Used Pioneer JB-100 electret headphone preamp, including Pioneer SE-100 headphones. It is connected between the output stage of the amplifier. Made in 1972.
The earphones are worn.
Matching impedance: 4 to 16 ohms
Rated input: 5V (with SE-100)
Maximum input: 10V (with SE-100)
Output changeover: 0, 6 or 12dB and speaker
Dimensions: 114 x 80 x 217mm
20-35 000 Hz.
Type: electret headphone
Frequency Response: 20Hz to 35kHz
Maximum sound output level: 115dB
Total harmonic disortion: 1%
Cord Length: 250cm