4-in-1 Test/Calibration T1-60 audio cassette tape: L/R, level, speed, azimuth

Azimuth: 10kHz (-10dB ANSI),14 min. Anything with a magnetic field can travel near the tape and disrupt the stability and level of the recording. Left / Right channel check. TDK, Maxell or Sony tapes Type I used (120 μs).

eBay