Duo play:
The following method may be employed for foreign language studies:

First transfer the source material (e.g. disc) onto one track of the tape. When replaying that recording and listening to it via head phones, ones own pronunciation may be recorded on the other track. During subsequent replays both recordings may be listened to, either simultaneously (so-called duo play) or selectively, for the purpose of comparison.

Activated functions:
Playback of channel I (disc recording)

Recording on channel II

Turn stereo/mono mode selector (12) to position I.

Open monitor volume control (11)

Turn monitor selector (14) to position NAB (or TAPE) and listen to channel I via headphones.

Connect microphone to input MIC CH II.

Turn input selector (18) to position MIC LO (or HI respectively).

Press record pre-selector button REC CH II (35) to record on the right channel (button I (32) must be released).

Open potentiometer LEVEL II (17)

VU-meter II (34) will indicate the recording level of ones own voice.

When playing back both recordings switch alternately with stereo/mono selector (12) between I (teacher’s voice) and 11 ones own voice). For listening to both tracks simultaneously (left headphone: teacher’s voice, right headphone, ones own voice) the mode selector switch (12) must be set to stereo. (Note that the second recording will be delayed as a result of the recording to playback head displacement).

Simultaneous recording:
For training purposes in simultaneous translation work one can record the original language on track I while recording the translation on track II at the same time.

Activated functions:
Recording on channel I (32) depressed. Monitoring INPUT channel I (14)

Recording on right channel II (35) depressed.

Connect original language programme source (e.g. tuner, disc etc.) to AUX CH I or RADIO.

Input selector CH I (16) switched to AUX (or RA respectively).

Potentiometer LEVEL I (15) controls level of programme source.

Turn stereo/mono mode selector (12) to position I.

The original language may be monitored during recording via headphones without any time delay. (you can press button SPEAKERS OFF to disable loudspeaker).

To record the translator’s voice connect a microphone to MIC CH II.

Turn input selector CH II (18) to position MIC LO (or HI respectively).

Potentiometer LEVEL II (17) is used to control the recording level of the translation.

Press record pre-selector button REC CH I (32) and REC CH II (35) (same as when making stereo recordings).

The VU-meter I (33) indicates the level of the original language recording whereas the VU-meter II (34) indicates the level of the translation.

For listening to the recording off tape, turn monitor selector (14) to position NAB.

During playback, the two recordings may be compared with one another by switching the mode selector (12) between the positions I and II. In position STEREO both tracks become audible through the respective earpieces of the headphone.

Multi-play recording:
A multi-play recording consists of multiple transfer operations from one track to the other with successive addition of a new voice or musical instrument.

Synchronous playing or singing for each subsequent recording is achieved by listening to the previous recording via headphones (or loudspeakers).

By replaying and transferring the so obtained mix while adding a new voice or instrument 3, 4, 5 or more voices may be combined until the transfer operations will eventually become limited by tape hiss, which increases with each subsequent rerecording.

If a performance takes place in the same room where the recorder is located mixed recording signal must be monitored via , headphones. If separate rooms (control room)  can be used, loudspeaker monitoring is possible.

An example for a typical multi-play recording set-up is given below.

First copy or overdub operation:
Transfer of a recording from track I to track II while superimposing a new signal.

Record first voice or tempo information on channel I (keep the recording level as high as possible).

Connect microphone to MIC CH II.

Turn input selector for channel II (18) to MIC LOW (or HI respectively).

The potentiometer LEVEL II (17) controls the portion of the new signal (second voice) which is to be added.

Turn input selector I (16) to position I > II.

The potentiometer LEVEL I (15) controls the portion of the signal which is being transferred from channel I to channel II.

Press pre-selector button REC CH II (35) (button REC CH I must be released).

The VU-meter II (34) indicates the total of the combined signals from the microphone input and from the transfer operation. Make sure that the modulation is kept as high as possible.

Turn mode selector (12) to STEREO.

Turn monitor selector (14) to position NAB (or TAPE respectively). The position INPUT may be used for rehearsal.

When reproducing the tempo information to the artist via loudspeaker, connect the speaker to the socket LEFT. When using a separate power amplifier connect it to output CH I. If the artist listens to the tempo track via headphones, connect them also to the speaker socket LEFT. The headphones may be connected to the jack PHONES on the front panel as well, however, the right-hand earpiece must then be suitably disabled (turned around etc.).

For rehearsal and monitoring during recording, the right-hand speaker is used. If a separate power amplifier is used, connect it to OUTPUT CH II. When working with headphones, use right earpiece only or connect to speaker socket RIGHT.

VOLUME control (11) adjusts the loudness for tempo playback and monitoring as well.

Use BALANCE control (13) to compensate for any differences in the tempo track and monitoring volume.

Second copy or overdub operation:
Transfer of the first copy from track II to track I while superimposing a new signal.

