Electro-Harmonix has introduced a low-noise, low-microphonic version of the 12AX7, meeting all the necessary specifications to be classified as 7025. The original 7025 was a specially tested and selected 12AX7, chosen for its minimal noise and microphonics, ideal for the sensitive first preamp stages of amplifiers. To consistently achieve the 7025 standards, Electro-Harmonix redesigned the 12AX7 structure and adopted new construction techniques to minimize noise and microphonics. Tests on all samples showed undetectable levels of noise and microphonics.

The Electro-Harmonix 7025EH delivers a clear and defined mid-range and a smooth top end, ensuring warmth and balance. These features, combined with its exceptionally low noise and microphonics, make the Electro-Harmonix 7025EH suitable for both vintage and modern high-gain guitar amplifiers, as well as sensitive phono preamps.