I just serviced one the earlier Portaphile Amplifiers, a V2^2 (read V2 Squared) Maxxed. This amplifier is a predecessor to the 627 line of amplifiers where there are three channels (L, R & G) plus two buffers per channel (for a total of 6 BUF634u). It was powered by a single 9V battery which provided a voltage swing of +-4.5 volts on a fresh battery. Because of the lower voltage available, I built the amplifier around Analog Devices AD8610’s where there were three opamps, one each for L, R and G. It also used the legendary Black Gate NX capacitors in the power supply which eventually resulted in the V2s demise. When I started building the V2, the best capacitors I could find were the Black Gates but they were already going out of production. As soon as the limited stock in the marketplace was gone, I decided to retire the V2^2 Maxxed and started working on it’s replacement, the Portaphile 627.
If your familiar with the V2^2 Maxxed, own one currently or had one in the past, please post your thoughts here. I’d like to hear from you!