RCA 12AX7 - long black plates, phono grade

Testing

This tube tests as new. It has been screened for gas, heater-cathode leakage, shorts, and excessive noise and microphonics on each triode section. It was tested at typical operating voltages on a laboratory grade Amplitrex AT1000 (manual setting, fixed bias mode). Learn more about our testing process here.

Noise and microphonics

Tubes that test as “phono / V1 grade” are the quietest range for noise and microphonics on our custom noise testing equipment. It is an excellent choice for sensitive applications such as V1 positions, microphone preamps, DA converters, and phono stages.

Pricing

This tube is sold individually. It ships in its original box with test results for current draw (mA) and transconductance (Gm) for each triode section.