Audio Grade Capacitors. Marketing Bull? - Page 1
Forum section: electronics / beginners

author: andrewkirkby
author_rank: Contributor
timestamp: May 28, 2013, 06:58:37 pm
content: I pretty much asked the question in the subject.I'm replacing 2 x 10,000 uF 63V Capacitors in my old home cinema amplifier. It's showing signs of psu issues and those look to be the culprit.My question is, are the 'audio' grade caps really much different to standard ones? I can easily obtain that value of electrolytic from mail order suppliers here in the UK but can't find anything specifically designed for 'audio' use.I am a sound engineer by trade and I do care about the sound quality out the back but there's a lot of marketing wank out there and want to be sure before I pay more to import something or go further afield..The ones in it are Samwha branded and it's a Denon amp.

author: madires
author_rank: Super Contributor
timestamp: May 28, 2013, 07:25:04 pm
content: You don't need to fail for audiophoolery caps :-) Standard caps from well known vendors are fine.

author: Lightages
author_rank: Unknown
timestamp: May 28, 2013, 07:34:19 pm
content: There are some arguments for certain types of capacitors to be used in the signal path of some amplifiers. For a power supply there is no argument for any "audio" grade capacitor. Use a capacitor that has a voltage rating of at least 30% more voltage than it will handle and, for a power supply, a low ESR type could be advantageous.

author: senso
author_rank: Frequent Contributor
timestamp: May 28, 2013, 07:35:25 pm
content: Fit some sweet Panasonics in there.

author: andrewkirkby
author_rank: Contributor
timestamp: May 28, 2013, 08:10:21 pm
content: Yeah RS do panasonic caps of that value for £3.50 each.The ones I'm replacing are labelled 63WV 10,000 uF. What's the W?Also 'DL 85degC (M) Guess that's the model and heat tolerance..

author: daveshah
author_rank: Unknown
timestamp: May 28, 2013, 08:30:47 pm
content: WV probably stands for working voltage

author: dr_p
author_rank: Frequent Contributor
timestamp: May 28, 2013, 08:31:00 pm
content: Working Volts

author: ConKbot
author_rank: Super Contributor
timestamp: May 28, 2013, 08:35:10 pm
content: Quote from: andrewkirkby on May 28, 2013, 08:10:21 pm"WV" is generally "working volts" or "working voltage" I.e. the caps will have a surge rating thats somewhat higher than the working rating, but can only handle 63v at the rated temp at the rated ripple etc. to get the rated lifetime spec.

author: andrewkirkby
author_rank: Contributor
timestamp: May 28, 2013, 08:51:03 pm
content: Gotcha.. So surpass that rating by a factor of ? and you can substitute in a standard cap just fine.

author: mariush
author_rank: Super Contributor
timestamp: May 28, 2013, 08:56:28 pm
content: Measure the diameter and determine how the capacitor is connected to the board (normal leads, screw types etc). Then try to get 10000 uF 80v, if you can't find any matching requirements i mentioned, use 63v capacitors. If you still can't find, you could probably go down to 8200uF (or other values closer to 10000 if they exist) but you may have problems getting the maximum voltage out of your amplifier in that case (or get distortion at high volumes)

author: JuKu
author_rank: Frequent Contributor
timestamp: May 29, 2013, 07:45:36 pm
content: Yes, they are special (kind of). Their internal resistance (ESR) is significantly smaller over the audio band, and in some circuits, that might have an effect. On the other hand, quality capacitors made today are better than some years ago. (Sadly, crappy parts are much crappier.) Besides, if the choice is between an amp that does not work at all and an amp tbat does not sound quite as good as ot dos as new...

author: andrewkirkby
author_rank: Contributor
timestamp: May 29, 2013, 11:43:19 pm
content: As an Audio Engineer, I'm far more of the opinion that better or equal to what it was is the only route. I hadn't taken esr into account though. Makes sense.Maybe as an experiment i'll buy some decent ones as a one off test, a set of panasonics that are standard parts and a set of crap ones to see what the difference in performance is. I can plot the difference using pink noise and Smaart live which compares the input with the output and plots the result.I think it's time to look at some data sheets too...

author: Excavatoree
author_rank: Frequent Contributor
timestamp: May 30, 2013, 12:13:06 am
content: Quote from: senso on May 28, 2013, 07:35:25 pmRubicons are sweet. Panasonics add a delicate crispness to the sound, with a hint of a rosy glow.

author: Bored@Work
author_rank: Super Contributor
timestamp: May 30, 2013, 04:53:45 am
content: Quote from: Excavatoree on May 30, 2013, 12:13:06 amNothing beats the softness and warmth of the sound of a Chemicon going pop

author: JuKu
author_rank: Frequent Contributor
timestamp: May 30, 2013, 05:24:52 am
content: Quote from: andrewkirkby on May 29, 2013, 11:43:19 pmThat won't show a difference. If you have an Ap, look at impulse response, distortion vs frequency and IM. You might see someting with a scope and square wave at 50% power and above.