Hi Franz,
I read your post with interest and hope that the following comments might be of some use as you contemplate what to do moving forward. As you know, I do indeed use a TacT 2.2 XP based DSP system. It is somewhat unconventional in both hardware and configuration. The hardware was modified by Anthony Padilla who incorporated several levels of modifications including modified power supply, upgraded A to D and D to A boards, and finally internal wiring (Nordost-like cabling). Although I am extremely happy with it, there are many posts on many forums that suggest that the future of TacT in uncertain. In addition, although I have always found Anthony to be a very reliable provider, others have not. Although he has, in my opinion, changed the Tact 2.2 XP from a utilitarian component to a true SOA one, it is unclear if he will be joined at the hip to Boz's future activities at Emotiva or elsewhere. Thus, I am extremely sympathetic to not wanting to go down the TacT path at this point. Please consider that I do not use the preamp (gain) functions of the 2.2XP. All of my gain function is provided by my VTL 7.5 MK III preamp and the preamp portion of the 2.2XP is simply bypassed. I use the TacT both for DSP EQ and most importantly, as a crossover. The low pass goes to dual Gotham subs and the hi pass goes to VTL Siegfrieds which feed my Pipedream towers.
So with TacT out of the running, what other DSP solution are out there? We'll you've touched on some of them, which include DEQX and the Lyngdorf system. I recently heard the STeinway Lyngdorf models C and M at Overture Electronics in Wilmington Delaware and was simply knocked out. The M system at about 40-45 K is probably more of a system than anybody needs- its that good. But keep in mind that Lyngdorf incorporates his digital amps into his systems, and many people are not attracted to that. The DSP unit he uses is basically a TacT, which of course makes sense since he is both the father and now, the direct descendent of TacT. The key for me in understanding the excellent sound he manages to maintain is quite simply his target curve, which he publishes in the Steinway-Lyngdorf literature. I won't go into details here, but it is somewhat different than anything TacT suggests. Indeed, when I adjusted my own system to the Lyngdorf target curve, I found it more satisfying than the myriad of curves I had tried previously. They were subtle differences perhaps, but significant ones, at least for me.
What I'd also like to suggest, for your consideration, is to explore some of the outstanding DSP products from the pro-audio world. Specifically, the units that you might want to consider are made by Behringer in Germany.
http://www.behringer.com/EN/Products/DCX2496.aspx
http://www.behringer.com/EN/Products/DEQ2496.aspx
One is a DSP crossover and the second is a DSP equalizer. What's really nice is that they provide superb performance and are about $400 each. That's right, I did not leave off a zero. Another way of saying this, is that they are not considered "audiophile" products, but rather instruments that mortal musicians use and are therefore affordable. But don't let the price fool you. They have garnered stellar reviews universally from serious critics. Thus, here we have both of the essential features of the TacT (EQ and crossover), available separately, for very little money. What's not to like!! Keep in mind that I mentioned that one of Anthony's signature modifications on the TacT 2.2XP was to the power supply. Many have said, and I agree, that it is the best value per dollar of all his modifications. The point that I wish to make is that my sense is that if anybody wanted to modify the Behringer units accordingly, I am guessing that replacement of the common half wave rectifier power supplies commonly used in such gear, with a fully regulated power supply, is something that could be done by any number of competent technicians at a very reasonable price. That said, I am not sure the Behringer units need such modifications, my only point being that it's probably doable if one wanted to go the extra mile.
I'll conclude by saying that the Behringer units seem to offer outstanding performance at a very modest price, which I hope will encourage many members of this forum to try DSP in their systems. If you've heard a good DSP system, you'll appreciate the enthusiasm that many of us have for at least exploring this option. There simply is no substitute for a system with a relatively flat frequency response and good effective DSP is certainly one way to achieve this. At these prices, you'll lose little if in the end, you decide it's not for you.
Marty
