Jethro - do the BP25 inputs have the same problem with large RCA plugs as the .5 ?
And Dan, any comments on what you found better in the .5 than the ASL 2004? One would think that the ASL with newer technology and the "toob" advantage would have something the older .5 does not.
BeeBop,
Keep in mind that the AQ2004 is the 1st piece of tube gear I have owned. I have rolled the tubes and the current valves are a pair cryo-treated CITFE ECC82s (French military 12AU7s) and a GE JAN 5751 (low gain 12AX7, US military variant). The rest of my system consists of a Sherbourn 5/1500A SS power amp, a Carver SD/A-360 CDC, MMF-5 TT, RP-91 DVD-A (for hi-rez stereo) and Vandersteen 2C speakers. I am using a Yamaha RX-V596 receiver as an HT pre-pro. I am much more of a music than movie fan and the Bryston is another improvement to the 2 channel performance of my system.
The 1st thing I noticed about the Bryston was the soundstage, it is more 3 dimensional and more stable than the ASL pre. The AQ2004 doesn't convey the sense of depth that I get with the 0.5B. In visual terms, the AQ2004 is like looking at a very nice painting, while the 0.5B is like looking at the same painting, rendered as a mural. The image just seems better defined with the Bryston than it does with the ASL.
The ASL definitely warmed up the mid-range and that really came through with some singers. But the 0.5B also has a nice mid-range and it handles the highs and especially the lows noticably better (IMO) than the AQ2004. The result is a more balanced sound across the entire frequency range, rather than the comparatively warm and emphasized mid-range of the ASL pre. I actually preferred the AQ2004 when listening to Sade, Jacintha and even Sam McClain. But I am more of a rock fan than jazz and the 0.5B sounds better to me when listening to Elton John, Supertramp, The Moody Blues, Pink Floyd and Stevie Ray Vaughn, to name a few.
The 0.5B is quiet! With no input and even with my ear next to the speaker I cannot hear a difference in noise levels with the 0.5B off or on, until I have the volume cranked almost 3/4 the way up. OTOH, I can hear the AQ2004 as soon as it is turned on, even with the volume at minimum. And with the volume control set for my normal listening level I can hear the AQ2004 from my listening position, ~12' away from the speakers. It isn't loud or obtrusive, but I definitely can hear the ASL pre and I don't hear the Bryston.
I think the Bryston more accurately reproduces the sound from the source material than the ASL. For some people that's not a big deal, for others it is. I tend towards a preference for accuracy, but not at the expense of brightness or fatigue. For me, the Bryston does a better job at that than the ASL.
Convenience was another factor, the ASL only has 3 line level inputs and no tape loop. The Bryston has 3 LL inputs, a tape loop and what I have been told is an excellent phono stage. With my TT, CDC, DVD-A and HT pre-pro, I need 4 inputs, so the ASL just won't cut it. BTW, I never intended for the ASL preamp to be permanent. I was looking for an inexpensive way to improve the 2 channel capabilities of my system and I wanted to test the tube waters. The ASL pre fit the bill on both counts.
Some other points to keep in mind, the ASL AQ2004DT is an entry level mid-fi piece that sells new, with stock JJ tubes, for less than $350. The Bryston 0.5B is an entry level high-end piece that sold new for around $1500. Yes, the AQ2004 is 10-15 years newer, but it is still a mid-fi unit and it really isn't a fair comparison. Another point is that I do like the ASL preamp, especially for the price. Its has a very nice, warm sound quality that works very well with vocals, especially female. But the Bryston also does an excellent job with vocals and its overall performance matches my personal listening preferences better than the ASL.