• Ultra-low noise thanks to unique spiral filament which eliminates cathode-to-filament induced hum on certain amps
• Best all-around choice and best value for 12AX7
• ECC83/7025 equivalent
• Many OEMs use relabeled Electro-Harmonix vacuum tubes in their amplifiers

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