Miniature high-mu twin triode each section of which has an individual cathode connection - especially suited for use in resistance-coupled voltage amplifiers, phase inverters, multivibrators, and industrial-control circuits.

Russian-made Mullard Reissue 12AX7 dual triode. Large sound stage with excellent detail. Factory selected for low noise and microphonics. Great for hi-fi amps.

9 pin miniature preamp tube (Amplification Factor =100). Very good gain, tight deep bass, fat mids and silky top end with overall definition and brightness. Selected with balanced systems and recommended for guitar amps to improve overall response.

Peavey 'Super 7' 12AX7

9 pin miniature preamp tube (Amplification Factor = 100). The Chinese 12AX7B is very similar in tone to its standard Chinese cousin, but the Bs seem to average in at slightly lower gain and noise.

This Russian tube is full bodied and bright with a more straightforward presentation. It packs a lot of bite with its higher-than-normal gain. In overdrive, it offers a lot of crunchy fizz. High gain preamplifier tube with ultra low noise and detailed, musical tone. Unique spiral filament eliminates filament to cathode induced hum common on amplifiers that use AC on the filaments.

9 pin miniature preamp tube (Amplification Factor = 100). This Russian tube is full bodied and well balanced. It has a high gain with a very smooth presentation. In overdrive, it is not quite as defined as the 12AX7-S-JJ, but it offers more crunchy fizz.

9 pin miniature preamp tube (Amplification Factor = 100). This Russian tube has strong lows and bright highs. Its lows demand attention when playing full bar chords. In overdrive, it offers a lot of crunchy fizz.

Sovtek 12AX7WB dual triode.

Miniature high-mu twin triode each section of which as an individual cathode connection suited for use in resistance-coupled voltage amplifiers, phase inverters, multivibrators, andindustrial-control circuits where high voltage gain is desired.

Sovtek 5751 dual triode.

Miniature, high-mu, twin triode primarily designed for use in low-level stages of high-gain audio-frequency amplifiers. Use of the 7025 in this application is advantageous because of its low hum output.

The TAD 7025 WA delivers full gain with smooth top end. No microphonic issues even with the most sensitive preamps. The 7025 WA supports a fat midrange and creates a bold tone with lots of overtones. Played clean the TAD 7025 WA delivers a warm liquid tone which is very responsive to dynamic playing. Overdriven the 7025 WA provides lots of sustain with well defined mid-range punch.

A dual triode that can be used in place of most 12AX7 circuits. The rugged build of this tube and reduced gain (30% less than a 12AX7) can improve headroom and give better control in high gain stages allowing users to more easily dial in sweet spots. The JJ 5751 features a smooth and balanced tone and a detailed response with low noise and low microphonics.

A new take on the classic 12AX7 preamp tube. While it uses the same rugged build and thick glass as other JJ preamp tubes, this tube differs in construction from the typical 12AX7 in that it features a medium-long plate, which provides a dynamic and open sound with a rich forward sounding mid range. This tube offers low noise and low microphonics.

Sovtek 12AX7WC dual triode preamp tube. Made in Russia.

Tung Sol 5751 dual triode preamp tube. Made in Russia. NOS specs call the 5751 a “special 12AX7” having a high-mu amplification factor of 70.

Low-noise Tube for Best Clean Tone! The TAD Selected 5751 is Tube Amp Doctor's first choice for noticeably improved clarity, smoothness, and a true vintage tone character for most guitar amps!

Warm, clean tone with creamy overdrive! PREMIUM selected quality for the most demanding amp stages. This tube works greatly for warm clean tones and creamy overdrive. We recommend this tube for the 1st gain stage and as input tube. It upgrades 12AX7A and ECC83 tubes and replaces E83CC tubes. The HIGHGRADE Selection is the tip-of-the-top quality at the lowest noise (microphony, hum, hiss) level. Typically only 0.5-2% out of the whole production of this tube meet the HIGHGRADE requirements.

The vintage made in England Mullard ECC83 has been accurately recreated in the Tube Amp Doctor 7025 S. This highly sought after tube is regarded by many as the best dual triode to have ever been created for audio use. TAD offers a reliable and affordable way to experience the sound of this legendary tube.

The 7025 S is notable for its rich and complex harmonics. The warmth in the midrange of this tube stands out among similar preamp tubes. The TAD 7025 has nice round clean tones as well as a creamy yet articulate overdrive. Its rugged mechanical construction with extra thick mica spacers along with TAD’s premium selection process ensures a highly reliable preamp tube. Tube Amp Doctor especially recommends the 7025 S for use in British and British style amplifiers.

The Tube Amp Doctor 7025 works in any 7025, 12AX7, or ECC83 position.

Russian made reissue of the original Tungsol. The Ultimate 12AX7. Big, warm, and musical. High Gain, ultra-low microphonics, and superb linearity with a dynamic 3-D sound. Available with gold pins.

Russian made reissue of the original Tungsol. The Ultimate 12AX7. Big, warm, and musical. High Gain, ultra-low microphonics, and superb linearity with a dynamic 3-D sound. Available with gold pins.

The JJ Electronic 12AX7 / ECC83 has quickly become a modern classic in preamp tubes. Its rugged design and rich harmonics make this tube an obvious choice for musicians who need a reliable and high quality tube at a reasonable price. The balanced tone of the JJ 12AX7 works well in any amp.

The JJ Electronic 12AX7 / ECC83 has quickly become a modern classic in preamp tubes. Its rugged design and rich harmonics make this tube an obvious choice for musicians who need a reliable and high quality tube at a reasonable price. The balanced tone of the JJ 12AX7 works well in any amp.

A high performance, long plate version of the ECC83 / 12AX7. Like all JJ preamp tubes, these are built into a rugged package using the spiral filament and robust plate structure resulting in low microphonics and high reliability. The long plate version of this tube differs from the standard version with its stronger and fuller sound. This tube will work in any 12AX7 or ECC83 position.

A high performance, long plate version of the ECC83 / 12AX7. Like all JJ preamp tubes, these are built into a rugged package using the spiral filament and robust plate structure resulting in low microphonics and high reliability. The long plate version of this tube differs from the standard version with its stronger and fuller sound. This tube will work in any 12AX7 or ECC83 position.

Genalex Gold Lion ECC83/B759 (12AX7) dual triode preamp tube with gold pins. Made in Russia. Original Genalex Gold Lion ECC83/B759 tubes are considered among the best 12AX7 types ever made. They are hard to find and when they are available, they are expensive. They exhibit a large detailed soundstage that is sought after by discerning audiophiles who demand the highest quality sound. The reissue Genalex Gold Lion ECC83/B759 recreates the sound signature of the original. This tube features balanced sections and gold plated pins.

Genalex Gold Lion ECC83/B759 (12AX7) dual triode preamp tube with gold pins. Made in Russia. Original Genalex Gold Lion ECC83/B759 tubes are considered among the best 12AX7 types ever made. They are hard to find and when they are available, they are expensive. They exhibit a large detailed soundstage that is sought after by discerning audiophiles who demand the highest quality sound. The reissue Genalex Gold Lion ECC83/B759 recreates the sound signature of the original. This tube features balanced sections and gold plated pins.