The Natural Philosopher wrote:
Phil Allison wrote:
"The Natural Philosopher"
Unless its split rail with two 80V caps, or an H bridge..in which
case yes, its abut 400W.

** That is a bit optimistic.

1. If the filter electros are each rated at 80VDC working and one
sensibly allows for higher than nominal AC supply - then the
*unloaded* DC rails are likely to be +/- 74 volts.

2. If the AC tranny is of conventional design ( toroidal or E-core)
then the regulation factor is such that the average DC rail will drop
under load by about 12%.

3. If the capacitance is a typical value like 6800uF for one channel
- then the p-p ripple voltage under steady load is about 4 volts -
more if the audio test frequency is under 100 Hz.

4. An output stage is never able to swing to the full extent of the
available DC rail voltage - particularly so if the output devices are
lateral mosfets. Assuming a typical complementary Darlington output
stage with emitters supplying the load - the output can swing within
about 5 volts of the available supply with an 8 ohm load.

Adding this up we have:

74 - 9 - 2 - 5 = 58 volts peak.

No. 58 volts peak TO peak.


So the "rms" power on sine wave into 8 ohms will be 210 watts.

No, slightly over 50W.


Ok I see you are talking about split rails. I read the above too
quickly. I don't think the OP mentioned that he had split rails.

So your analysis is correct for what equates to a +-60V supply.

However I have yet to see that sort of power and arrangement outside
some pro audio kit.The semiconductor cost is pretty high above 100V.






..... Phil