Sovtek 12AX7LPS ECC83 Long Plate Preamp Tube

Sovtek has built a long-standing reputation in the valve world for tubes that deliver serious tone without the premium price tag, and the 12AX7LPS ECC83 long plate preamp tube is a great example of that value. It's a Russian-made 9-pin miniature preamp tube with a high amplification factor, and it's earned a loyal following among guitarists and audio enthusiasts alike.

Sovtek 12AX7LPS — What Makes It Different

The 12AX7LPS is a long-plate, high-mu dual triode with excellent linearity, making it a strong all-round 12AX7 replacement. Its long anode plates and spiral heating design help reduce sensitivity to AC heating interference, keeping the tube quieter in operation.

Tonally, it's full-bodied and well balanced with high gain and a very smooth presentation. Under overdrive, it delivers a slightly less defined edge than some other 12AX7 variants but offers more crunchy fizz, giving it a distinctive character that some players specifically seek out.
Best suited to: Audio and high-end Hi-Fi amps, "modern" Fender-style amps that run more overdrive, and it's also historically favoured as an input tube in vintage Marshall JCM800s.

Fitment note: Like other long-plate 12AX7 variants, the extended plate structure trades some vibration resistance for a warmer, richer tone — long-plate tubes are generally more sensitive to microphonics than short-plate designs, so they're a better fit for stable amp chassis than amps that see heavy knocking around.

Specifications

• Type: 12AX7 / ECC83, long plate construction
• Amplification Factor: 100 (rated), ~94 (measured)
• Plate Voltage (Ua): 330V
• Plate Current (Ia): 8mA
• Plate Dissipation (Wa): 1.2W
• Transconductance: 1.7 mA/V
• Heater Voltage: 6.0–6.6V / 12.0–13.2V
• RoHS compliant
• Sold in retail quantities only

Not sure which valve suits your amp's V1 position? See our guide: Selecting the Right Tube for the V1 Position

For more on how preamp tubes differ from one another, read: What's the Difference in 12AX7 Tubes?

Browse the full range: 12AX7 / ECC83 Preamp Tubes

Given we often recommend JJ & EH 12ax7's we thought a comparison may help when considering the Sovtek 12AX7LPS.

Sovtek 12AX7LPS vs JJ 12AX7 vs Electro-Harmonix 12AX7: What's the Difference?

All three are high-gain 12AX7/ECC83-spec tubes that drop straight into any standard 12AX7 socket, but each has its own personality. The Sovtek 12AX7LPS is a long-plate design offering a full-bodied, smooth, well-balanced tone with a distinctive crunchy fizz under overdrive. The JJ 12AX7 tends toward a warmer, more balanced character with rich harmonics — a safe, versatile all-rounder that suits most applications straight out of the box. The Electro-Harmonix 12AX7 takes the opposite construction approach — a short-plate design — giving it a brighter, more direct, articulate character with an exceptionally low noise floor and more bite under overdrive. If you want a warm, rounded foundation tone, the JJ is the easiest starting point; if you want extra low-end body with a bit more grit, the Sovtek 12AX7LPS is worth trying; and if you want top-end clarity and low noise in a phase inverter or driver stage, the Electro-Harmonix is the better fit.