
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 | 0.038 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 |
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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
I put in two of these tubes as the V1 and V2 in my Hot Rod De'Ville 410. These are really just a super simple 12AX7 and when you look at them closely you can tell what I mean. They really do have low noise and microphonics, probably due to their simple design. Everything else about them I can only describe as medium (medium gain, medium tone, medium distortion). For that reason, if you are looking for something that will (probably) work great with any amp or design, these are great. Because it was the first time I was re-tubing my amp, I figured these would be good based on what I had read, and they really are. If you are looking for something that is specifically very high gain or ultra-low microphonics, these might not be for you.
Replaced the generic tube in the V1 of my Stage Right 15 watt. And the difference was great! Distortion was tighter and much more focused,
Bought 4 of these to retube my Peavey VTM 120 and 2 died within 20 minutes of installation. The two I got are great with lots of volume and round off highs and lows but the fail rate is still too high to ever consider getting these again.
First, they didn’t include 5 Ehx 12ax7 in my order.
Second, when they shipped and arrived 2 tubes are faulty.
I’m so happy I found your site. Have had this amp since around 1990, fender champ 12. Nice amp, with the new tube, so much more “complete” sounding. Haven’t changed anything else, yet. Wanted to start here. Cannot wait to actually jam it LOUD, as apartment life keeps it low. But found the tone to be rich and warm.
So far, so good!! Only have a couple of hours play time, but sound great!
i have these in v1 and v3 of my peavey ultra plus and they sound great.. im thinking about getting more to put in my 6505.. i love this tube..