DIY Good Class D amplifier

Yes,limit is FET voltage.I use IRF640N,BUZ60 and IRFZ44N and all works OK and cold (only BUZ can get little warm).Gate drive FET can be any same or voltage as outputs,min. 4A,with smaller Qg.
Here's schematic without transformer.
470p...2n2 to change frequency.
 

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My friend make my amp from post #268 and he say it's very loud and has high power.He use 48VDC as power and now test on 2 ohm load:
 

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Completed amp from my friend,he says it's great for he :)
 

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Single,later used 110V (two 55 in series) but it has cooling problem on 1 ohm because current is high (peaks is over 30A,which is more than my fet's can handle,I use four IRF640)
If use fets in parallel,change BC639 and 640 with BD139/140 and make each fet has own gate resistor and diode.
 
And this is amp for PA,not for Hi-fi,friend says a mid's has lower volume than high's and bass,instead of TDA7294 but this can be corrected with changing value of input cap parallel with 47k and parallel with gain resistor (I suggest him simple circuit to get more gain,only cut pins 2 and 3 and make classic amplifier like opamp.- input is pin 2 and out is pin 3.Only add 10u to 100u cap from ground in series with 1k to pin 2 and use parallel RC (R is for gain,470R to 10k or more if needed,C is 47p to 100n,for filtering) placed to pin 2 and 3.
 
And this is amp for PA,not for Hi-fi,friend says a mid's has lower volume than high's and bass,instead of TDA7294 but this can be corrected with changing value of input cap parallel with 47k and parallel with gain resistor (I suggest him simple circuit to get more gain,only cut pins 2 and 3 and make classic amplifier like opamp.- input is pin 2 and out is pin 3.Only add 10u to 100u cap from ground in series with 1k to pin 2 and use parallel RC (R is for gain,470R to 10k or more if needed,C is 47p to 100n,for filtering) placed to pin 2 and 3.

please draw a simple schematic to explain the modification above.

and how is the clarity of this amp compared to irs 900d ,also is it silent or does it have switching noise issues?
 
Completed amp from friend,gain and schematic that i currently use (better than 494 in all cases):
 

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I test IRFP260 here,but you should use BD139/140 instead of BC.
Supply is limited by fet's,if use higher voltages place driving fet (T6) to heatsink too.This fet can be another cheaper FET,like IRF6xx or IRF740.I use there worst case FET,IRF840 (high Qg and capacity).With better FET overal amp only can get better.You can vary resistors in gates (R6 and R12) from 10 to 100R,but use one that heating of fet's is minimal,but not too high,because of slow gate drive.