dbx 128 - SPECIFICATIONS; dbx II Tape Noise Reduction Specs

36
SPECIFICATIONS
dbx JI Tape Noise Reduction Section
DYNAMIC RANGE
110dB (unweighted background noise-to-peak signal ratio)
INPUT IMPEDANCE
50k-ohms
OUTPUT IMPEDANCE
MAXIMUM OUTPUT LEVEL
EFFECTIVE NOISE REDUCTION
COMPRESSION/EXPANSION SLOPE
Designed to feed tape recorder inputs 5k-ohms or greater.
7 volts RMS at 1kHz into 5k-ohm load
30dB for tape recorders with a signal-to-noise ratio greater than, or equa! to 45dB
40dB for dbx-encoded discs (A weighted)
2:1 constant linear decibel
TRACKING ACCURACY
+1dB per 20dB for record/playback cycle
LEVEL ADJUSTMENTS
100 millivolts to 3 volts for unity gain; for convenience in level setting and avoidance of
overload in succeeding audio stages; level setting unimportant for record/playback tracking.
FREQUENCY RESPONSE
LEVEL ADJUSTMENT
HARMONIC DISTORTION
+0.5dB, 50Hz to 15kHz
+1dB, 30Hz to 20kHz: single sinewave record/playback cycle
+0.25dB, 30Hz to 20kHz for complex music program
—3dB at 20Hz for tape noise reduction; ~3dB at 27Hz for disc playback mode
100mv to 3V for Unity Gain; for convenience in level setting and avoidance of overload
in succeeding audio stages; level setting unimportant for record/playback tracking.
2nd harmonic distortion less than or equal to 0.1% for record/playback cycle from
30Hz to 15kHz
3rd harmonic distortion less than 0.1% for record/playback cycle from 100Hz to 15kHz
3rd harmonic distortion less than 0.5% for record/playback cycle from 30Hz to 15kHz
IM DISTORTION
0.15% typical; 0.3% maximum (using GOHz and 7kHz at a ratio of 4:1 per SMPTE method)
IMPULSE RESPONSE
Risetime is less than 20 microseconds. Release rate - 240dB/second.
NOTE: All above measurements were made with a 1 volt RMS input and output signal.
Specifications continued on next page.