@danager +1 on the space tech lab super rectifier, I own one and it makes a profound difference with my preamp. I don't know exactly why it makes such a difference, but it does, if I want it to sound more like solid state I just roll in a couple 3B22 or 3B28 tubes, if I want more tube sound I just use 300b or 2a3.
Looking for 5AR4 rectifier tube most like solid state
I have the Cary SLP-05 preamp (with the Ultimate Upgrade), which sounds exceedingly good in most respects. Unfortunately, it's sorely lacking in rhythmic excitement (what various British companies call Pace, Rhythm and Timing, or PRaT).
I suspect that the 5AR4 tube rectifier is at least partially to blame. In general, tube rectifiers exhibit "sag". This helps some aspects of the performance, but is likely dulling transients that are needed to create faster dynamics (e.g. percussive envelopes).
Cary has told me that I cannot insert an equivalent solid-state rectifier, as it would require a power supply redesign. Instead, I'm hoping to find a 5AR4 tube that mostly closely behaves like a solid state rectifier. I don't want it to be warm, or smooth, or anything like that. This preamp already has an overabundance of those qualities. Instead, I want it to be fast, dynamic, rhythmic, and exciting, with a real sense of "boogie".
Any suggestions?