What's your thought about used components?

[acdc100]

Hello all

I'm building my audio power amplifier. Probably use TDA7294 or LM3886. Audio capacitors must be used to improve the sound quality. I searched web and found there're many used components (audio transistor pairs, audio capacitors and ICs) which are disassembly from old boards. The prices are much much cheaper than brand new stuffs. I'm thinking of buy these parts for my project since my budget is very limited. Does any one has experiences in using disassembly parts? are they reliable?

acdc

 

[thaumaturge]

Depends upon the part, why they were dissasembled and how old they are. Transformers I have no problems with. Transistors should be okay if certified not to be DOA. Caps you should get the date codes from before buying. Electrolytics dry out with age. I'd stick with caps no older than 5 years.
Doc

 

[4pyros]

Its like buying a used car you could always have problums down the road but thats about the same as a new car but you get a warranty with it.
Andy

 

[acdc100]

How about WIMA MPK capacitors? Most are more than 5 years

 

[thaumaturge]

Couldn't say as I'm totally unfamiliar with them. But the rule holds for electrolytics in general.
Doc

 

[TheLaw117]

Wima films aren't electrolytics. I recon they would be fine. Honestly, unless your layout is perfect, I think you'll have a hard time distinguishing a good quality Panasonic film from a pricey Wima. I use almost exclusively Wima (lol), but I don't think it really matters.

 

[acdc100]

I won't buy old electrolytics because it may dry out. Price is not so expensive. I just interest in MKP. I can't find any reason for the performance decrease with age for this type.

 

[acdc100]

TheLaw117, I agree..but WIMA looks cool, don't you think so? (-_*)

 

[thaumaturge]

Wow, a new market! Designer components!
Doc

 

[4pyros]

Wow, a new market! Designer components!

Don't laugh it's out there.

 

[jkuetemann]

I'd think most components would be fine, excepting electrolytic caps. I regularly pillage stuff out of old dead or retired equipment. Things like transformers, heat sinks, semiconductors (obviously these need basic functionality testing to be sure they aren't the reason the unit was scrapped in the first place) and other power components like higher wattage resistors, chokes and the like. Saves some $, keeps some of this stuff from the landfill. When the chassis and PCB is stripped I drop it off at the local transfer station for recycling. My , YMMV.

 

[diyroger]

I have a lot of old film caps (Wima, Rifa etc). They all work excellent. Also have some paired audio transistors (Sanken, Panasonic) and modules such as STK4191. Almost 100% works fine. My only suggestion on old parts is Never use old electrolytic caps! The performance is poor after years. You can't fine the problems with LRC meters but it's a nightmare for your audio system!