I have been quite curious about digital amplifiers ever since hearing an early TacT amplifer at a show (very interesting). So when it became available, even though it misses a digital input, which I think is important, I bought a t-amp and hooked it up. It sounded quite nice so I decided to re-box it with a better power supply, 'cause I didn't like the no mains socket, no phono sockets, no 4mm sockets, plastic box.

Look how small it is!

Showing my direct connections to the board.

I have added a 30VA 12V transformer with Schottky diode bridge, coupled to a monster cap, then through a 5?A LM337 TO3 regulator, and then in to some more decoupling caps. I added an OSCON (low ESR) on the board as directly across the power pins of the chip as was practical, to help shunt away nasties. I removed the volume control and power switch, but as of the moment am still using the SMT input decoupling filters.

So how does it sound?
In my office at the moment I have an old SONY (3140f) amp and my hybrid transformer coupled class A mosfet amp. The most noticeable thing is actually the absence of high frequency nasties. It sounds fairly clean and trouble free, if lacking the last degree of wallop, compared to the SONY (which has now died). Compared to the 1MHz amp it is quite impressive with a nice black background, and clear separation between instruments. It does lack that last bit of smoothness and silkyness that the 1MHz amp has however and the bass is a bit rolled off, but quite tight. If I was using a normal transistor class B sub £1000 amp I would say you should notice an improvement, and a reduction in power, if the rest of the system was up to it. I prefer the hybrid for the office, but the T-amp is fine, it just gets on with it and doesn't grate.

It is a pity that the datasheet is not more forthcoming about the input opamp. It would be very interesting to try bypassing it and feeding straight in...