Thanks for the info, Stereo. The funny thing is I'm awaiting delivery of Audio Mirror's SET 45 amps which are supposed to arrive tomorrow. I couldn't replace the Tact with another preamp, as I'm using the Tact for digital room correction and crossovers. All I can do is add an analog preamp like the T-61 after Tact and before the amps like this: CD Transport -> Tact -> Outboard DAC -> Active Preamp -> Amps.
I'm also looking more closely at the possibility of upgrading my outboard DAC for a higher voltage level which would eliminate the need for an active preamp. I've been noticing that there are several high end DAC manufactures that think the Burr Brown 1704 (which I have in my DAC) was the most musical DAC made (it first came out in 1998) and are still using it in their products. I do really like the sound of my DAC, but it does not currently provide enough output voltage, which was the original reason for this thread.