What is a 12AX7?
12AX7 tube is a high gain dual triode tube found in many tube amps.
Because of the high gain, the 12AX7 tube is often used in the V1 position of guitar amps, which has a lot of effect on sonics. It is the tube that defines the sound of your amp in a big way.
If you are looking to upgrade the tubes in your amp, 12AX7 in V1 is where you want to start.
Below are our top 12AX7 picks to help you with your selection.
Best 12AX7 For Guitar and Bass Amps
TungSol 12AX7 is our go-to tube for guitar amps.
Tung-Sol 12AX7 is a great all-rounder that delivers good gain without washing out the fine details and textures.
When in doubt, we start with Tung-Sol 12AX7. TungSol 12AX7 handles everything from vintage rock to a clean tone sound.
Mullard 12AX7 is a long plate design which makes it a tad more susceptible to Microphonics, so we recommend a low noise option if you use a high-gain amp.
Want to try them all? Our 12AX7 Sampler Set has all three tubes above.
We carry many more on our 12AX7 Page
Shuguang 12AX7B - The Silver Dragon
UPDATE: Unfortunately, the Shuguang factory closed a while back, and Shuguang 12AX7B tubes are no longer available. We have a very limited stock left.
12AX7B Silver Dragon is the favorite amongst metal musicians, and for a good reason.
If the high gain sound is what you are after, the 12AX7B Silver Dragon tube will do very well.
We take great care in testing and screening these tubes since we know they will be used with the volume wide open. Once we toss all the duds, we refer to the remaining punch-packing12AX7B as the "Silver Dragon."
Best 12AX7 For Audio
Genalex Gold Lion 12AX7
Like all Gold Lion Tubes, Gold Lion ECC83 is built with meticulous quality, which makes it ideal as the premium upgrade for any audio 12AX7 application.
You may have also noticed a Genalex Gold 12AX7/ECC83 Standard Pin version. The standard pin version is a small plate design that is different from the gold pin version.
The standard pin version is a good value, but we think the Genalex Gold Lion ECC83/B749 gold pin is the better of the two.
Mullard 12AX7 is an excellent choice for upgrading the factory-installed 12AX7 and has become the go-to standard for audio applications.
Best Value 12AX7
If you are looking for the most value for the money, it's hard to beat Electro-Harmonix 12AX7EH for guitar amps. Electro-Harmonix 12AX7EH is a workhorse, and is often the original OEM tube shipped in amps.
For audio applications, Sovtek 12AX7LPS provides good resolution and rich low-mids at a good value point.
Some Notes About 12AX7
12AX7 and the gain
Instead, the gain affects the tone and noise floor. The higher gain doesn't always mean a better tone, so we encourage you to try different 12AX7 tubes and see what works for you.
12AX7 and Microphonics
High gain of 12AX7 tube also means there are more chances for microphonic noise.
Microphonic noise is caused by the tube picking up mechanical vibration and amplifying it. This is just like how a microphone works, hence the term "Microphonic."
Some amount of microphony is reasonable for a vacuum tube. What we want to avoid are tubes that are excessively microphonic, resulting in unwanted ringing or feedback.
We screen all our 12AX7 for excessive microphonic noise, but if your gear is sensitive to microphony (phono amps or tube mics), we offer the low-noise screening option.
If you want the absolutely the lowest microphonic, we recommend Electro-Harmonix 7025EH. It is specifically designed to be ultra-low noise.