Hi. I bought a used C220 from Audio Classics almost 2 years ago. I can't compare it to anything except the Conrad-Johnson PV-11 (w/phono) that I replaced with it. There might have been a touch more of the "tube magic" with the C-J and the C-J might have been a tiny bit quieter, but the C220 stomped all over it in terms of extension into the bass, soundstage width, ease of use, control flexibility, detail retrieval, and frequency balance. Note that I upgraded to Mullard re-issue tubes, and the C220 became much quieter, a touch warmer, and the highs became smoother, more detailed, and sweeter.
Except for the C2300, my dream preamp, I think I am done as far as preamp upgrades go. I really like this preamp. If you are buying new, try to arrange a home trial with the dealer, so you can hear for yourself. If you are buying used, I can't say enough positive things about Audio Classics. They offer a 7-day return option, so if you're unhappy you can ship it back. Plus, their customer service is among the best in this business, IME.
Except for the C2300, my dream preamp, I think I am done as far as preamp upgrades go. I really like this preamp. If you are buying new, try to arrange a home trial with the dealer, so you can hear for yourself. If you are buying used, I can't say enough positive things about Audio Classics. They offer a 7-day return option, so if you're unhappy you can ship it back. Plus, their customer service is among the best in this business, IME.