Looking for 5AR4 rectifier tube most like solid state

@immatthewj The argument that the rectifier is not in the signal path is incorrect. The rectifier helps to supply the voltage that's used for the output rail. Noise or dips on that feed are going to affect the sound. Smoothing capacitors certainly help, but they will not eliminate all artifacts of the rectification stage.

With my solid-state Class-AB builds, I've gotten better sound by changing from a TO-220 Schottky FWB to a superior SMD Schottky FWB, so I know it's possible.

What I'm not sure of, however, is whether it will improve the handling of transients. I believe that has much to do with the unit's ability to communicate the rhythmic aspects of the music. Keeping my fingers crossed!

There is no better generator of PRAT than cannabis - in my experience. Even better - it can be "tube rolled’ by variety. This is, in effect, a modification of circuitry.

@boxsoft If it's any help to you, I have yet to find a new-manufacture 6SN7 that sounds any good to me.  Some of them actually generate measurably more distortion than NOS versions.  And with the price of good new 6SN7s today nearing $50 a piece, and given the poor quality control and possible microphonics, you're really better off buying NOS.  Some NOS tubes are unconscionably expensive, of course, but even then they will last longer and give you more listening pleasure than most of the new ones.  The problem, of course, is that searching for your *favorite* NOS 6SN7 can really get expensive. ;-)  By all means, try some different varieties in the Cary, but at some point you may find that tracking down that *one* 6SN7 that makes it listenable to you isn't worth the trouble.  A preamp more to your liking will sound good *regardless* of what "flavor" of 6SN7 you choose.  I'll be interested to see what you discover.

I think that Cary may have give you some bad information. I agree with @rhtowson; there is no reason why you can't run solid state rectifiers in your preamp. While I prefer the sound of tube rectification, there have been situations when I have used plug compatible solid state alternatives. To be honest, while rectifier types and quality (tubes) will make a difference, it's generally not a huge difference. And SS "tubes" last longer and don't change much with use.

Lots of good advise here. Try swapping tubes and/or SS devices and see what sounds and works best for you.

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.