Ok, so first of all hello to everybody here  8| So I have these chip and transistores spare in my junkbox and I thought I could upgrade my  TDA2030 10-15w practice amp  that I built some years ago. Now, I have this schematic for TDA2030+BD243A/BD244A current boost or something hybrid amp design that would suppose to deliver 40W into 4Ohm load at +-22V. I don't have a scanner so I can't post the schematic right now, but maybe someone could tell me if I could just use TDA2050+BD249C/BD250C instead or would I have to change the values of the other parts as well? For the power supply I have two transformers to consider: 2X18(center taped 36v?) and 2X24 (not quite sure about Amps though, the 2X24 one is over 2A i think) so would those be suitable, could all that work, and how much output would I get out of it? Is it worth bothering or should I just swap the TDA2030 with TDA2050. For the TDA2030 amp I used 2X9V transformer and that was too much for the chip so I put two 9V zener diodes to have exactly 18v for the power amp section. For TDA2050 I'd just remove those diodes so I guess it would work fine for some 25w amp into 8Ohm load. So what do you guys think?