Yes - at least more volume compared to the EH and reissue Tung Sols I've tried.
IMO, they are pretty damn close to a 7591A type sound - those were the tubes most commonly used in mid-late '60s blue check Ampeg combos. A cleaner sound, more headroom, but still has the warmth of a 6V6. I think they are really great sounding tubes in certain amps.
They may lean towards a 6L6 sound, and give you a bit more volume, but bear in mind that they're still decidedly 6V6s. Damn nice ones at that, and not just for new tubes. In the right amp they can be downright great.
I have one in my SF Champ. Very rugged, my amp puts 390V on the plate stock for something in the range of 18W plate dissipation (calculated from cathode current) and it's surviving. As others have mentioned, slightly cleaner/later breakup than the newer EH I had been using. Still very much a 6V6 tone. I actually tried a 5881WXT and the tone was not nearly the same.
Why not ? Run it into an 8 ohm speaker load (doubled) to put an 8k plate-to-plate load (primary OT impedance, if you prefer) on the JJ 6V6's.
There might be enough range of adjustment in the bias circuit to bias the JJ 6V6's without changing the resistor.
I haven't tried this in my BF Vib Reverb replica but it sounds like a pretty good idea----good enough to try out, anyway.
I like the JJ 6V6's--- a guy brought me a much modded '68 Deluxe Reverb recently, said it was breaking up too early----- i straightened out the circuit to his liking and he left with a big smile---this one already had JJ 6V6's in it so i didn't need to recommend them to him.
Another guy is running JJ 6V6's in a 25 watt version of a modded Marshall 2204 that i built a couple of yrs ago--- i just put a Metro Zero Loss FX Loop into it for him---he runs the amp pretty much flat out and he's very happy with the tone.
I have plans to build a JJ 6V6 x 4 version of a Tweed Fender circuit in head form---not sure exactly what circuit/configuration yet but this should be a great sounding amp---not an orig idea, but a good idea.................................gldtp99
yup , only the jj's , they work great , they cut the headroom down a little(still really loud!!!!!!) , tried it to get closer to the sweet spot without killin the room , just got a brake lite so when the jj's die i may go back to 6l6's but honestly they sound great...........
I have four of them in my Silverface Twin, in fact they're cathode biased as well. Been running it this way for almost a year with no problems. Of course I took a number of precautions: doubled speaker impedance, big screen droppers, and some substantial resistance in the power supply. It gets a little warm (due to the cathode bias), but everything is operating within spec. I tried to convert it to bias mod tremolo, but unfortunately this created a heart beat effect that I couldn't get rid of, so it's going back to the opto trem soon. Also has a half power switch that lifts the cathodes of two tubes and disconnects one of the speakers. Best sounding Twin I've ever heard.