Cary Audio SLP-5 Preamp Tube Replacement.

I do not have the Golden ear but I do have a SLP05. If you are using RCAs and NOT using your balanced inputs, you will get absolutely nothing by replacing the two balanced input tubes. As a matter of fact, the reviewer who reviewed the SLP05 for Stereophile wrote that the preamp will atually operate fine without any tubes in those sockets (3 and 6). I have not tryed that so I am not confirming that. If you are not using the headphone out of the SLP05, no need to replace 7 and 8.

I, personally, am using the balanced ins and outs of my SLP05 and I have heard significant differences by only rolling tubes in those sockets (3 and 6). I have had the good fortune of a couple of very generous people giving me a pair of NOS tubes and also one who sold and gave me several pairs of slightly used vintage 6SN7s and VT231s and 6F8Gs that I have been rolling in those sockets, but since you are using your RCAs, I won’t go into that yet.

I would suggest that you try your SLP05 using balanced cables and see what you think, and if you like it, then consider rolling tubes in 3 and six.

As far as 1 through 6, I only recently pulled the EHs and put in JJs 6SN7s. I started by running all six tubes with JJs (with no vintage tubes) and I felt I heard more life with the JJ 6SN7s than with the EHs. Then I put a pair of ’52 Sylvania "Bad Boys" in front of the four JJs and it was one of those oh-em-gee moments. As I put more hours on the JJs, began to enjoy the experience any more.

(Tonight I actually replaced the ’52 Sylvanias with a pair of National Union 6F8Gs and adapters, but I never got beyond verifying that I had a signal from both left and right channels tonight, so I cannot report on that just yet. The NUs did come highly recommended.)

As far as the Psvanes you listed, I have no experience with them. A member who goes by @xcool (if I remember correctly) has a SLP05 and again, if I remember correctly, he put in some expensive Chinese 6SN7s called "Linlis"? But I am not positive about the brand name. I got the impression that he liked them.

As far as the power supply, did yours come with a Sovtek 5AR4 rectifier tube? You may actually hear an improvement by upgrading that, although not everyone agrees that the rectifier tube will have a noticeable sonic effect. Regardless, it would probably be a good idea to at least keep a spare on hand.

The Linlai E-6SN7's were my tube of choice in the SLP-05.  As @immatthewj noted you only need 4 of them if you aren't running balanced.  My SLP-05 sounded a bit better with balanced ins and outs but not as good with mixed inputs but your experience might be different.  I just bought my E-6SN7's off Aliexpress.  No need to pay extra for the nonsense Premium Vacuum Tubes spouts to justify more than doubling the price.

My friend bought a tube preamp and tube phono stage, brought them here for a listen. I was quite surprised how much the sound changed when he tried the alternate rectifier tube the maker had included. Quite obvious difference, not subtle.

I bought a pair of 6sl7s, hated them, returned, tried different ones, love them. Again, obvious, not subtle.

Seemed like a bigger difference than I have experienced when changing 12ax/12au's

Thank you for your replies my friends. So, let me get it right, I just need to replace 1, 2, 4 and 5 slots as I only use unbalanced cables? Also @pinwa Did the Linlai tubes fit and how do they sound in SLP5? 

I really appreciate your giving time to my queries. Thanks.