I've gotten some information about the TacT 2150 and 2150X amps that is worth mentioning, in case anyone is looking to buy a new amp or upgrade an older one.
This is not from my experience, but from someone who is intimately familiar with the TacT products and has used/dissected them all as well as the newer Boz amp.
The "X" version has a new DSP board which incorporates some of the featuers of the Boz line, mainly DSP crossovers and parametric EQ that can be implemented via the remote control and front panel display, without computer software. There is also a provision for room correction in the amp. But the outboard measurement box is still not available, and the DSP board cannot do room correction and crossover/EQ functions simultaneously -- one only can be active at a given time.
There is no sonic improvement with the "X" version. No improvements have been made to the power supply, capacitor banks, or Mosfets. The upgrade is limited to the DSP board and software. The "X" amps may have a new issue which could cause sonic problems in some systems -- the "free" 12dB gain of the 2150 amps is gone, and any gain setting above 0dB apparently results in an over-modulated, distorted sound. In my system, I have the S2150 set at 12dB gain and definitely need it to get adequate volume on some classical recordings. Since the amps do not have a true volume control (they attenuate by modulating the rail voltage instead of manipulating the signal), the lower levels needed for typical compressed recordings do not result in any resolution loss.
It sounds like a new or used, plain 2150 with the free
TACS software may be the way to go, unless you really don't want to use a computer for crossover and EQ design. I certainly would not pay the $1200 upgrade fee for older amps, the free TACS download gives more functionality and preserves the nice 12dB gain.
