Vacuum Tube - 12AT7 / ECC81, Electro-Harmonix
Superior large plate format Twin Triode, ideal for use in driver and reverb circuits. Offers superior dissipation compared to NOS versions of this tube.
- Excellent 12AT7 choice choice for HiFi
- Also suitable for guitar amp circuits
- ECC81 equivalent
RoHS Compliant
Accessory Items:
| Amplification Factor | 50 | |
| Capacitance, each triode | 1.6 pF | |
| Capacitance, input | 2.5 pF | |
| Capacitance, output | 0.4 pF | |
| Cathode to Heater Voltage | < 200 V | |
| Grid Circuit Resistance (Rg), Automatic Bias, Each Triode | 1.0 MΩ | |
| Grid Circuit Resistance (Rg), Fixed Bias, Each Triode | 0.25 MΩ | |
| Grid Reverse Current | 0.5 μA | |
| Grid Reverse Current Max | 55 mA | |
| Heater Current | 330 - 360 mA | |
| Heater Voltage | 6 V / 12 V | |
| Plate Current (Ia) | < 18 mA | |
| Plate Dissipation, per triode (Wa) | 3.25 W | |
| Plate Voltage (Ua) | < 330 V | |
| Transconductance (S) | 4.5 mA/V |
| Packaging Dimensions | 1 in. × 1 in. × 3 in. | |
| Weight (Packaging) | 0.038 lbs. |
 Specification Sheet | All Models |
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Questions and Answers
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1 answers
Hi there, is this tube the 12AT7EH?
I'm specifically after the 'EH' version.
Regards
Pete
Asked by Anonymous on October 23rd, 2021.
October 25th, 2021
Staff Member
The EH suffix on this tube simply refers to the manufacturer that makes them. Electro Harmonix does not produce a 12AT7 without the "EH" suffix, so they should all be labeled that way.
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
Good ratio price/quality
Refurbished Firestone “Air Chief” AM/FM tube radio circa 1950. AM worked (kinda), but FM was dead. Replaced paper capacitors with Mylar and a couple of burned up carbon resistors. Tested tubes, and many were bad or weak, so I replaced all tubes from TubesAndMore. Now works great.
Good performer and neutral sound. Great for a Hi-Fi amp. I wish tube matching was also offered for small-signal types- it can be important when used as a power amp driver. Like all 12AT7s I have tried, their transconductance is all over the place.
In V3 of my Tweed Blues Jr. Works great and is not microphonic. Would use again.
Great tube. I'm trying it in my Silverface Princeton Reverb for a different sound.
Sweet driver for my '75 Princeton Reverb.
Bought as a spare for my vintage fender amps.