Electro-Harmonix 12AX7 Preamp Vacuum Tube
From our review of the Electro-Harmonix 12AX7 vacuum tube: "The EH-12AX7 preamp tube has a nice balanced sound, a very low noise floor and excellent performance in terms of microphonics. The lack of microphonics may be due in part to the return of a shorter plate structure or better materials. I've had some samples that were tried in various amp stages. Pre-amps, tone stacks and phase inverters, a winner in every location...I have used the EH to successfully tame amps that defied all other attempts to kill microphonics and unwanted feedback. This tube is a winner, buy 'em and try 'em, they may be just the piece you've been looking for."
One other note about the construction of these Electro Harmonix 12AX7 tubes is they have filaments that are almost completely encased in the plate structure. They often don't "light up" when working properly. This is not a problem, it's normal for the 12AX7-EH.
Other Electro-Harmonix tubes
12AX7 TypesAdditional Information and Downloads
Reviews:
12AX7 Tube Review
Tube Matching Information:
Matched Sections Service
Downloads:
Electro-Harmonix 12AX7-EH Datasheet (PDF)
Download Adobe Acrobat PDF reader
Warranty Information and Return Policy
Warranty Period: 3 monthsAll our tubes are guaranteed for 3 months from the date of purchase. (Any exceptions will be noted on that tube's Warranty tab)
If you receive a tube that does not perform to the manufacturer's specifications, please do the following:
- contact us to get a return authorization
- return it via regular mail within 90 days from when we shipped it, and we will provide an exchange or refund of the full purchase price of the tube.
Returns not related to warranty or defect will be considered at our discretion, and are subject to a 15% restocking fee.
We can not accept returns that don't have an authorization, are past 3 month, or are returned improperly.
These guidelines may be updated without notice.
Ratings & Reviews
19 reviews
Electro-Harmonix 12AX7 | Different than the others
by Ben
EH are the first of Sovtek's premium line of tubes. Tung Sol, Mullard and Svetlana are the others. The others are smoother and warmer. These EH tubes are brighter and sharper, at least to my ear. They still sound great with overdrive. I think they are also a good fit for a Fender amp.
Electro-Harmonix 12AX7 | One of the best values
by Mr. V Amps
I like these EH-2AX7's... they have strong gain and good tone. I find these Electro-Harmonix tubes to have much of the same characteristics of the Tung-Sol, in a more affordable price. I use these in many of my new amp builds.
Electro-Harmonix 12AX7 | Microphonic in 1 month
by steven
I replaced the tubes in my amp with these EH-12AX7 they are what came in it new and had no problem for years now 1 tube has gone microphonic in just a month i hope it was just a bad one time will tell has me wondering if i should have went with a different brand.
Excellent distortion tube
by Precision70
Use it in my old Peavey Classic 30 on drive chanel along with Tung Sol on clean chanel. Sounds sooo much better than JJ on Peavey. Oh and use EH in power section as well.
Not good in cathode folllower
by Andre R.
The sound is pretty good but don’t use them in cathode follower they will create arcing problems with those spiral filaments, otherwise this is a real great tube .
Awesome customer service and fast shipping 👍