@jb1
I ran Genelex Gold Lion reissues in my c2300 preamp and pair of Mc275s for 13 years. I do not have a C1000. They should be good tubes to run with your McIntosh C1100. You can easily replace them yourself. Just take the top cover off. The 6 facing the cover will have a clamp securing them that you also have to remove (2 screws). The 6 standing up ones should just pull out. When pulling them out, pull slowly, and wiggle a little bit, just take your time. It is easy. I like to spend the extra money and get the tubes perfectly matched to each other. Not required, because in this preamp, the tubes tend to work in quads, but, I would ask the vendor to match all twelve tubes together anyway. I found this chart online with AI, so, at a minimum, I would buy well matched quads. Also, just because AI says this is the story does not mean it is correct. So, please validate.
Stage Tube Type Quantity Purpose
Phono Stage 12AX7a 4 Handles the high-gain amplification required for turntables.
Line Stage 12AT7 4 The primary gain stage for standard inputs (CD, Streamer, etc.).
Line Stage 12AX7a 4 Acts as the output buffer/driver for the line stage.
Note: Pics of your C1000 with the top off can be found with google search. You will see how easy it is. Note: I tube roll now, and I like vintage Telefunken smooth plate matched pairs in my phono stage and line stage of my C2300, but, it is not easy to get NOS ones that are well matched, and my C2300 only uses matched pairs for each stage, not matched quads like your C1100. So, it may not be worth the effort for you. You should be very happy with the matched Gold Lions.
