What type of caps should I use - Page 1
Forum section: electronics / beginners

author: patra710
author_rank: Newbie
timestamp: September 12, 2013, 01:25:06 am
content: Hi, I am recapping an old pioneer amp. I have read that different type of caps have different affects in audio circuits and power circuits. I am not sure what brand or series to get. Some advice would be very welcome. THANKS

author: Psi
author_rank: Super Contributor
timestamp: September 12, 2013, 01:33:36 am
content: It entirely depends on the type of cap your removing.

author: AndyC_772
author_rank: Super Contributor
timestamp: September 12, 2013, 06:38:27 am
content: The best advice I can give would be to learn electronics from almost anywhereexceptaudio forums.If you're swapping out electrolytic capacitors from a power supply or audio amplifier, you won't go far wrong if you pick one of the reputable Japanese brands: Panasonic, Nichicon, Rubycon, Nippon Chemi-Con or Sanyo.Choose a family with as long a rated lifetime as you reasonably can, and with a temperature rating of 105 deg C - even if the amp never runs anything like that hot, a cap rated for higher temperatures will last considerably longer.If you can, look up the spec of the original parts and choose a replacement with a similar ESR. If you can't find the original spec, then a "low ESR" replacement is likely to be OK, but avoid ultra-low ESR parts unless you know the circuit is designed for them (possibility of stability problems).

author: Rigby
author_rank: Super Contributor
timestamp: September 12, 2013, 04:26:27 pm
content: Quote from: AndyC_772 on September 12, 2013, 06:38:27 am

author: WarSim
author_rank: Frequent Contributor
timestamp: September 12, 2013, 06:04:35 pm
content: Quote from: Rigby on September 12, 2013, 04:26:27 pmI agree, allot if advice in the audio world is more about nostalgia and preference than requirement. There is also excellent knowledge about cap replacement knowledge out there in the audio electronics world but without detailed knowledge first it is very hard to tell the good info from the bad.I did not look up the era nor schematic of your amp. If all your caps are the currently available standard types it is you call if you want to investigate possible alterations. If you have now rare caps like oil and paper caps we need to know exactly where they are in cct. There are many options but all have a trade off and the wrong trade off in the wrong place will cause unwanted distortion.Lastly don't buy audio caps without investigating. I have seen people pay $30.00 for a repackaged $0.80 capacitors. This is where knowledge can save you money. There are special low noise audio caps out there but most people will not hear a difference. Are you one of the "golden ears" type?

author: olsenn
author_rank: Frequent Contributor
timestamp: September 12, 2013, 06:38:23 pm
content: Does brand of electrolytic really matter? I mean will the expensive Nichilon gold-series ones be any better than the cheapies I get off futurlec.com from China?

author: Excavatoree
author_rank: Frequent Contributor
timestamp: September 12, 2013, 07:14:17 pm
content: Quote from: olsenn on September 12, 2013, 06:38:23 pmYes. I took apart about 20 old Fluke meters. The Nichicon and Nippon Chemi Con capacitors were in good condition - no leaking, ESR good. The cheap, no name ones were all bad and had leaked electrolyte, damaging the circuit boards.There are at least hundreds, probably thousands of stories of crappy capacitors causing problems.

author: patra710
author_rank: Newbie
timestamp: September 12, 2013, 11:16:37 pm
content: Thanks guys, I will do some more research and hopefully come up with good choice. I have about 8 old pioneer and kenwood recivers that I want to recap. this advice will come in handy.

author: Fsck
author_rank: Super Contributor
timestamp: September 12, 2013, 11:43:51 pm
content: Quote from: olsenn on September 12, 2013, 06:38:23 pmif you need guaranteed performance/durability: yes - You're paying for a brand name that will hopefully stand behind their product and guarantee their caps meet or exceed their specifications.if you're just building random stuff that doesn't really matter (fun, disposable, etc): no - use whatever is cheap (or salvaged used components!)aka: for your amp, buy good quality caps. you don't really want to be replacing caps over and over again.

author: Psi
author_rank: Super Contributor
timestamp: September 13, 2013, 12:29:55 am
content: Also, If an electrolytic cap is part of the power supply section replace it with a low ESR 105+deg cap.You could replace all electrolytic caps with low esr versions but without knowing what they are used for there's a risk you will upset some circuits that may not expect such a low resistance cap.Modern ceramic caps are good for replacing generic stuff, but again - they have low esr which can be an issue with LDO linear powersupplies etcBe careful with tantalums, most are marked with a plus sign for polarity but others just have a black line. For tantalums the line means plus. (not minus like a electro cap)As others have said, brandname really does matter if you want the circuit to last more than 6 months. (Especially true for electrolytics, much more so than other caps.)That's not to say all unfamiliar brands are bad, just that there are LOTS of crap brands out there.

author: WarSim
author_rank: Frequent Contributor
timestamp: September 13, 2013, 12:50:01 am
content: Just a word of warning. All these suggestions are correct, but there are uncommon exceptions to these general rules of thumb. Here is the warning, some of these exceptions have the potential of catastrophic failure. That is why a definite answer is impossible without the details.So don't change specs by a significant amount without investigation. Because changing a capacitors type will change at least one spec significantly research before you try.

author: patra710
author_rank: Newbie
timestamp: September 13, 2013, 01:21:14 am
content: Thanks to everyone. I do have a degree in electronics from ITT Tech and have done some repair on electronic equipment but not that much. I got my degree at an old age and was at the top of my class but companies still went with the younger man. Can't blame them I guess. I do repair lcd TV's and I am looking for more experience in the field on my own, I what Dave on youtube along with others and read the blogs. I am still learning everyday. Thanks all

author: poorchava
author_rank: Super Contributor
timestamp: September 13, 2013, 09:36:42 am
content: One more thing: buy reputable brands only from reputable sellers (Farnell, RS, Digikey, Mouser, TME, or whatever else you have in your country). Ebay and other places like that are flooded with counterfeits, especially Rubycon and Nichicon.