Looking for 5AR4 rectifier tube most like solid state

It’s getting closer to "good enough". We’ll see if the Mullard takes it over the finish line. Otherwise, a pivot to another preamp may be required.

Good luck in those regards.  Let us know how it goes for you.   I have read posts from both sides of the fence on that--rectifier tubes have an effect on sonics/rectifier tubes are not in the signal path & have no effect. My ears are not good enough for me to understand the differences and why I like something or don’t like something. In other words, I might be enjoying my SLP05 more than I ded before I put the Mullard in it, but I just don’t know why that is.

That might be a blessing or a curse, I haven’t figured out which.

@danager that's a really interesting piece 

that would be my first thing to try, if not just replacing the preamp, those are pretty soft and slow

@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.