Looking for 5AR4 rectifier tube most like solid state

First of all, I used a Cary SLP-98P for a couple of years but I got tired of the thick, sluggish sound. I now use a 6SN7 Aikido preamp of my own build, very similar to what Don Sachs was providing before he retired from that business and moved to Spatial Labs. That in turn was based on the Tubes4HiFi SP14 octal Aikido preamp. The Aikido circuit is much "faster" and more transparent than the Cary, plenty of rhythm and pace.

Secondly, I would NOT mess with solid state replacements or different types of tube rectifiers at the risk of voiding your Cary’s warrenty or worse, damaging it. IMHO the Cary sound is determined by the way they configure the 6SN7, and also the type of output caps they use. A lot of folks like that sound but like you, I found it unsatisfying, especially once I heard the Aikido-style preamp.

You COULD try a genuine Mullard GZ34. They tend to be "faster" and a bit more lively on top than most others. A current-manufacture Chinese or Russian 5AR4 will, IMO, NOT get you what you are looking for.

If you want to keep the naturalness and linearity of the 6SN7, I’d suggest a used Don Sachs SP14, or the Linear Tube Audio MicroZOTL or the new Velo, if that’s more within your budget. Also look at the Icon Audio Pure Valve. Another option might be the Black Ice F360, which also uses the 6SN7. That’s my .02. ;-)

ETA: I forgot to mention that the Tubes4HiFi SP14 is still available, and at a very good price. It’s not as tricked out as the Don Sachs version, but it’s a VERY good preamp for the money, one of the great bargains in high-end audio IMO.

Thanks, all, for your recommendations! I’ll start with that NOS Mullard, and decide whether to continue and swap the driver tubes, or to give up and move to another preamp.

FYI, the Mullard is an F32 4 Notch dual halo GZ34/5AR4, Coded F32 B3C1 (Translates to Blackburn plant, 1963, March, 1st week).

I've had a SLP05 for a few years now (at least three, if I remember correctly) with the Ultimate Upgrade, and I love the sound of mine.  I'd go so far to say as it may have been the most significant upgrade I ever made.  Unlike you, I am not finding mine to be sweet/warm/colored . . . if anything I find it to be a tad more neutral than I might like, but the detail and imaging I hear with it in my system makes up for that (for me).

I have rolled a few rectifier tubes and I, honestly, cannot say for sure I heard any difference.  I've had a Mullard 5AR4 in there for a while now.  The tubes I've heard the biggest difference with are the two balanced input tubes.  I've had a few I liked (a pair of KenRads a generous individual bestowed on me) a pair of Tunsol VT231s I liked a lot, I loved a pair of black glass RCA VT231s for the precise detail that I thought they brought out.  At the moment I have a pair of "'52 Sylvania Bad Boys" (6sn7s)  (that were described to me as the "Iron Fist") in those sockets and as of now they are my favorites.  Another generous individual turned me on to those two Sylvanias  also gave me a pair of National Union 6F8G that he described as "The Velvet Glove" and I like them, but for different reasons than I like the "Iron Fists."  If  you decide to try 6F8Gs, you will need adapters.

Good luck.  I hope you can get that pre to do what you want it to do for you.  People have different goals and expectaions from their gear, and, as I just typed, I hope you can meet yours.  

. . . I just thought of a similar thread (questions about 5AR4 for a SLP05) a while back ago.  It may or may not be helpful to you, so I'll post a link to the discussion:

5AR4 for Cary SLP05 thread

Thanks for those recent responses. I haven't got that Mullard rectifier yet (picking it up this weekend), but someone came by with some NOS Sylvania 6SN7 GTB. That was a big boost forward, beyond the Electro Harmonix (Gold in the Input, and regular in the Driver).

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.