Best Electro-Harmonix in 2026

Ultra low noise thanks to unique spiral filament which eliminates cathode-to-filament induced hum (common on amplifiers that use AC on the filaments)

Best all-around choice & best value

Single tube

Beam power tetrode with a specially developed cathode coating, careful alignment of the grid, tri-alloy plate material for flawless performance up to 475 volts.

Perfect for high plate voltage amplifiers like the Fender Deluxe Reverb.

Manufactured In Russia

Matched Pair

Matched for both gain and conductance

Spiraled filament allowing for reduced noise

Height: 2.75” (without pins)*

Diameter: 0.87” *

Tube measurements are as follows:

High frequency twin triode preamplifier tube used in studio and hi-fi equipment.

Originally designed for use in audio preamplifiers requiring low microphonics and good linearity, such as Fender "Tweed" Series

Perfect replacement for any 6072/12AY7 type

Superior medium-mu small signal twin triode with high transconductance

Best 12AT7 choice for HiFi

Also suitable for guitar amp circuits

Single tube

Electro-Harmonix is rocking the vacuum tube community with the superior quality of the "EH" series tubes.

Provides high gain with ultra low noise and detailed

Musical tone that rivals the most desirable NOS types

Unique spiral filament

Great tube for guitar and Hi-Fi amps

Tubes are handpicked from balanced inventory

Triodes are balanced within 3% for both gain and transconductance

Exact duplicate of the famous RCA 5U4GB Black Plate

Great quality and sound at a bargain price.

Perfect for all vintage and modern amps

Perfect for high plate voltage amps like the Fender Deluxe Reverb

Mica spacers with metal springs eliminate tube rattle and microphonic

Superior tone and performance to most other 6L6 or KT66 types

Platinum pair (2 tubes), computer-matched by manufacturer on proprietary equipment

High frequency twin triode preamplifier tube used in studio and hi-fi equipment

Tubes are handpicked from balanced inventory

Triodes are balanced within 5% for both gain and transconductance

Matched pair (2 tubes)

Matched within 5% for both gain and transconductance

Direct replacement for any EL34

Extra-low microphonics makes it the best 12AT7 choice for reverb circuits. Also suitable for HiFi.

Factory selected for closest tolerances and most consistent performance

ECC81 equivalent

Straight bottle classic design fits more applications, perfect for dual rectifier amps.

Excellent choice for both Hifi and instrument amplification.

Single tube

Low microphonics, high linearity

Reproduction of the NOS GE 6189

ECC82 equivalent

Electro-Harmonix KT88 Vacuum Tube High power kinkless-tetrode for use in amplifiers such as the Marshall Major

This tube is a favorite of audiophiles

Can be used in place of 6550 for a more "round" bass signature.

Features specially developed cathode coating, careful alignment of the grid, and tri-alloy plate material

Perfect for high plate voltage amps like the Fender Deluxe Reverb

Platinum pair (2 tubes), computer-matched by manufacturer on proprietary equipment

EL34 Matched Power Tubes Hard Duet

The Electro-Harmonix EL34EH is an extremely musical and predictable power tube with a sound that is rich, smooth, and detailed without being edgy

It is the perfect EL34 for vintage equipment and a sure way to improve the performance of modern equipment

Increased thickness of glass envelope for lowest microphonic.

Based on NOS GE Grey Plate 12BH7

Single tube

Electro-Harmonix KT90 power tube

Made in Russia

Absolutely the best KT90 ever developed

Straight bottle classic design fits more applications

Perfect for dual rectifier amps

Excellent choice for both Hifi and instrument amplification

Modulates your axes sound like an envelope filter, but its controlled by an internal oscillator, not your playing dynamics

Analog low pass filter with adjustable resonance; 3 modulation waveform shapes; Tap tempo with tap divide;

Range, Rate and Filter can be controlled from an expression pedal (sold separately)