I just plugged mine in again while my Mark Levinson was out being repaired, and I have to say it still sounds great! (maybe better than the ML - maybe not quite as detailed but a nicer fuller warmer sound). I had attempted to have the slide switch volume control replaced a few years ago, but the shop was unable to find a slide switch with an audio throw and the one they used goes from quiet to deafening with about a quarter inch of movement. So if anybody has a replacement for that I could use it. Otherwise mine is holding up pretty well. I primarily use it as a phono preamp these days since my Mark Levinson didn't have one built in.
Theta Stereo Preamp suggestion
I have found Theta Tube Preamplifer in the used market. I have never known that Theta made tube preamplifier also. Or is it different company from the Theta Digital company? Any ideas or information regarding this tube preamplifier is welcome. I am worried that if I bought unit, it will be difficult for me to find the service since I cannot find the company on the Internet.