Pair of NOS General Electric 12SN7GTA Tubes €“ Dual Triode
If you are looking for the impeccable linearity of the 6SN7 family but your equipment supports a 12.6-volt heater supply, the NOS General Electric 12SN7GTA Tubes are the secret choice of audiophiles and sound engineers. Being electrically identical to their 6V counterparts, they deliver the same three-dimensional soundstage, deep bass, and crystal-clear highs, but at a fraction of the market cost.
History and Authenticity (EIA Code 188)
General Electric was one of the undisputed giants of the golden age of vacuum tubes. The markings on these tubes reveal the EIA code €œ188,€ confirming that they were manufactured at the legendary GE plant in Owensboro, Kentucky, famous for its strict military-grade standards and durability. The black-plate design and robust internal structure minimize microphonics, a critical factor in preamplifier stages.
Uses and Applications of the NOS General Electric 12SN7GTA Tube Pair:
Hi-Fi Audio (High Fidelity): Stereo line preamplifiers, phase splitters in push-pull power amplifiers.
DIY Projects: Tube headphone amplifiers (e.g., OTL designs) where the power supply can be adapted to 12V operation.
Vintage Restoration: Antique radios, laboratory test equipment, and classic Hammond organs that use the 12SN7 series.
Detailed Technical Specifications:
Tube Type: Dual triode, mu-follower type (medium-mu dual triode).
Base: Standard Octal (8-pin) socket (8BD).
Heater Voltage: 12.6 V AC/DC.
Heater Current: 0.3 A.
Maximum Plate Voltage: 450 V (GTA version, higher than the standard GT).
Maximum Plate Dissipation: 5.0 W per plate (7.5 W combined for both plates).
Amplification Factor (Mu): ~20.
Typical Transconductance: 2600 µmhos (at 250V plate voltage).
Condition of Sale and Testing:
This item is a New Old Stock (NOS) component. It includes its original General Electric boxes (with expected signs of wear due to decades of storage). Note: For full transparency, we inform that this pair has been tested on a Hickok 800 tube tester, showing excellent results for both tubes.
(FAQ)
Q: What is the difference between a 12SN7GTA and a 6SN7GTA?
A: They are electrically and sonically the exact same tube. The only difference is the heater voltage requirement: the 6SN7 requires 6.3V at 0.6A, while the 12SN7 requires 12.6V at 0.3A.
Q: What does the €œGTA€ designation at the end of the model mean?
A: The €œA€ indicates an upgraded dissipation rating. These tubes support up to 450V on the plate and a total dissipation of 7.5W, making them much more robust and durable than the standard €œGT€ version.
Q: What does €œNOS€ mean and why do you only guarantee the filament?
A: NOS stands for New Old Stock (components manufactured decades ago but never used). We guarantee filament continuity because we do not have a calibrated transconductance tester (such as an Amplitrex) to certify emission values, which is reflected in a more accessible price.
Q: Can I use these vacuum tubes in a guitar amplifier?
A: Generally no, they are not direct replacements, as guitar amplifiers typically use the 12AX7 series 9-pin tubes (high gain). These are octal-based and low gain, designed mainly for Hi-Fi audio equipment and vintage radios.
