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Capacitors

Posted: Thu Jun 28, 2018 6:23 pm
by Dr Bunsen Honeydew
I am often asked to take amps back for service - WHY! - they are not cars. BUT the bullshitters have convinced you so they can rip you off !!!!!!!!!!!

READ THIS it is pretty much spot on, apart from different types and quality of caps do sound different.

http://www.analogrules.com/badcaps.html

Your chances of finding a bad cap of any type in an NVA amp, even 30 years old, is next to nil ! as we use well over specced capacitors for all uses and never subject them to high heat. Your only danger is capacitors drying out or rotting in a damp environment when not used for years, and I mean years.

I had an AP80 back here that had been stored for about a decade in damp and cold conditions and even most of the solder joints had rotted. The amp had to be completely rebuilt. Treat the amp with respect, store it with respect if needed, and it will go on working for your lifetime.

Re: Capacitors

Posted: Thu Jun 28, 2018 7:57 pm
by kellerist
Why? For example both the input selector and volume control of my AP50 are weared, and for some reason 2 inputs are working well, the others make a loud buzz. I bought it second hand from you, without any problem, and it worked until I was able to buy a new system. Survived movings and storing, I feel somehow that I don’t want to sell it in this condition for peanuts (like throwing away), but want to fix the problems instead and keep it for a second system in my room. I don’t know if capacitors are involved in any issue or not.

Re: Capacitors

Posted: Thu Jun 28, 2018 7:58 pm
by wiicrackpot
I've never in my hifi owning life fell for the capacitor upgrade stupidity,
it's worst since forums have spread this disease and you know who is the worst culprit?...AoS.

Re: Capacitors

Posted: Thu Jun 28, 2018 8:07 pm
by Dr Bunsen Honeydew
kellerist wrote: Thu Jun 28, 2018 7:57 pm Why? For example both the input selector and volume control of my AP50 are weared, and for some reason 2 inputs are working well, the others make a loud buzz. I bought it second hand from you, without any problem, and it worked until I was able to buy a new system. Survived movings and storing, I feel somehow that I don’t want to sell it in this condition for peanuts (like throwing away), but want to fix the problems instead and keep it for a second system in my room. I don’t know if capacitors are involved in any issue or not.
It needs REPAIR that is not SERVICE. IF you want it repaired then send it back.

Re: Capacitors

Posted: Thu Jun 28, 2018 8:20 pm
by kellerist
I will together with the P20 you are loaning me, as we agreed. It seems that I misunderstood the topic. To send back a completely well working amp, and risk the damage during shipping is not a clever move.

Re: Capacitors

Posted: Thu Jun 28, 2018 8:26 pm
by Dr Bunsen Honeydew
EXACTLY, and that is what service is, because people have been conned by slurping manufacturers and dealers, and promoted by knob head eeeediots like at AoS, to waste their time and money.

And if an amplifier actually benefits from a so called service it means it was badly designed or made in the first place.

Re: Capacitors

Posted: Thu Jun 28, 2018 8:30 pm
by karatestu
Dr Bunsen Honeydew wrote: Thu Jun 28, 2018 8:26 pm
And if an amplifier actually benefits from a so called service it means it was badly designed or made in the first place.
Mentioning no Naims :lol:

Re: Capacitors

Posted: Fri Jun 29, 2018 12:25 am
by Karnevil9
wiicrackpot wrote: Thu Jun 28, 2018 7:58 pm I've never in my hifi owning life fell for the capacitor upgrade stupidity,
Ive always changed Electrolytics in my Vintage amps, never fell for the boutique :bulls1 tho.

Re: Capacitors

Posted: Fri Jun 29, 2018 9:10 am
by _D_S_J_R_
Electrolytic caps CAN need replacement on some amps and I've seen the evidence myself - Quad were awful for this in the past long before Naim got started. Maybe narrow minded 'use the minimum rating necessary' thinking, I don't know.

NVA are kind on their supply caps, but not everyone was in the past (Quad, MF, Krell due to heat...) and some amps are almost designed to stress electrolytics on the main boards too (why do you think old Naims drift off so? I think latest production 'may' have sorted it but not sure)

Re: Capacitors

Posted: Fri Jun 29, 2018 9:30 am
by Vinyl-ant
The only time I have replaced caps in anything is if they have failed, and there is a fault that can be traced to them.
The only things I have found that they have failed on and have had to be replaced in is in early cd players and in dd turntables. Never in an amp. This has been due to heat, some dried out, and the fact that the caps were specced at very close to the operating voltage with only a few v wiggle room. Being hit with a much higher voltage than the spec is for a couple of times over the lifespan doesnt do them much good, and it's inevitable that this will happen at some point.
There is no such thing as a service for a piece of electronics, it either works or it doesn't. If it doesn't work, then fix it. If it does, changing caps can alter the sound. But it isn't a service, its an 'alteration.
Caps do have a sound, that is what people hear when re caps are done. its not like having new shocks put on on a car to replace nasty old leaky ones and suddenly its no longer a wallowy barge any more and it back to handling nicely again.....