solid audio f-15d distorted when loud

hello! i need your inputs, why my solid audio amp has a 65v single rail voltage? it has only 3 big bulk capacitors in parallel. im thinking it will not be loud as other that has dual rail voltages. other 1500 watts amps has dual +-80v to make 1500 watts. thank u
 
hi perry, ok thanks. but this amp becomes distorted easily when at mid gain. pls see my hand writing sine output. i replaced hp4080 driver but still the same.
 

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1) your amp probably has a bridged power amp, so your single 65V is equivalent to 2 x 65V split supply.

2) in any case, "all others" use 80V rail(s) for "1500W" , you only have 65V available, that means you have around 60% of "their" power possible

3)n in any case your amp has a 30A fuse.

So with ideal 14.4V supply (with car engine revving up) your maximum **DC input power** is 30*14.4=432W input and with average 12.6V from your battery some 30X12.6=378 W input

Given that´s "fuse blowing" power plus amp is not 100% efficient, ven if Class D, I suspect your amp has no more than 250/300W RMS.

And that for 1 ohm load (their spec, not mine).

But that´s easy to check: connect a scope across speaker out, inject a 250 Hz tone to input https://www.mediacollege.com/audio/tone/files/250Hz_44100Hz_16bit_30sec.mp3 , start rising volume until it clips, slowly lower it until it cleans up and measure voltage, calculate power.

EDIT: your waveform seems to show that the positive half collapses under maximum load.
When/if that happens, disconnect load, or switch to a higher value one (i.e. 2 ohm>4 ohm) , what happens?

I see it more as an "output MosFets can´t handle the current" problem than anything else.

Maybe one blew open (or a related tracks) leaving the one(s) in parallel with a harder job to do, which is only noticed at highish power.
 
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