Small or big tubes/valves for pre amp ?

@grey9hound - I’ve been using 1940s, Tung-Sol(round plate/JAN CTL/VT-231) and Sylvania (6SN7W/JAN CHS/tall bottle/metal base) tubes, in my monoblocks for a couple decades(one each per amp). I’ve kept a stash of bottom-gettered, 1940s, Ken-Rads and Sylvanias, for back-up. They were specifically chosen, after listening to every one of the the top fifteen tubes mentioned on the following list, for their low noise/microphonics and lack of excess warmth/sugary glaze. Regarding Sylvania 6SN7s and Bass: that’s EXACTLY for what the tall bottle, metal-based Sylvania 6SN7Ws are known(slam). I’ve found all the(early) Sylvanias, well balanced from top to bottom, except for the short bottle 6SN7W, which(to me) was unlistenable. (http://www.dehavillandhifi.com/6sn7_vt.htm)

"Do your amps use one or two 6SN7 tubes ? I am confused about that" As I stated: I’ve been using 1940s, Tung-Sol(round plate/JAN CTL/VT-231) and Sylvania (6SN7W/JAN CHS/tall bottle/metal base) tubes, in my monoblocks for a couple decades(one each per amp). Yes, that’s one JAN CHS and one JAN CTL("one each per amp"), at the same time. I collected a couple pair of the metal base and a couple pair of the slightly later(sans metal), tall bottle 6SN7Ws(which to me seem equivalent), before either became so rare. If you’d read the observations, contained in the 6SN7 comparison article, the author mentions the following: "It appears combining tubes like the VT-231s as voltage amplifiers and 6SN7Ws or 6SNGTA/GTBs as driver tubes you gain the strengths of all. Using one type seems to accentuate the tube’s weaknesses." I’ve found my Sylvanias very faithfully pass("well balanced") whatever information I feed them(including the bottom-gettered VT-231s). I chose my favs, based on my preference for tubes that don’t editorialize. They all(Sylvanias, Tung-Sols and Ken-Rads) also passed more ambient information, resulting in a wider/deeper sound stage, than any of the others I tried. Happy listening!

Given the number of circuit designers, over the decades, that have chosen to utilize both nine pins(ie: 6DJ8 iterations) and octals(ie: 6SN7s), and the excellent results, that have been attained with both choices, has led me to believe that blanket statements are worthless. They only serve to prevent some from experimenting on their own, to find their personal preferences. Regarding Sylvanias and, "having Bass": I don’t want my tubes to, "have" anything of their own, but- to pass what’s presented them, without leaving their own footprints. The author of the 6SN7 comparison, made this statement(his first sentence): "Let me stress that the optimum tube for your system will depend on your equipment and how your ears judge the tube’s ability to reproduce live music." It seems some miss(or choose to ignore) those very salient(and universal) points(circuit variations/subjectivity).

@mulveling-  Mixing tube types in a circuit, to reinforce the positives of each, doesn’t ONLY apply to 6SN7s, but works in most any application.

"...opinions..."   Exactly!

Just glad I stocked up on all my favorite 6SN7s and early 60’s, grey plate/shield, Siemens CCa’s(the CDP takes six), before they became unobtainium!  Again: Happy listening!