Re: Size of power supply capacitors



> So: is there anything to be gained (probably in lenearity at high
> volumes) by increasing the capacitance a factor of 2 or 4? I tread
> gingerly into 'audiophool' territory here, I fear. I even wonder if one
> of the reasons this amplifier is so nice to listen to at high volumes
> is due (in addition to the mosfet output design) the drop in supply
> voltage, leading to a gentle compression rather than a clipped signal.

Absolutely, if you're running into the ceiling occasionally with dynamics.
Haflers have a significant sag with the power supplies. Increasing the
storage capacity will extend the peak or dynamic momentary power output
ceiling by double, triple or more. When driven hard, the Hafler with much
bigger caps will sound like a bigger amp. Damping factor improves, too,
which you'll notice at more modest volume levels. Deep thumping bass drum
sounds have more power with larger caps, because the rail voltage stays high
for a longer period. If you have enough capacitance, the amp can ride out
the duration of a bass drum hit with little sag. The default caps sag 20V in
less than 100mS.
I replaced the 20,000uF caps in the DH-500s here with 45,000uF caps custom
made for me by Phillips under order through Hamilton-Avnet. The caps cost
me $127 each back in 1990 or so when I ordered them, but the upgrade was
well worth it. But I drive large arrays of 18" woofers and have racks filled
with DH-500s, so my application definately brings out the effects. Your
mileage may vary. If you use it for low volume listening, you probably
aren't going to notice the difference unless you have unusually-dynamic and
percussive material.
Good, low ESR, high temperature caps are expensive, but the benefit can be
significant.
Take it from a "Bass Pig" --where amps to the woofers count big time.

--
Best Regards,

Mark A. Weiss, P.E.
www.mwcomms.com
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Relevant Pages

  • Re: Size of power supply capacitors
    ... > Haflers have a significant sag with the power supplies. ... Mark is a know nothing FOOL!! ... > bigger caps will sound like a bigger amp. ...
    (rec.audio.pro)
  • Re: More power supply
    ... I ordered a three phase rectifier for my 240 Vac in 100 amp DC power ... Next issue is capacitance. ... That's a lot of caps, I'm concerned about start surge current. ... The original power supply didn't use any significant amount of filter ...
    (rec.crafts.metalworking)
  • Re: Computer totally freezing after a few min
    ... Well, in that case I would try replacing the bulging caps, see what ... processor or the motherboard could have further damage. ... It might be there was a power surge that could have partially damaged ... That stupid 'ol train is still ...
    (alt.2600)
  • Another tale from the capacitor plant
    ... That wasn't the only product the plant made, ... Primary power was applied through a Variac with a LONG cord! ... an arc popping the breaker, ... but it contained filter caps. ...
    (alt.sysadmin.recovery)
  • Re: Computer totally freezing after a few min
    ... Well, in that case I would try replacing the bulging caps, see what ... processor or the motherboard could have further damage. ... It might be there was a power surge that could have partially damaged ... That stupid 'ol train is still ...
    (alt.2600)