I’ll take the middle road. If you don’t have a fetish for blue meters, the C47 offers a lot of what the more expensive Mcintosh preamps have, albeit with fewer inputs and less bling. As @gphill mentions, you also get an onboard DAC (so-so, IMHO) and phono stage (not too shabby, also IMHO) so you can play around with different combinations if you are so inclined. You also get tone controls which are not all that common these days. I think you could do a lot worse.
However, I would be more likely to recommend the C47 in an instance where an amp was more difficult to drive. I’ll put Mac’s in this camp, for the most part. I will agree with @D2girls that the C47 might not bring anything special when paired with the Carver.
The good news is that since your TFM 45 needs only 1.5V to bring it to full power and it has an input impedance of 115 K ohms, it should be pretty dang easy to drive and mate well with a host of different preamps. You might find a tube or hybrid pre for significantly less than $3,500 that could sound pretty sweet with the Carver.
However, I would be more likely to recommend the C47 in an instance where an amp was more difficult to drive. I’ll put Mac’s in this camp, for the most part. I will agree with @D2girls that the C47 might not bring anything special when paired with the Carver.
The good news is that since your TFM 45 needs only 1.5V to bring it to full power and it has an input impedance of 115 K ohms, it should be pretty dang easy to drive and mate well with a host of different preamps. You might find a tube or hybrid pre for significantly less than $3,500 that could sound pretty sweet with the Carver.