6L6s in a stock princeton reverb RI

[Randall]

I'm starting a new thread on the PRRI I have on my bench in case someone can benefit from this info. When checking bias, I noticed it has 6L6s in it,but otherwise looks to be stock. Is this OK? It is sitting at about 32mA, can the tranny handle this?

[Leo_Gnardo]

I'm starting a new thread on the PRRI I have on my bench in case someone can benefit from this info. When checking bias, I noticed it has 6L6s in it,but otherwise looks to be stock. Is this OK? It is sitting at about 32mA, can the tranny handle this?

Old BF & SF Princetons handled 6L6's well. I've never seen a Princeton PT melted down due to the extra amp of heater current. Newer ones? Dunno, time will tell. In one direction you have the tendency for modern "engineering" to build just barely to the breaking point, OTOH modern materials for wire & between-layer insulation are supposed to be better. As far as plate current goes 32 mA isn't out of line at all, seems just about right for 6L6. I generally run 'em at 30, just a whisker away.

[Randall]

Here is another wrinkle, customer reports amp sounded funny at a church gig. he turned around and saw the pilot light out. After a bit the light came on, and the amp was fine for the rest of the afternoon. Makes me wonder if the PT was stressing with the 6L6s in there, but I don't know if a PT can even go out and then come back like that. Maybe a temporary loss of power at his outlet? At any rate, I convinced him to go with a set of JJ 6V6s. He didn't even know he had 6L6s in it.

[Leo_Gnardo]

Here is another wrinkle, customer reports amp sounded funny at a church gig. he turned around and saw the pilot light out. After a bit the light came on, and the amp was fine for the rest of the afternoon. Makes me wonder if the PT was stressing with the 6L6s in there, but I don't know if a PT can even go out and then come back like that. Maybe a temporary loss of power at his outlet? At any rate, I convinced him to go with a set of JJ 6V6s. He didn't even know he had 6L6s in it.

It wuz the spirits... Perhaps best for all to go JJ 6V6, plenty enough power and they are tougher than the rest. Of course a thorough check of all filament connexions is in order with the symptom described. Seen lots of old Fenders with loose filament wires at the pilot and tube sockets as well. If the old ones can do it, so can the newer ones. There's also loose pilot sockets, corroded lamp bases, but they don't cause the power to drop out. Also on occasion, the pilot wire connectors are positioned so that they're shorting to ground or nearly so. All that grief just for a dang pilot lamp.

[Tom Phillips]

... I convinced him to go with a set of JJ 6V6s. He didn't even know he had 6L6s in it.

A good choice IMO. 6L6s will sound different but not necessarily "better" and they won't allow the amp to produce significantly more power, if any. The higher power amp gain structure resulting from the use of 6V6s is one design feature that gives the Princeton Reverb and the Deluxe Reverb and other 6V6 Push Pull amps the performance that people love.
Rock On,
Tom