Electro-Harmonix 7025/12ax7 tube

Electro-Harmonix 7025/12ax7 tube

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Electro-Harmonix 7025/12ax7 tubeLoading...

Electro-Harmonix has released a low noise, low microphonic version of the 12AX7 that meets all specifications required for the tube to be designated 7025. The original 7025 tube was a 12AX7 that was tested and selected for the lowest noise and microphonics for use in the critical first preamp stages of amplifiers where noise and microphonics could be an issue. In order to ensure that the 7025 specification is consistently met, Electro-Harmonix has redesigned the structure of the 12AX7 and has implemented construction techniques to ensure the absolute lowest noise and microphonics possible. In all samples tested, noise and microphonics could not be detected.

The Electro-Harmonix 7025EH has a mid-range that gives clarity and definition to the sound and a smooth top end for warmth and balance. With these characteristics, along with the exceptionally low noise and low microphonics, the Electro-Harmonix 7025EH will work equally well in vintage and modern high-gain guitar amplifiers, as well as sensitive phono preamps.

Electro-Harmonix 7025/12ax7 tube
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4 thoughts on “Electro-Harmonix 7025/12ax7 tube

  1. A new release with a completely new plate structure. Actually the plate structure is exactly the same as their 6922 tubes and similar to Frame Grid tubes from Telefunken and Tesla.

    Call me impressed, but the tube showed -89dB of noise. That’s incredibly good. Usually, 12ax7 tubes are on a noisy side and show around -86db. Great job on that. Also, practically no microphonics! I had to hit a tube hard to get any feedback and even then it was around -84dB, where regular tubes would drop to -70dB.

    Sound-wise, the tubes actually do sound very similar to 6922, very transparent, very dynamic with the great sound stage. Not as involving as Genalex B759, but a great sounding tube.

    There is one downside though, a gain of the tubes is not at 100 as 12ax7 should show, but it’s around 80-90dB, so higher than 5751, but not as high as 12ax7.

  2. One of the key questions for me was how does it stand up to vintage 7025, so I selected Ameperex Buggle Boy 7025 made in Holland. The gain was also 90db, but to my surprise, Ameperex is much noisier and more microphonic – noise -85db, microphonics dropped noise to -70dB, which is good, but not even close to EH 7025. Nice job, Electro-Harmonix.

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