Cary Audio SLP 05 PreampWhat tubes are you using?

I recently purchased a used Cary Audio SLP 05 Preamp from a fellow Audiogonmer. It did not come with the original tubes.Instead supplied were some NOS Raytheon 231, and Sylvania 231.

I have also bought a pair of NOS Ken Rad VT-231 tubes, and a few of the Sylvania short bottle.

I have changed the rectifier tube to the Phillps GZ 34 metal base mini watt made in Holland.I have also installed the HiFi fuses.

Any other suggestions as to tubes for this Preamp, there seems to be so many ?
Interesting that you're mating this with a Pass Labs amp. Stereophile's
measurements section in their review of the SLP-05 suggests that a match with
an amp with relatively low input impedance, like the Pass Labs, might not be
ideal due to the Cary's high output impedance at certain frequencies.

What's your take on the match? How's the tonal balance of your system?

Regarding tubes, Kevin Deal of Upscale Audio is a dealer for Cary, and he has
substantial experience with 6SN7 tubes. He'd likely have some specific
suggestions (of course with an emphasis on those he has to sell).
I'm currently using the Pope Hollands. I've tried a bunch of them though. It's all a matter of what is most important to you. The rectifier that you've chosen is the best one IMO.

Good Luck with it.
I don't own an SLP-05 but would love to.
I understand that the N7s on the extreme right when facing the pre are for the headphone amp. I would roll tubes to my hearts content. I have tons of N7s and use good "cans". I might use that section to characterize some of the tubes I had. (If I tried that it would be a quite a long while)
If you don't have headphones or even care about that circuit then use "place holder" 6SN7s, perhaps the stock tubes, which are likely the Sino brand and aren't very good. Or if possible leave them out altogether.
The NOS/OS tubes you have are highly desirable. As such I might move the pairs around to find the best order for them. I would inlude the Ken Rad in a gain stage, if quiet enough ,for added bass energy or in a driver stage. If you are afraid of that, then call Dennis Had, to ask what he would do.
If you know what each pair is good at, knowing the sonics of the tubes you have, then you can make, at least, semi-intelligent choices.
Good Luck,
Sounds like fun.
In general is it ok to have many different combos in place at the same time.
They would all be 6sn7 or 231 ?

Thanks for the responses so far.

Tvad, the tonal quality seems to be ok , but each tube seems to change something a little bit. What should be the weaknest with the Cary/Pass Combo ?
My complaint so far is that I can only use about the first third of the Cary's Volumne control.

Jtwrace, I have heard about the Pope tubes but it seems they are only available thru Upscale Audio and he will only sell to his clinets of his equipment. But, I am curious, how does the Pope compare to the other tubes ?

Mechans, I have also ordered a pair of Tung Sol Round Plates to try with the Cary.
The Stereophile test measurements suggest that there might be rolloff in the treble and bass extremes, although Atkinson states the preamp is happier with low input
impedances than with very high input impedances (as found in BAT amps), so
maybe the rolloff isn't noticeable in balanced mode with the Pass Labs ~20K
input impedance.
Congratulations on owning a great preamp. The Sylvania short bottle 6SN7W are great tubes. I would also try the 1578 Russian 6SN7 tubes to add more air and space between amazing sounding tube.

Disclaimer: I do sell tubes on Audiogon.
Yes, the Popes have gooten almost impossible to for sound I still like them better then the RCA/Sylvainia GTB's. I would like to try some Tung Sol RP and some Russian 1578's. The cost has just gotten out of control on these though. I'm so happy with the Popes (and have many of them) that I'm inclined to stick with them unless I find some NOS Russian/RP's on my frequent search.

my amps imput impedance is 100K and the SLP-05 and Clayton match is great IMO.
One day later, and the SLP-05 is for sale?
as to the range ...I know what you mean. I tried the slp-05 with my x250.5 and same's due to excessive gain in the system (pass ~30 dB gain, slp-05 ~8 dB gain) with typical ~5vrms balanced digital sources. The 8dB from the Cary is actually less than the normal >10 dB gain active preamps. Unless you install signal robbing attenuators you are screwed and have to live with it...or sell it! Pass X10 and X20 now have closer to unity gain --user selectable.


who's selling the SLP-05?
The OP.
Yes, its true. I am selling my Cary unit. As beautiful as it is there is a impedance mismatch with my Pass Labs X 350.5. Couldn't quite put my finger on it, thought trying different tubes might be the answer.

After reading Tvads comments I started to do more digging. Sure enough, I found several reviewers who commented that the Pass Labs X 350.5 does not work well with tube preamps.

So, I have a choice, to sell the Cary I just bought or sell the Pass Amp.
The Pass Amp has been good , and weighs 150+ lbs to ship. The Cary, I really dont know its potential, so I am selling the Cary.
Too bad. I really like my SLP-05. With my X-250 I used a X-1 pre and thought it was great. Personally, I really like the Tube pre with SS Class A amp combo though.
FWIW, there are a few tube preamps that will work with the Pass Labs. I own
one: Lamm L2 Reference (actually solid state with tube power supply).

The Modwright 36.5 has an output impedance that would work well. I've
never heard one.

I know the Atma-Sphere MP-1 MK III works very well. I actually liked the
combo very much, but the tube maintenance was an issue for me.

I haven't determined if an ARC Ref3 will work or not. Stererophile's test
measurements suggest that bass might be rolled off, and they recommend an
amp with greater than a 20K input impedance (which the Pass Labs has).
Don't laugh, but actually I like the Electro Harmonix 6SN7 better than most other tubes in the SLP 05.