Electro-Harmonix 12AX7

High gain preamplifier tube with a unique spiral filament, top-notch materials and shorter plate structure resulting in supreme microphonic performance. For more clean headroom in your amp, order this tube with the low gain option at no extra cost.(Similar to an NOS 5751 in gain without the price tag). Subject to availability). Avoid these in high voltage cathode follower (CF)spots.

Specifications

 http://shop.ehx.com/catalog/tubes-specs/12AX7EH-SV.pdf