Electro-Harmonix 12AX7EH Preamp Vacuum Tube, Single

This Russian made 12AX7 tube was installed in my Ibanez TSA15h amplifier in the first preamp slot, replacing an old J/J 12AX7 tube.Installation was straightforward and it seated properly without any issues. Once installed, the amp powered up normally and operated as expected.In terms of sound, the change is noticeable in a good way. The amp feels a bit more responsive and has a slightly smoother overall character compared to the older J/J 12AX7 tube I replaced. Nothing extreme or dramatic, but a clear improvement in clarity and feel when playing. The distortion is a little better with the EHX over J/J. I also run a 12AT7 in preamp slot 2 so I get a slightly cleaner tone.Build quality on the tube itself appears solid. It arrived in its own box with a layer of bubble wrap, which was good initial protection. However, Amazon shipped it in a soft bag instead of a box, which was not ideal for something fragile like vacuum tubes. Fortunately, it still arrived undamaged.So far it has been stable during use with no unwanted noise, microphonics, or intermittent behavior.Overall, this is a reliable replacement preamp tube that performs as expected and works well in my amplifier. It is a straightforward upgrade or replacement part that does its job without any complications.10/10 it’s worth every penny. EHX always hits it out of the park with their products.

This is the best sounding preamp tube currently in production, full stop. I don't know what they're doing differently with these because it looks like all the other ones, but it has way better bass response, and overall more lively frequency response and just much wider clarity. I was really surprised because Electro-Harmonix tubes don't have the best reputation in terms of tone or consistency. I've since replaced almost all of my preamp tubes with these, and man oh man what a difference. If you're not happy with how your amp sounds, put one of these in at least V1 and you should IMMEDIATELY be able to tell the difference.Caveat is: I have no idea how they sound in an overdrive channel. I don't have any amps that switch between clean and dirty. I would have to imagine it'd sound good there too. They are also really good PI tubes, I've got one in my Music Man (the ones that have the tube power section, but solid state preamp section, but with a tube PI) and it woke the thing up in ways I did not expect.

Just got a used Jet City JCA22H amp head that is in perfect condition but the tubes were not very good. Someone had installed a real mixed bag of not only brands but types as well. Two of them had gone microphonic. So i ordered 3 of these EHX tubes and holy crap what a difference. They're high gain no doubt which is what a 22H needs (it's a Soldano desgn) but these are really musical throughout and are never shrill or fizzy. They tightened up the bottom end a little and gave the mids a little push too. I used a vintage USA made Sylvania 12AT7 for the PI and a Tung-sol 5751 for the effects loop and this amp really came to life. I couldn't be more pleased. I'm going to order a duet of their EL84 power tubes next to see if they're as good.

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 and It may be great in other tube combination . 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 electroinic under my feet if I don't need it.

Installed 5 of these in my Peavey 6506+ 112 combo and it transformed the amp. The amp has a much more full tone. The clean channel sounds mean and will break up well when asked to and the distortion channel is what it should have been for a high gain metal amp. I was not totally satisfied with the amp before these tubes and was seriously considering selling it. I had replaced the 12" with a vintage 30, had changed the power tubes to JJ, and had played with different pedals. Just could not get the tone I was looking for. What it needed all along was to replace all 5 preamp tubes with these. Now the amp sounds exactly the way I want it to. Very happy with my purchase of these tubes.

First off Electro Harmonix has successfully reproduced vacuum tubes successfully. The 12ax7 is no exception. Somewhere between stocking and Amazon shipping leaves a lot to be desired. This GLASS tube was shipped in a standard Amazon delivery envelope. This is a sensitive glass vacuum device it needs specific packaging.

Replaced the stock unbranded v1 in my Jet City JCA20h with this tube. I can instantly hear a relaxation in the treble that gets rid of that cardboardy upper range of the stock tubes. The whole sound is a bit warmer, smoother, and with more gain. I had to back the bass off a bit and pump the trebly slightly to compensate, but overall, great improvement! Amazon didn't pack the box all that well though :( The tiny tube box was sitting at the bottom of the box with a big wad of the brown paper on top. Solid protection from one side, but completely open to impact on the bottom. I'm glad the tube survived shipment with no microphonics, but it made me worry the moment I opened the box.

Arrived in perfect condition. Works great.

Diese EH-Vorstufenröhre ist eine lohnenswerte Alternative zu der China-Röhre aus meinem Fender Champion 600. Die EH-Röhre bringt keine Nebengeräusche mit sich (wie d. China-Röhre auch), dafür aber dieses schöne Fender-Tweed-Knurren bei höher Lautstärke. Allerdings ist jetzt der kleine 6"-Speaker damit überfordert... ;-) , die EH-Röhre ließ sich leicht in den Röhrensockel stecken, Feb. '26

Funziona bene

Fantastic tubes! I put 2 of these in my valve eq what a difference. They sound amazing. Mids & Tops sound lovely. Yes i defo would recomend these tubes for amps or valve eq's.

livraison rapide et conforme. Très bien.

Replaced an OEM tube with this EH 12AX7 and have been happy with the tone and distortion from my Mesa because of it.