Which 6sn7 tubes for Rogue Magnum 99

I'll assume you're interested in NOS tubes (and you should be if you're not!).

I don't know which 2 of the 4 matter most, so when I owned the 99 I swapped sets of 4 that I bought on eBay from reputable sellers.

In the realm of reasonably priced tubes, RCA black plates will tend to add some warmth and Sylvania black plates will add some detail and emphasize higher frequencies.

With one set of speakers I preferred the RCAs, with another the Sylvanias.

The 99 responds well to tube rolling and there are lots of options for 6SN7s. Good luck.

Sylvania's are best IMO. Also I use two of one brand and two of another brand this works really well.

Musky1963:

As you look at the front of the 99Magnum preamp, the two tube sockets on the right are the amplification tubes. They are the most important for having low microphonic tubes. They are also the two that will have the most effect on the sound. The two tubes on the left are the mu-follower, or driver, tubes.

Steidlguitars was correct when he said that the choice of tubes will be system dependent.

I tried RCA in the amp side, Sylvania in the driver side: a little too much sibilance in the system for me.

I tried Sylvania in the amp side, RCA in the driver side: way, way, way too much sibilance in the system for me.

I ended up with all RCA tubes.

Sold the Sylvania tubes to a guy who comes into our local shop and who has a darker sounding system - he loved them... and subsequently bought two more for the driver side... still loves them in his system.

Mark told me if you want more transparency or pop which is what I wanted he said with Sylvania GTB's. He was right and I bought a pair relatively cheap and love them. They were NOS tall boys and talking about dynamics. Lusher sounding tubes would be RCA. The GT and GTA's of the Sylvania family do have a little more sibilance as mentioned above but are smooth and detailed.

The NOS Sylvania GTA and GTB tubes that I had in my system were indeed smooth and detailed as Samzx12 described and are absolutely a great tube. I think the sibilance part is going to be system (and preference) dependent. In my system, it was too much for me, but as I mentioned above, another guy in the shop loved them as they transmitted more air and detail through his system than ever before.