Ctchen,
I would think that, owning a DK, with a tube preamp section--you may miss the 'warmth' that tubes offer in the overall sound.
To realize the value of tubes in the preamp section, one needs only to 'switch' the tubes for another brand or design to realize how much of the sound is dependent on the preamp section. The DK amp, depending on the tubes used, sounds completely different when the tubes are changed. If you can audition the Tact, you may, in fact, like it better. This is the point at which 'personal taste' enters the picture.
We have heard the Tact under non audition conditions, and recognize it as being a fine product--though very different than the DK.
I would again, recommend that, since we have tubes vs. a digital amp, you audition the TACT carefully-as the sound probably doesn't get much different than these two.
I prefer the warmth of having Telefunken Tubes in my unit--that doesn't mean that everyone will.
Thanks for buying a DK. Please, let us know what happens, and how this turns out.
Best,
Larry R Staples
DK Design