Some regular here (Senior Member I believe) swapped to NOS RCA's (I think), and spoke glowingly about it.
My recollection is that Brad thoroughly test tube brands for consistency & tone. I would also suppose that the only rational approach for an equipment builder would be to purchase new tubes which could be pretested prior to installation. This would give consistency with tone & price-point. If he put NOS RCA's in every SMS Classic (& other products), he would then feel obliged to guarantee their performance (Otherwise there might be some number that were DOA.) Not a big deal if they are $15.00. If they're $90 (+), now you've just dropped 1/2 your potential margin.
I certainly don't presume to speak for the guy, but this just makes sense. I'll put a set of Bugle-Boys in there the next time it's out of the rack, and I'll put the stock tubes in a foam box in the back. I think I've got another set of RCA's too, so it might be those.
Wait...Somebody recently did a bunch of sound clips while flipping tubes. Lunasparks...
lunasparks wrote:Rather than launch a new thread, I thought I'd tag along on this one. Link below is to a test of several different sets of12ax7 preamp tubes in my SMS --> MC2105 --> JBL E120 rig. It goes on kind of long but I was trying to hear chords, single note runs, noodling etc.
There are 5 pairs tested in the clip. 1st at 0:00, 2nd at 2:09, 3rd at 4:12, 4th at 6:21, 5th at 8:39
For those interested, I'd be curious to get feedback on which of the 5 you think has the best Jerry tone. I'm trying to find just the right crispiness but I've tested so much I can't hear the difference anymore! 
If a handful of responses come in, I'll follow up with details on the tubes -- I don't want to bias anyone just yet! Let's hear what people like or don't like 
http://www.soundclick.com/player/single ... 53637&q=hi
Very cool, and pleasing to the ears. Thanks Lunasparks!
For your consideration.
Peace
M
