I´m also building an Aleph5 (just finished drilling the pcb´s).
I will use one 600VA 25volt transformer per channel. This will give me the possibility to increase the bias current (if my heatsink arrangement will allow ).
The transformers are fully impregnated so I hope the mechanical noise won´t be too high......
The ratings for transformers are almost always listed as an AC rms voltage. Therefore, you must divide by 0.707 or multiply by 1.414 to determine the peak voltage that the transformer delivers to the rectifier for your power supply. Calculate the voltage drop the rectifier has on your AC voltage and that is to what your capacitors will be charged. So,