At a load of 4 ohms, the power of this Amp is 1 kW. 2x110V is the maximum power supply voltage for this amplifier.
I draw your attention to the board instead of resistor R13 installed multiturn resistor for adjusting the quiescent current of the output stage transistors, as well as in the difcascade instead of the constant resistor 1k installed multiturn resistor 1k in series with 470R to minus power supply, which allows you to adjust 0V at the output of the power amplifier. Amplifier works in class AB. The optimum quiescent current of the output stage transistors is approximately 26 mA. The radiator with output transistors has forced cooling, that is, we put the fans. The developer recommends the installation of two 0.14A / 220V 120×120 mm fans connected in parallel.
Instead of MJL4281A / MJL4302A transistors, you can put MJL21195 / MJL21196 or MJL21193 / 94. The MPSA92 difcascade transistors are in contact with the cases, they can be pulled together with a shrink tube for thermal contact.
About the resistor R11 10k / 2W – it will be hot, you can increase its power up to 3 or even up to 5 watts.
Transformrr: recommends the use of 1500VA transformator, 2 x 75V AC secondary (breaks) with a current of at least 10 Amps, a 50 Amp rectifier bridge of type KBPC5010, and 4x 10000uF / 120V elcos for one channel. For the stereo version of the power supply should be in the region of 2 kW.
pcb is FR4 1.6mm 2oz Green