JJ Electronics T-12AX7-S-JJ Amplifier Tube

The best for pre amp tubes. Sounds are smooth and warm. JJ quality is great.

Works exactly as it should! My amp now sounds brighter, clearer and is more responsive to my playing technique. Excellent tube! Considering 6L6 JJ's for the power amp tubes now!

I have an old DOD VGS50 multi fx pedal from the 90's. I always hated the weak distortion sounds on it. I replaced the tube with one of these and it made a massive difference, surprisingly. The distortion has a lot of bite now.

I've tried a lot of different tubes in different guitar amps and I'm beginning to think it does not make a lot of difference. The only ones I could be sure I was hearing a difference: 1) cheap Chinese OEM tubes that sounded flat, 2) electroharmonix tubes that sounded hot and bright (good or bad depending on what you want), and 3) a NOS amperex Bugle Boy that sounded warmer and mellower - too much so for my taste. These were subtle differences, and all the other comparisons I've made I wasn't sure if I was (maybe?) hearing a difference or just imagining things. JJ tubes are now my go-to. They're inexpensive and reliable. The tone is what I would call "neutral" - not too warm, not too bright, not to hot, not too mellow - tubes that do their job and don't call attention to themselves. If you like your amp and your guitar, just put these in and play. If you need tone adjustments, there are in my opinion better ways to do that. For what it's worth, this realization has brought me into agreement with a well-known tube amp builder/repair guru in my area. He like JJs too.

Great tube choice for the V2 and V3 spots in a Fender Blues Jr. or similar amp. This tube is articulate, well-balanced, and provides pleasant, round low midrange response. In the V1 spot, it's a bit dry and can get shrill in the treble frequencies, yet not as much as similar Tung-Sol or Groove Tube alternatives. Overdrive is soft and natural with decent harmonics, yet it sounds a bit "boxy." Great and reliable option, though better alternatives are available for the V1 slot.

Hot rod deluxe 97 still had the factory fender marked tubes. It's clean sound and the overdrive was too Icepickky. I just didn't like the sound it was making anymore. Tried changing the knobs but it was not where I wanted to be sound wise. I bought this tube for the overdrive channel because some forum blogs said their over driven channel sounded much better to them with this tube in v2 . Also bought 2 other tube to try a selection of tubes some people gave positive comment on . I put JJ 12DW7 in v2 and put a 12AX7EH in V1 I wasn't that impressed. It was better. Still a little sharp on both channels little chimey. They didn't really help the clean channel that much. Tried a t-12AX7-S-JJ in V1 hmmm better..but the clean channel was blaa not a clean sound yet . overdrive sound bearable. Just for grins I put the dw7 in V1 and the 7EH in V2 and Wow my clean channel was super nice now!!!! overdrive ho hum . Put in the 12AX7 JJ tube in V2. Got a warmer sound and steady tone in the Overdrive. The clean sounded a little sweeter. Move tubes around a few more time in v1 v2 v3 . Best combination was JJ12DW7 in V1 JJ 12AX7 in V2 & V3 I left the stock tube in it as i felt the 12AX7EH electro harmex tube made a change in sound although negligible and maybe I was just imagining it but I put the stock tube back into A3 I will keep the 12ax7EH as a spare. It sounded a little chimey to me. Some people maybe able to make this sound into their own. I just wasn't in to it. I almost want to try another DW7 in v-2 . I am looking into finding what would be best in to the V3 socket. The loudness stayed the same. The volume setting sensitive stayed about the same or more touchy. But I'm happy now that the clean is sounding like an acoustic guitar instead of just too busy. Hard to explain maybe some overdrive in the clean. Maybe what they call microphonic. The overdrive is usable ,still undecided. maybe i think it need to sound by my effect processor and not the raw overdriven barky sound. But in a pinch I can make it work. I don,t like a lot of cords and electronic under my feet if I don't need it. The jj t-12ax7-s-jj is a great tube. Sounds better than the stock one and in some tube combination and amp it probably sounds fantastic

Replacement for weak tube in 68 Princeton Reverb. Packed very well. Installed in amp and immediate difference from old tube. JJ’s are solid tubes and never disappoint!

Once burned in, the amp sounds great with this tube. Be aware though that new tubes need a burn in time. Brand new tubes might (as in my case they did) sound a bit scratchy and fade in and out for a while. Stay patient and they'll even out and play nicely. My one-watt amp is nicely quiet now, but puts out a beautiful sound after break-in