Thank you. I am still confused about how 120,000uF only equates to 30,000uF. My JVC RX-DP9 has 33,000uF 63v. Does this mean that the JVC has less "real" capacitance as well?
Ok here is some basic info on how capacitors add:
In Series: 1/Ceq = 1/C1 + 1/C2 + .... 1/Cn
In Parallel: Ceq = C1 + C2 + C3 +....Cn
It is ALWAYS preferred to wire caps in parallel so the effective capacitance is additive and the ESR (effective series resistance) is lowered.
Where Resr(series) = Rs1 + Rs2 +.... Rsn
and Resr (parallel) = [1/Rp1 + 1/Rp2 +....1/Rpn]^-1
When I first saw the pic of the XPA-2, I noticed 12 (NOT 10) 10,000uF 50V caps. If they were wired in parallel, the Equivalent capacitance would be 60,000uF per rail or 120,000uF total (2 rails). The probem is 50V caps are only good for rail voltages of about 45V max. This would be fine if the amp was rated around 130wpc continuous but its not. Thus the only way to get the V rating high enough is to wire them in series which would yield 100V rated caps. Thus what this would imply was that each capacitor pair was wired in series and than the pairs were wired in parallel.
Its basically a series/parallel combination:
1/Cs = 1/C1 + 1/C2
Ceq = Cs1 + Cs2 + Cs3
Ctotal = Ceq1 + Ceq2
where each pair of 10,000uF caps wired in series equals 5,000uF then wired 3 pairs in parallel would yield a total of 15,000uF per rail or 30,000uF total power supply capacitance.
According to Emotiva, they are changing these to a conventional parallel topology, upping the V rating and reducing each C value. This is a GOOD change.
