2. amps-preamps
  3. 190729-187807

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?

128x128boxsoft
boxsoft's avatar
boxsoft OP
7 posts
 

Yes, I was a bit surprised when they claimed that changing the rectifier would require a complete power supply redesign. I've designed power supplies for many solid state amps myself. SS rectifiers have a lower voltage drop, so the rectified voltage would be higher. Consequently, the smoothing caps would have to accommodate the higher voltage.

I guess that higher smoothed DC voltage would be passed along to any regulation circuits, and potentially require more heat dissipation. (I have no idea what's in place in the SLP-05.) If there is no regulation, then the higher voltage would be passed along directly to the rest of the circuitry.

Therefore, I wouldn't feel comfortable trying a SS rectifier without the blessing of Cary.

br3098
994 posts
 

Therefore, I wouldn't feel comfortable trying a SS rectifier without the blessing of Cary.

Understand. But the tube plug-compatible SS rectifiers are designed to be direct replacements. I have tried them in many amps and never had a problem. They run much cooler than any tube and I haven't noticed any voltage differential, compared to the compatible tube. But maybe the Cary circuit is more sensitive???

boxsoft's avatar
boxsoft OP
7 posts
 

Thanks, @br3098 . I haven't had a chance to try the Mullard yet. If I'm still dissatisfied with that, then I'll ponder whether to try a plug compatible one, or to start looking for another preamp.

More to discover