12AX7A preamp tubes - ribbed vs smooth plate

The Mono amplifier uses 4 12AT7 tubes and while four seems a bit much for rectifying (ie converting AC to DC) maybe two are devoted to this worthy cause and then it leads to the question what are the other tubes used for . I thought preempt tubes were a way to describe use of this tube within an amplifier (ie taking the week analogue level signal from the pre-amplifier and turning it into a stronger line Signal) and is this also considered to be a signal tube?

I thought preempt tubes were a way to describe use of this tube within an amplifier (ie taking the week analogue level signal from the pre-amplifier and turning it into a stronger line Signal) and is this also considered to be a signal tube?

I’ve never made any claim whatsoever to be an audio/electrica/tube guru, so maybe I’ve been wrong all these years, but I always thought of the tubes in a preamp (or the preamp section of an integrated) as being the "preamp tubes", and then all of the tubes in an amplifier, including the smaller input or driver tubes, as amplifier tubes. For example: In my amp, I have always considered the pair of 6922s and pair of EL84s that are in front of the dozen EL34 output tubes as all being amplifier tubes. And I have then also considered the six 6SN7s in my preamp as the "preamp tubes." But like I said, maybe I have been wrong about that.

As far as "signal tubes", technically, I guess they would be any tube in the signal path? Although I guess that when someone says "signal tube" maybe we usually think of the smaller tubes in the front of an amp or the tubes in a preamp?

I don’t know for sure, and here’s to hoping someone will educate me, and as I typed previously--I guess it doesn’t really matter what you call them (although it may be confusing if we all call them by different nomenclatures).

I grey up in the 70s and early 60s type smooth plate was more preferred.

siemens isat least on paras Tele  . 50-60s preferred for both,  early 70s, no 80s.

check Andy at vintage tube services. The most knowledge on tubes period !

Brent Jesse audio has been around also ,as well as vacuum tubes  dot net 

I have tried Smooth plate and Ribbed plate Tele's in my CAT preamp, much prefer the Smooth plates. The Ribbed plates are a little brighter and tend to be less resolving. Perhaps in a different position, or component, this might not be the case??