Motherboard-Grade Capacitor + Audio?

[TheLaw]

Hi,

So, I'm in the middle of about 16 different projects right now. PSU recap, Video card recap, Amplifier build, Headphone amp build. Headphone amp is almost done...but...

I was curious. It seems a lot of people use Panasonic FC/FM for audio. They're great caps for sure. I love them.

For signal path and for instances where low ESR is important, how would a motherboard grade cap stand? Say a Nichicon HN/HM? For some reason, I would think they aren't as tolerant/tough as an FM, but perhaps not.

That's all.

I'd love to hear your opinions.

Thanks.

[kaboom]

Re: Motherboard-Grade Capacitor + Audio?

I've used Panasonic FC and Nichicon HE for speaker coupling and NFB return in things like TDA2002 amps. You're good. The demands of something like a headphone amp are nothing like that of an SMPS- the caps will live an easy life. I've seen people get into the audiophoolery over at audiokarma about coupling caps in the old amplifiers. It's unfounded. They scour fleepay for 30 year old caps. These people need to realize that new caps are so much better as far as leakage is concerned. A case of DC offset at the speaker terminals comes to mind. After much fuss over what was 'wrong' with the final, the 'vintage' cap was replaced and the offset went away.

Same thing with my Sansui 881, except I replaced them all...

If ya gots 'em, use 'em. Don't worry about that 'it affects the sound' nonsense.

-Paul

[PCBONEZ]

Re: Motherboard-Grade Capacitor + Audio?

I'm not an audiophool but I've also heard FC and FM do well.
.
Audio grade are fine for mobo use [given the ESR/Ripple are okay] but not necessarily the other way around.
-
The difference is how the foil is etched before the oxide layer is formed on the foil.
[I dunno in depth details on that one, just know that's where the difference comes from.]
Somehow the 'graininess' of the oxide layer affects some audio frequencies.
Motherboards just 'don't care' about that. Doesn't hurt, doesn't help.
.

[TheLaw]

Re: Motherboard-Grade Capacitor + Audio?

Thanks guys. Just curious. I'm using FM on the headphone amp, and I think I'll be using FC/FM on the big 150W+ amp.

[linuxguru]

Re: Motherboard-Grade Capacitor + Audio?

Some low-ESR computer grade caps are ok for audio - Panasonic FC/FM/FJ, Rubycon ZL, Chemicon KY, Nichicon HD/HE. But in most cases, they are less linear than specialty audio-grade caps and may sound too harsh in many audio applications. The dielectric soakage will be much higher than audio-grade caps.

The other issue is that most low-ESR or GP caps have magnetic leads (either steel-cored or Nickel/Kovar-plated), which have a number of frequency-dependent effects (eddy-current losses, higher lead inductance, etc.) as well as EMI pickup/radiation issues, compared to audio-grade caps with pure copper leads and Sn/Pb plating.

The combination of high capacitance, low ESR and high lead inductance is a recipe for creating high-Q LC tank circuits and unwanted resonances at frequencies as low as a few kHz to 10s of kHz.

If you keep the leads short and away from high-current interference sources, you can get away with using low-ESR caps for audio. Otherwise, it invariably leads to a tinny, harsh and sibilant grating sound which won't pass audible blind testing.

[TheLaw]

Re: Motherboard-Grade Capacitor + Audio?

Good points but audio-caps aren't very "heavy duty". I think I'd prefer something that might last longer vs something that will degrade over the course of it's life, but might sound a tad bit better. And almost all are 85C.

I tell this to people all the time: My Logitech 2.1 $30 Best-buy special used Cheng, CapXon, and a few Samxon GPs and when I recapped it in Nichicon FG/KW + Panny FM, I swear I heard no difference. Maybe I don't have very good ears, but I just don't get it.

It's just hard to get around.

Thanks.

[PCBONEZ]

Re: Motherboard-Grade Capacitor + Audio?

Good points but audio-caps aren't very "heavy duty". I think I'd prefer something that might last longer vs something that will degrade over the course of it's life, but might sound a tad bit better. And almost all are 85C.

I tell this to people all the time: My Logitech 2.1 $30 Best-buy special used Cheng, CapXon, and a few Samxon GPs and when I recapped it in Nichicon FG/KW + Panny FM, I swear I heard no difference. Maybe I don't have very good ears, but I just don't get it.

It's just hard to get around.

Thanks.

Cheesy IC amp in those can't do any better even with good caps.
.

[TheLaw]

Re: Motherboard-Grade Capacitor + Audio?

True. They weren't using anything special for sure. I'm building an LM3886 x2 + LM4780 bridged amp right now and I'm contemplating this audio-grade thing...I think I'll just stick with a combo of FC/FM.

Oh by magic, the Mouser box arrived today for the PSU recap. Did about 4 small caps so far. All fit, no casualties yet. =D