Originally Posted by plexipaul

My pick for my 100 watters:

V1: Since V1 has the most effect in the preamp section I want the most low noise tube with the most amount of gain for a reasonable price. ECC83S and TungSol 12AX7 apply on these criteria. Although TungSol 12AX7 has a tad less gain compared to JJ ECC83S it is a more musical tube and more pronounced in bass, mids and highs. For that the TungSol 12AX7 is my favorite for V1.

V2: mainly tone shaping; I have JJ ECC83S in my JMP and a old Mullard ECC83 in my SLP. Both tubes tame some of the highs (i work with M25 Greenbacks).

V3: Phase Inverter; As of today i can confirm the hype about balanced phase inverters, at least this is the case with my Marshalls. I don`t know about other amps. Today i`ve put in Philips NOS JAN GE 5751 in both amps. They do not only make the tone tighter (bass in particular) but also sustaining notes sound lots more musical compared to other non-balanced tubes such as TungSol 12AX7, Marshall ECC83 (white label= chinese), Mullard ECC83, JJ ECC83S and JJ AT7 i`ve experimented with.