I recently got an Audio Mirror T-61 preamp. My impression from having listened to it for a few days is overwhelmingly positive. The one-word description (both sonically and physically): Beautiful.
Physically, the T-61 is a work of art. Simple, modern, and elegant. The faceplace is a beautiful metallic, and both the selector and volume knobs are solid and have good tactile response. The remote does the job, but is nothing to write home about. It also doesn't work well off-angle. The preamp also defaults to the CD input when turned on; I would prefer if it remembered the last setting.
The Audio Mirror preamp uses a pair of 6N1P tubes for amplification (a third tube is used for the power supply rectifier). The 6N1P is a higher filament current version of the ECC88/6DJ8. It's not clear to me yet if a 6DJ8 can be substituted. If not, then tubes are going to be limited to Sovtek, which seems to be the only current supplier.
It has a rich midrange, with enough high frequency definition to reveal details in Tchaikovsky's violin concerto. Both female and male vocalists are well presented, with a good soundstage, and just a bit on the forward side. Madonna's "The Look of Love" has very good separation between the instruments and vocals, with the vocals well-centered and well-soundstaged. Vienna Teng's "The Tower" accentuates her lush vocals. Gordon Lightfoot's "If you could read my mind" brings out his acoustic guitar and solid voice.
Chamber music is similarly well-done. Again, soundstaging is above average, and instruments generally full-bodied. It isn't the last word in detail, but transmits enough nuances in the music to satisfy most audiophiles. Quiet passages are remarkably devoid of any sort of noise, hiss, etc. Impressive, especially for a tube preamp.
The preamp's weakness is in its bass. The bass is on the soft side, and seems recessed relative to the midrange and highs. Despite this, the gong in Copland's "Fanfare for a common man" is remarkably well-defined. But the bass notes in Loreena McKennitt's "Mummer's Dance" are weak, lacking in both speed and heft.
This replaces a Cary SLP-88 in my system, and I consider the Audio Mirror to be the better performer overall. A little less in the bass department relative to the Cary, but the T-61 beats it in most other categories. Not bad for a preamp that retails for one third of the Cary.
Overall, I judge the T-61 to be an excellent value for the money. Its downsides seem to be limited mostly to its bass response, and to a lesser extent midrange detail. But these are truly minor quibbles, particularly for a unit at this price.
Nice work, Audio Mirror.