Cary SLP98L Tube Rolling

You need a pair of Raytheon VT-231s in the rear sockets. The front sockets will then be able to flavor your music/tone. For a full juicy presentation, try RCA VT 231s(lighter), or Sylvania VT231 (fuller). Best neutral tube is the 1952 Sylvania 6SN7GT, or TungSol round plate 6SN7GT.
Sylvania 6SN7W is a great tube, and very dynamic.

The Sylvania are very popular so are the Raytheon particularly in the rear sockets. I am currently using National Union Grey Glass and have found them to be the best 6SN7s to my ears in my system. I'd try the Sylvania first since most people seem to prefer them. I have several pairs if you want to try some.

I recently sold my SLP-98L, but tried a number of tubes in it while I had it. One person you may want to speak with is Andy at Vintage Tube Services. He knows this preamp well and can make some nice tube suggestions. One suggestion he made to me is to use 6SN7GTA or GTB tubes in the buffer stage (rear sockets) and use 6SN7W, WGT, GT or VT-231 types in the gain stage. He said the buffer stage had a tendency to wear out the W, GT, and 231 types quickly. This advice worked well for me. Some of the combos I tried were:

Raytheon VT-231 (late '40's)/Sylvania 6SN7GTB (early '60s)
Raytheon VT-231/Tungsol 6SN7GTB (early '60s)
Sylvania 6SN7W (black base short and tall bottles from the late '40s)/Sylavania 6SN7GTB
Sylvania 6SN7WGT (early '50's)/Sylvania 6SN7GTB
Sylvania 6SN7WGT/Tungsol 6SN7GTB
Sylvania 6SN7GT ('50s Bad Boy tall bottles)/Sylvania 6SN7GTB

All of the combinations were interesting and it was a fun process. I would have to say the Raytheon was an excellent tube, right up there with the "W", but at a much lower price. I liked the combo with the Sylvania GTB better than the Tungsol GTB. An excellent combo, but a bit expensive is the Sylvania "W" (I preferred the short bottle as they were less microphonic) with the Sylvania GTB (the GT/GTB was nice too). The Sylvania GTBs I bought were from Tube World and Brendan has an excellent selection of cryoed tubes which is what he sold me. The Sylvania WGT is a nice tube and in this case I liked it better with the Tungsol than the other Sylvania GTB.

Here is a link I used to review 6SN7 type tubes and their characteristics:

http://home.att.net/~chimeraone/6sn7sound.html

One thing to be aware of is that 6SN7 tubes are getting rare and finding good, non-forged, low microphonic tubes are difficult and expensive. In my opinion the new production versions don't hold up, although Cary swears by the Chinese ones they use and maybe rightfully so as some designers are voicing their products to specific types of tubes by specific manufacturers.

Also, email me if you like, since I no longer own the SLP you might be able to convince me to sell a couple of pairs to you.

I had an SLP98 with phono. My advice to you, unless you have the direct version, is to change your capacitors from the Kimber or the Cary oils to Teflons, REL TFT recommended (that is what I used so my recommendation). Will take a while to break in but when the do, great. This is a world class preamp crippled only by the caps used in the stock versions. To me, the improvement here was much much greater than changing tubes. For tubes, I used Sylvania chrome domes and was very happy with the combo. Better than stock but not better than changing the caps. Good luck.

can anyone suggest a reputable vendor for the tubes? i see a lot on on-line dealers, but i don't know who offers good service and good quality.

Vintage Tube Services - Andy Bouwman
Tube World - Brendan Biever

I have had excellent results getting 6SN7 tubes from both these sources.

i received more than one email from people who told me that tube rolling on this pre amp is not worth the money. they said that the difference in sound quality is so minimal that it is not worth the time and the expense.

anyone have an opinion on that?

In my system it was well worth the time and expense. As I said in a previous post, the Cary is most likely voiced to the Chinese 6SN7s, so they won't sound horrible, but in my system when I swapped in excellent NOS 6SN7s it was clear to me that there was more than a minimal difference.

There is only one way to find out. Give it a shot and hear for yourself.

As for using Raytheon-VT 231s in the Cary, which type is more preferable : flat plates or t-plates?

Well worth tube rolling, and the "F1" version (direct coupled with oil caps) is definitely the way to go. A true giant slayer at reasonable cost.