sound" I would only be concerned with how todays newer capacitor technology and lower ESR standards are going to actually "improve" the accuracy of the amplifier responce. At which point the old timers will shame you and banish you to Kracoland...

- Matt

Just realized my answer to your question was not entirely complete.

For mylars, films and discs I have no general preference. I like the Nichons for quality and longevity in electrolytic replacements.

If you do get any tube amps anything is better then the old wax caps I yank out of them all the time. Does that about cover what you were looking for?

- Matt

I'm working with mixers, synthesizers, and filters here, and while I'd normally agree with these opinions, it's been demonstrated, and I've personally observed, that a selection of caps with identical specs can give you a whole range of different sounds. The Roland TB303 is a great example of this; the sound evolved over time as parts cost and availability changed. Quite a few EQs and filters sound entirely different when you swap caps out, even after the sound has been recorded and compressed to MP3.

I personally don't believe that changing out filter caps in your tube amp's power supply will reveal some magical new tone, unless, as you've said, the ones originally installed were just crap. But I'm sure that changing the right capacitor in the right kind of circuit can make all the difference in the world. Process variables and manufacturing differences create all kinds of nonlinearities, and some are certain to sound better than others.

I expect there's an entire subculture of cap swappers out there.. I am generally looking for maximum Q and/or minimum ESR, not so much a sound quality judgment, as obviously this depends more on the circuit than the brand of cap. However, I was hoping someone would have a little experience with the thousands of product lines out there. Unfortunately all of my documentation from the 80s refers to parts that haven't been made for a long, long time.

I know a while back there was a thread about replacing computer motherboard caps; I noticed in CompUSA the other day that they were promoting some new motherboards with "premium quality Japanese capacitors." It sounds like baloney, but apparently quite a few posters here have revived dead mobos just by replacing the power supply caps.

It's not baloney. The reason is because a few years back there was some manufacturer that royally screwed up their caps, and millions of them ended up in motherboards before they started popping their tops and the problem came to light.

The values used typically like low-K 22pF certainly don't affect the signal path in any way I've ever come across.

You're a idiot if you use ceramics for large values. Plastic film is invariably used for > ~ 470p IME

Graham

Utter non-scientific bollocks.

This is the kind of nonsensical thinking crap that's resulting in certain ppl now once again claiming the world was indeed made by God - our ( the white anglo-saxon God note ) in seven days.

Graham

It's funny how the freaks use the example of a defectively manufactures batch of caps 'proof' that they must have a 'sound' in an entirely different application.

Graham

Actually, what I was hoping would happen is that someone would say, "yeah, those ____ caps were total crap, and they're a little better now but I always use ____ caps instead because they last ten times as long," but your reply was probably helpful too. Or at least entertaining. Well, at least I know I'm not alone anyway.

The *brand* of capacitor certainly has no effect in any case. You need to consider the technology.

You're a f****it to believe so.

I guess you didn't ever learn about the capacitor equation ?

Graham

Did you ever wonder why, in spite of the pages and pages of equations available on the web and in physics textbooks, cap manufacturers still insist on graphing impedance on their datasheets, and why no two graphs seem to look the same?

Take a look at a few SPICE models of capacitors and come back when you think you know the answer.

These guys will build whatever you want, if mere plebeian standard devices are not good for you:

I actually got some EHT caps made by them; excellent business to be in: a couple of owner-managers, a small specialised production with generous margins. No stress ... No stockholders ...

PS:

They obviously have found a rich vein in the, let's be kind, "audio enthusiast market". But, to be fair, their products are really good.