Hi SIS,
Thank you for your inquiry! You raise pivotal issues about rail voltage and this bears some explanation.
Now, for more power on an amplifier you need more volts on the rails, so you can swing more voltage across the load. The peak to peak voltage across a nominall 8R load gives power, according to the voltage squared and then divided by 64. So 80Vpp gives us precisely 100W into 8R.
To swing more voltage across a load, you naturally create a higher current, since current, by Ohm's Law, is volts/resistance. More current and more volts generally means a bigger output device, or, in the case of most solid state amplifiers, more output devices of the same size.
So it is with the AKSAs. The 55W has a single output pair, one npn and the other pnp. The 100W has two output pairs, two matched npns, and two matched pnps, to accommodate the higher voltage and the higher current.
And here's the rub; 300VA transformers with 33-0-33Vac secondaries will generate around 50V rails on a SS amplifier, and this is too much for the single output pair on a 55W AKSA. This high voltage will create large currents through the load, and all this current - up to about 6A - will pass through just one device at a time on the 55W, rather than being nicely shared on the 100W. At this high voltage and current, you will invoke a failure mode called secondary breakdown, and the output devices will lay down their lives to protect the fuses.......
Don't do it!
If you have the large transformers, go for the 100W AKSA because it is designed for precisely these trafos!
Cheers,
Hugh
