Long time lurker, posting for the first time here.... I can chime in on the Soloist SL...I bought about two months ago
My first solid state headphone amp...I have been using a Decware CSP2 for 3+ years, with Sennheiser HD-650 and AKG 701's
The Senn. 650's with the OTL Decware CSP2 is a great match. However, the AKG 701 not so much... so, the AKG 701's sat on the sidelines over the last few years
Recently, acquired the Soloist SL and the Beyerdynamic T-90's....
All my headphones sound great with the Soloist SL, especially the AKG 701, they have been brought back to life...
The 701's just needed the current drive that the Soloist SL has on tap.
The Beyer t-90 and the Soloist are also a special match....all the detail, soundstage depth, and perfect high-end you could ask for in a headphone amp/headphone pairing.
Comparison between Decware CSP2 and Soloist SL...interesting indeed. It made me realize that the Decware is really great, no lack of detail or too much tube warmth...just whats on the recording, with just enough of that tube "sweetness" "distortion" (for lack of a good descriptive word) to make me glad that I have a choice with tube or SS
The Soloist is still more detailed and the separation of instruments is better....no harshness at all, really delicate detail and presence with all the headphones used, but especially the AKG 701 and the Beyer t-90
great to see a thread about this bargain of a headphone amp from Burson