Triad's A-9J Input Transformer provides the durability and precision required in today's demanding designs. Mu-Metal case construction for magnetic field immunity and 60 to 80 dB Hum reduction. Large step-up turns ratio to couple low-level input signals to the grid of the first amplifier tube or, in a multistage system, to the input element of the first transistor amplifier. Low level High Fidelity with excellent Unwanted Noise reduction. Applications include signal pre-amplification, inter-stage isolation, signal level step up/down, and impedance matching.