Batting Practice for the AV Professional
and primer for the novice
5 Page 2
The AV System Sequence
The Record Loop
- Legacy receivers, some AV receivers, plus audiophile
preamps include a useful diverting exit and reentry
It is the tape-monitor output and input record loop.
Think of the input/output loop as an audio off-ramp with a
quick on-ramp. As a selected source begins its path
to the pre-amp output, prior to entering any audio
manipulation or processing, the source
simultaneously exits at the record output.
The source volume at the record output is fixed.
The fixed output can advance to the input of a recording
device. The re-entry record input is still prior to
any manipulating or processing. Engaging a front
panel tape monitor switch allows the recorded audio to
reenter and continue to the preamp output. Engaging
the tape monitor over-rides all other source selection.
But why is the tape
monitor a separate dedicated priority switch?
A point of tape loop confusion derives from the word
monitor of the Tape Monitor switch. Monitor is to
observe or listen.
Audio enthusiasts and the 3rd head
Many tape recorders provided a 3rd-head linked to
a Tape Monitor switch on the
recorder. The 3-head feature allows the
listener to monitor, to listen, to the result of their
recording as it is still recording.
The 3rd playback-only
head is located after the 2nd record-only
head, and the initial 1st
erase/bias head. Engaging the recorder's
Tape Monitor switch allows listening to the 3rd head
playback result of the 2nd record head while
recording. The tape deck includes a headphone
monitor jack for this function.
The 3rd head result can also
pass to a connected receiver/preamp via the tape
deck output jacks to the receiver/preamp tape monitor
input jacks. Therefore, selecting the receiver/preamp Tape
Monitor switch also allows listening to the recorder 3rd
head. This allows comparison between the
selected source and the recording.
Silent and Confused
The tape loop confuses many owners of tape loop
The receiver/preamp tape monitor switch overrides all
If engaged, and a tape player is not connected while
playing, listeners are confronted with silence.
Disengaging the tape monitor allows normally selected
sources to pass.
Miss-engaged tape monitor switches led to many distressed
phone calls to audio stores in the 1970s and 1980s.
- Note: If the loop was
not used, connecting the output to the input with an audio
interconnect avoided angry phone calls.
Record Loop Processing Options
1. The preamp record tape loop can optionally engage an
equalizer, reverb, audio mixer, or surround sound decoder
rather than a tape recorder.
The engaged tape monitor loop passes decoded, equalized,
or reverb processed audio to the preamp output.
2. Many receivers and preamps also included a record-output
selector. This switch offers the option of
routing a source to the record output,
while allowing the main input selection switch to choose a
different source to pass to the preamp output.
3. Many audio dealers used the tape output and
record-output selector to route sources to an
preamp/amplifier in another room or zone.
Multi-room / Multi-source
Many manufacturers have re-labeled the 'record
output' as the 'multi-room
output', and the 'record
output selector' as a 'zone
2 source selector'. This feature promotes
the routing of sources to an amplifier and speakers in
another room or zone. However, they eliminated the
Tape Monitor switch and its dedicated input.
Ed's AV Handbook
Copyright 2007 Txu1-598-288 Revised 2022
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