Sony 1983
Betamax PCM-701ES

digital pcm logo


Front display
Front display and controls

Level controls
Recording level and resolution controls

The PCM-701ES is a digital audio processor which was often paired with an SL-C9. So what is PCM?. It allows for an audio signal to be digitized into CD quality and recorded onto a video cassette. The recorded video being a digital representation of the audio. The recording can then be played back on the same unit.

The build quality of this range of units was exceptionally good. The electronics rarely fail and are often still found in full working order today. They were designed to be paired with Betamax units, although they sometimes also worked with VHS players depending on where the switching point was (enough of the screen was recorded).

When connected to an SL-C9, the PCM switch on the rear of the machine is used to disable the drop-out compensator circuitry. This allows the error correction in the digital signal to perform more efficiently.

Control functions

POWER switch
Press to turn on the power. The peak program meter indicators will illuminate ; to turn the power off press the switch again.
HEADPHONES jack (stereo phone jack)
Insert the headphones to monitor recording input levels, or to listen to a recording in the playback mode.
ATT (headphone attenuation) control
5-step volume adjustment for headphone listening.
COPY (digital tape copy) button
Set this button to ON for digital-to-digital tape copying using a pair of video recorders and the COPY OUT jack at the rear. An indicator illuminates above the button when the copy switching is activated.

Be sure to set the copy button to OFF except for digital tape copy. With the button set to ON, signals are not transmitted through the VIDEO OUT jack

PB MUTING (playback muting) button
The playback muting circuit activates automatically when you turn on the unit, and an indicator lights above the button when the muting circuit is functioning. You only need to press the playback muting button when you want the muting function turned off. The playback muting circuit cuts out sound reproduction when frequent dropouts occur due to mistracking of the heads of the video recorder, or scratches and dust on the magnetic tape. If you do not want the sound reproduction cut off, such as with low quality tapes, set the PB Muting button to OFF.
The PCM-701ES peak program meters feature two types of peak level indications.

When the AUTO button is pressed : successive peaks are held for approximately 1.7 seconds, except when a higher peak occurs before 1.7 seconds have elapsed, in which case the peak is im-mediately indicated. This mode of peak level indication is activated automatically when the power is turned on.

When the MANUAL button is pressed : the peak level will be held on the scale until a higher peak occurs, in which case the latter peak is held. To reset the peak held on the meter, just press the manual button. This method of peak input is useful when you want to know both the highest peak on a tape or disc, or when you want to know both the highest peak as well as intermittent peak input levels for live recording.

METER selector button
Press this button to convert the peak program meters into a tracking meter. Each time the selector is pressed. the function of the meter changes. When the power is turned on initially. the peak pro gram meters function automatically.
REC MUTE (record muting) button and indicator
Keep this button depressed to eliminate unwanted material and to create blank spacing between selections when recording. The REC MUTE indicator illuminates while the button is held depressed and the level of the recorded signal is reduced to zero. While the record muting is operating, the video control signal of the video recorder is still transmitted to permit proper playback.
REC RESOLUTION (record resolution) selectors
These buttons select the resolution for recording.

14-BIT: for recording in accordance with the technical specifications of the Electronic Industries Association of Japan lEIAJI which has adopted the 14-bit linear quantization format. Press this button when the tape recorded with this unit is to be played back using another PCM digital audio processor which conforms to the 14-bit quantization format of the EIAJ.

16-BIT: for recording and playing back in the 16-bit quantization format. As the 16-bit format offers a wider dynamic range and less distortion than the 14-bit format, normally use the 16-BIT selector setting. During playback, the proper quantization format is automatically selected for the tape being played.

REC LEVEL (recording level) controls
These controls adjust the recording level. The outer control is for the left channel, and the inner control is for the right channel.