You'll need to increase the dropping resistors for the driver stack and the input transistor. I used a voltage regulator zener for my input transitor at 60 v (two 30 v zeners).
If you use MJE15030/31 for drivers with heat sinks, you can easily pump enough current in the base of the dual output transistors. You might need to decrase the 220 ohm resistors in the driver stack, calculate your soa load. I've used a TO220 with 20 mhz Ft for the VAS, so that allows you to use a big heat sink there, too. It was a genuine GE D44-R2 no longer availble except in no specs clones, so I would use a MJE15030 there too.
There was a slightly more sophisticated 4 output transistor single rail amp posted the m2rac that had a long tail pair input, but I've lost the link to the thread.
Actually that is too much DC voltage for most 8 ohm speakers. 62 vac you could get out is 480 W which is too much for drivers costing less than $100. that is 7.75 amps at 8 ohms, so if you wanted 4 ohm capability you'd need more like triple output transistors. You would need a crossover for the tweeter and serious overvoltage protection for it like a PTCR fuse. Here in the states there are plenty of PV-1.3k or PV2000 sold on e-bay for parts that would get you a +-85 v transformer. Plus a big heat sink and a 5" fan. I bought my PV-1.3k for $57. But I don't know what you can buy in your country, metal scrappers are pretty aggressive some places. For home use with 20 W surplus projection TV speakers, I picked up a PV-4c for $20 +28 freight. Just needed output transistors, rail caps, input caps. I increased the heat sink fins on that it had output transistors replaced 4 previous times.
If you use MJE15030/31 for drivers with heat sinks, you can easily pump enough current in the base of the dual output transistors. You might need to decrase the 220 ohm resistors in the driver stack, calculate your soa load. I've used a TO220 with 20 mhz Ft for the VAS, so that allows you to use a big heat sink there, too. It was a genuine GE D44-R2 no longer availble except in no specs clones, so I would use a MJE15030 there too.
There was a slightly more sophisticated 4 output transistor single rail amp posted the m2rac that had a long tail pair input, but I've lost the link to the thread.
Actually that is too much DC voltage for most 8 ohm speakers. 62 vac you could get out is 480 W which is too much for drivers costing less than $100. that is 7.75 amps at 8 ohms, so if you wanted 4 ohm capability you'd need more like triple output transistors. You would need a crossover for the tweeter and serious overvoltage protection for it like a PTCR fuse. Here in the states there are plenty of PV-1.3k or PV2000 sold on e-bay for parts that would get you a +-85 v transformer. Plus a big heat sink and a 5" fan. I bought my PV-1.3k for $57. But I don't know what you can buy in your country, metal scrappers are pretty aggressive some places. For home use with 20 W surplus projection TV speakers, I picked up a PV-4c for $20 +28 freight. Just needed output transistors, rail caps, input caps. I increased the heat sink fins on that it had output transistors replaced 4 previous times.
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