Dolby Noise Reduction; Calibration - Revox C115 Operating And Service Instructions

1.5.5 Dolby noise reduction system"
Dolby-B:
The Dolby-B noise reduction system increases the level
of the weak signals in the mid and high frequency range
during the recording process, and correspondingly
deemphasizes these signals during playback. The play-
back corresponds exactly to the original sound, but the
tape noise will be reduced.
Dolby-C:
1.5.6 Calibration
The factory optimizes the cassette deck alignments to
the cassette types specified in the "Technical data".
When the cassette is inserted, the tape type is automati-
cally selected and shown on the display segment [G].
The BIAS and CALIBRATION potentiometers are used
for adjustment to different batches of the same cassette
brand, as well as to different brands of cassettes type |
and fl.
With CALIBRATION the source/tape level can be ad-
justed to identical values based on the level indication [K]
on the display.
With BIAS you can align to identical treble reproduction.
Comparison is possible by changing over between
SOURCE / TAPE in record mode. As a test signal the
noise of an FM tuner (without signal and without muting),
or any other high-frequency audio source can be used.