The mixed signals of the first transfer operation are now on channel II. Since the recording on channel I will get erased in the subsequent transfer operation, the mix on channel I I must be a final one because repetition is not possible, except by starting from the beginning again.

Change microphone connection to input MIC CH I

Turn input selector channel I (16) to position MIC LO (or HI respectively).

Potentiometer LEVEL I (15) controls the intensity of the third voice or instrument which is to be added.

Turn input selector channel II (18) to position II > I.

Potentiometer LEVEL II (17) controls the level of the signal which is to be transferred from channel II to channel I.

Press pre-selector button REC CH I (32) (button REC CH II must be released).

The VU-meter I (33) indicates the total of the combined signals from the microphone plus the track which is being transferred. Make sure to keep modulation as high as possible.

Turn stereo/mono mode selector (12) to position STEREO.

Turn monitor selector (14) to position NAB (or TAPE respectively). Position INPUT may be used for rehearsals.

To replay the previous recording to the artist, connect loudspeaker or headphones to socket SPEAKERS RIGHT. When using a separate power amplifier connect it to OUTPUT CH II.

The headphones may be connected to jack PHONES, however, the left hand earpiece must be suitably disabled.

For rehearsal and monitoring during recording the left-hand speaker is used. If  a separate power amplifier is used connect it to OUTPUT CH I. When using headphones use right earpiece only.

VOLUME control (11) adjusts the loudness for tempo playback and monitoring as well. Use BALANCE control (13) adjust for possible differences in the tempo track and monitoring volume.

Third and subsequent copies or overdubs:
The recording on channel I which now contains the basic melody or voice and two additional voices or instruments may again be transferred to channel II by performing the operations described above.

With high quality tape material and optimum modulation levels up to six transfer operations should be possible.

Echo effects:
Since your A77 recorder is equipped with separate recording and playback heads, echo effects are possible without the use of any additional equipment

Already during recording, the recorded signal is picked-up by the playback head. When returning that signal to the recording head again, it will be recorded on tape once more but delayed by a time interval equal to the distance between the two heads.

The time intervals at which the echo signals repeat themselves vary with tape speed: 1 7/8 ips (special version) 0.70 sec.

3 3/4 ips 0.35 sec.

7 1/2 i ps 0.175 sec.

15 ips (HS) 0.087 sec.

As can be seen from the above, reverberation effects are best achieved at the higher tape speeds, whereas the lower speeds are more suitable for echo effects.

Echo effects during recording:
Connect microphone to input MIC CH II.

Turn input selector channel II (18) to position MIC LOW (or HI respectively).

The potentiometer LEVEL II (17) controls the direct portion of the sound which is to be recorded from the microphone input. This level should be kept as high as possible (while avoiding over modulation in combination with the echo signal).

Turn input selector channel I (16) to position I > II.

Press record pre-selector button REC CH I (32). (Button REC CH II must be in its released position).

The intensity of the echo effect is determined by the position of the potentiometer LEVEL I (15). When opening that potentiometer only slightly, the echo effect will be faint and rapidly decaying. By contrast, if that potentiometer is opened too wide, so that the echo level equals or exceeds the level of the original sound, a feedback howl or whistling will set-in (this may be used intentionally to produce special sound effects).

Turn monitor selector (14) to position NAB (or TAPE).

Turn stereo/mono mode selector (12) to position I.

If the recording has to take place on channel II, the microphone must be connected to input MIC CH I.

Turn input selector for channel II (18) to position II > I.

The functions of the record controls are reversed as well (LEVEL I (15) microphone, LEVEL II (17) echo).

Press record pre-selector button REC CH II (35) (button REC CH I (32) must be in its released position), and turn stereo/mono mode selector (12) to position II.

Adding echo to an existing recording:
The recording to which echo is to be added is already present on track I. The adding of echo takes place while transferring that recording to track II.

Turn input selector channel I (16) to position I > II.

The potentiometer LEVEL I (15) controls the recording level of the sound which is being transferred onto track II. That level should be kept as high as possible (while avoiding over modulation in combination with the echo signal)

Input selector channel II (18) to position II > I.

The potentiometer LEVEL II (17) is used to control the intensity of the echo effect.

Press record pre-selector button REC CH II (35). (Button REC CH I must be in its released position).

Turn monitor selector (14) to position NAB (or TAPE).

Turn stereo/mono mode selector (12) to position II.

When transferring from channel II to channel I the input selectors remain at their above described settings.

The functions of the record controls are reversed.

Potentiometer LEVEL I (15) is used to control the amount of echo whereas potentiometer LEVEL II (17) controls the level of the actual transfer operation.

Record pre-selector button REC CH I (32) depressed (button REC CH II released) and stereo/mono selector (12) turned to position I.

All the above, along with other recording techniques are fully described in the operators manuals of the various tape recorders. These are always available from stock from Brian Reeves