Quick Dumb question

[K-amps]

I am drooling over the 60 amp trafo !!

 

[K-amps]

Built the PSU... one of the more stable ones I have built.

Non-signal rail steady at 59.5vdc. Full power into 2 ohms** at clipping and the rails sag only to 56.5vdc... I have never seen this in an amp I owned before.

3x Panasonic 27,000uF paralleled. Bypassed with 1000uF, 120uF and 0.5uF per rail.

CL-40 on the primary.... no smoke yet


** Four 8 ohm woofers in parallel... yes they were bottoming at times. I reckon I am getting 600w into 2 ohms RMS. Have not done more measurements. By the way, I have not yet installed any inductors.

 

[K-amps]

Actual results: 8 ohm clipping 190.34 watts (600Hz sinewave). At 4 ohms 330.31 watts RMS. PSU droop at 8 ohms 57.2 vdc (from 59.5vdc).

PSU droop at 4 ohms 56.7vdc.

Now while (because I think I biased it 5 watts class-A plus the higher device temps i.e. 40C) the sound is softer than before, there is more midbass. I am not sure if this is good thing or not but the 100-200Hz is pronounced. Is this because of the PSU going from 12000uF per rail ro over 82000uF per rail?

 

[jacco vermeulen]

Non-signal rail steady at 59.5vdc, into 2 ohms sag only to 56.5vdc Getting 600w into 2 ohms RMS.

Very impressive, Arif.
A 2 Ohms power number between 2.5 and 3 times the 8 Ohm continuous power is already good.
This is with the 2KVA transformer ?

 

[K-amps]

Yes with the mystery 2kva trafo that looks like 1kva .

The caps are Panasonics. 105deg: 63wv, 79v surge, 27000uF CE THA series.

 

[K-amps]

Close-up.

The caps were not the screw mount types so I had to jury-rig some bare copper busses, Seem to work fine.

At full power the rail sag (measured from cap junction to the collector of the OP device is 0.39mV ).