Vacuum Tube - 12AX7 / ECC83, Electro-Harmonix
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.
Superior high gain short plate format Twin Triode, with ultra-low noise and detailed, musical tone.
- Ultra-low noise thanks to unique spiral filament which eliminates cathode-to-filament induced hum on certain amps
- ECC83/7025 equivalent
For more information about our 12AX7 tubes, see our tech corner article on 12AX7s.
Accessory Items:
Pin Type | Our Part Number | UPC/EAN |
---|---|---|
Regular | T-12AX7EH | 683274020099 |
Gold | T-12AX7-GOLD-EH | 841358101762 |
Amplification Factor | 78 min, 92 nominal | ||
Capacitance, Cathode to Heater | 5.0 nF | ||
Capacitance, Grid to Cathode | 1.6 pF | ||
Capacitance, Grid to Heater | 1.6 pF | ||
Capacitance, Plate to Cathode | 0.44 pF / 0.36 pF | ||
Capacitance, Plate to Heater | 0.44 pF / 0.36 pF | ||
Capacitance, Plate to Plate | 520 pF | ||
Capacitance, grid to plate | 1.6 pF | ||
Grid Circuit Resistance (Rg), Fixed Bias | 1 MΩ | ||
Grid Circuit Resistance (Rg), Self Bias | 2.2 MΩ | ||
Grid Reverse Current | 0.2 μA | ||
Heater Voltage | 6.0 - 6.6 V / 12.0 - 13.2 V | ||
Heater to Cathode Voltage, Negative | 200 V | ||
Heater to Cathode Voltage, Positive | 100 V | ||
Plate Current (Ia) | 9 mA | ||
Plate Dissipation, per triode (Wa) | 1.0 W | ||
Plate Resistance (Ra) | 54.1 kΩ | ||
Plate Voltage (Ua) | 300 V | ||
Transconductance (S) | ≥ 1.4 mA/V, 1.7 mA/V nominal |
Packaging Dimensions | Gold version | T-12AX7-GOLD-EH | 2.75 in. × 1 in. × 1 in. |
Regular version | T-12AX7EH | 1.1 in. × 1.1 in. × 3.1 in. | |
Weight (Packaging) | Gold version | T-12AX7-GOLD-EH | 0.0309 lbs. |
Regular version | T-12AX7EH | 0.0353 lbs. |
T-12AX7-GOLD-EH - Gold version | Amplification Factor | 78 min, 92 nominal |
Capacitance, Cathode to Heater | 5.0 nF | |
Capacitance, Grid to Cathode | 1.6 pF | |
Capacitance, Grid to Heater | 1.6 pF | |
Capacitance, Plate to Cathode | 0.44 pF / 0.36 pF | |
Capacitance, Plate to Heater | 0.44 pF / 0.36 pF | |
Capacitance, Plate to Plate | 520 pF | |
Capacitance, grid to plate | 1.6 pF | |
Grid Circuit Resistance (Rg), Fixed Bias | 1 MΩ | |
Grid Circuit Resistance (Rg), Self Bias | 2.2 MΩ | |
Grid Reverse Current | 0.2 μA | |
Heater Voltage | 6.0 - 6.6 V / 12.0 - 13.2 V | |
Heater to Cathode Voltage, Negative | 200 V | |
Heater to Cathode Voltage, Positive | 100 V | |
Plate Current (Ia) | 9 mA | |
Plate Dissipation, per triode (Wa) | 1.0 W | |
Plate Resistance (Ra) | 54.1 kΩ | |
Plate Voltage (Ua) | 300 V | |
Transconductance (S) | ≥ 1.4 mA/V, 1.7 mA/V nominal | |
T-12AX7EH - Regular version | Amplification Factor | 78 min, 92 nominal |
Capacitance, Cathode to Heater | 5.0 nF | |
Capacitance, Grid to Cathode | 1.6 pF | |
Capacitance, Grid to Heater | 1.6 pF | |
Capacitance, Plate to Cathode | 0.44 pF / 0.36 pF | |
Capacitance, Plate to Heater | 0.44 pF / 0.36 pF | |
Capacitance, Plate to Plate | 520 pF | |
Capacitance, grid to plate | 1.6 pF | |
Grid Circuit Resistance (Rg), Fixed Bias | 1 MΩ | |
Grid Circuit Resistance (Rg), Self Bias | 2.2 MΩ | |
Grid Reverse Current | 0.2 μA | |
Heater Voltage | 6.0 - 6.6 V / 12.0 - 13.2 V | |
Heater to Cathode Voltage, Negative | 200 V | |
Heater to Cathode Voltage, Positive | 100 V | |
Plate Current (Ia) | 9 mA | |
Plate Dissipation, per triode (Wa) | 1.0 W | |
Plate Resistance (Ra) | 54.1 kΩ | |
Plate Voltage (Ua) | 300 V | |
Transconductance (S) | ≥ 1.4 mA/V, 1.7 mA/V nominal |
Specification Sheet | All Models |
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Substitute Products
The following items can be substituted for this product. While not necessarily exactly the same, they will function as replacement items in your project.
Product Reviews
Not at all recommended for use as AC or DC coupled cathode followers or in any inverted cascode circuits. They are just not up to the task at all. Not good for reverb drivers either. They are just not a very robust tube. They are mediocre okay for single inverting gain stages, but also not recommended for any phase inverter duties either. Mid 1980s DC biased Hi Watt PI use will kill these really fast too. That is a quasi cathode follower or as a regulated DC bias supply for a cathodyne PI. Most New Sensor tubes should not be used in any of these circuits.
These are pretty good. When people say "British" in describing them I think they mean the bass is rolled off relative to the other frequencies so you hear a mid frequency emphasis that works well with crunch and leads, or really high gain sounds. I like them earlier on in the gain stage, V2 or in the last stage before the CF and EQ, V4.
Dave Friedman says he selected EH for his amps as reliable, and ship out standard compared to others he tried, which either failed or didn’t sound great. These and EH EL34 narrow bottle are what I found work great in Marshall Plexi 100 watt and give me all the classic British violin smooth tone I crave. Yum!
Just like Dave Friedman said, and why he likes them. British style, old school, EH slim bottle quad EL34 with EH 12AX7 high gain preamp tubes. Gives all that I need from Marshall Plexi 100w. Very violin like, if you dig that, and that’s exactly what I want! Thanks.
EH 12AX7 tubes are a great But what's even better is the customer service I received from tubes and more. With a good client's repair on the bench who is moving in a week I ordered 12AY7s accidentally. Emailed The guys at tubes and More explaining the situation the service was impeccable I received an RA number, the correct order was put in the system and shipped out immediately then the difference as well as the credit was processed in more than a timely manner. As a business owner this kind of customer service really stands out and makes a difference of who I'm going to order from in the future. Tubes and more is at the top of my list and I'm very pleased with The price and of course the service I received.
perfect!
4.5 star
These are great sounding, reasonable tubes!
Excellent service and products!
Used in V1 in my Reeves 225, sounds excellent & can be recommended.