Krell FPB 300cx vs FPB400cx

I have a 300c (predecessor to the 400cx, not the 300cx) and have been wondering about the upgrade path for my amp to the 400cx. In my search, I think I read somewhere that the power supply of the 400cx is significantly more substantial than the 300cx. Perhaps this contributes to what Stevecham experienced.

Dbld: Yes I believe that is part of the answer. I also read that the circuit that keeps the amp biased into Class A was also upgraded so that this happens in extrememly short time frames and stays there for 9 minutes before resetting. The toroidal transformer in the 400cx is considerably larger when compared to that of the 300cx. My impression agrees with your suggestion that some of the sonic improvements I heard were due to the "beefier" power supply. Have you talked to Krell about the upgrade? Very friendly folks.

Stevecham: Not yet. I have had a HTS 7.1 for a couple of years now, and have really liked it. It is very much unappreciated in most forums, but I have done some side-by-side comparisons using the two-channel analog pass-through, and it keeps coming out on top.

I just bought my 300c used here on AgoN. I'll need to wait until this busy holiday season calms down before pursuing an upgrade in earnest. If I had better timing, I would have gone for the Audio Pimp's 400cx. It would probably be cheaper for me than upgrading a 300c. So for now I am just kicking the idea around and gathering info (tire-kicking).

I have had occasion to speak with the Krell folks in the past. They have always been very forthright and helpful.

Dave