AwTAC Channel Compressor Module Specifications:
Input Voltage Range: +/-15 to 18VDC
Power Consumption: +/-40mA
Size: 5.24″ x 1.49″ x 6.06″
Weight: >1lb
Card Edge Connector
Pin 1 = Chassis (Earth)
Pin 2 = Output +
Pin 3 = N/A
Pin 4 = Output –
Pin 5 = Signal Common (Ground)
Pin 6 = DC Link
Pin 7 = Fader Loop Return
Pin 8 = Input –
Pin 9 = Fader Loop Send
Pin 10 = Input +
Pin 11 = N/A
Pin 12 = +VDC
Pin 13 = Signal Common (0VDC)
Pin 14 = -VDC
Pin 15 = N/A
Drive Control
Unity gain (0 dB) at center (12 o’clock), with +7.8 dB fully clockwise and -9.6 dB fully counterclockwise, continuously variable
High Pass Filter (HPF) Control
Two-position toggle switch applies a first-order filter (6dB/octave) at approximately 375 Hz to the side chain signal when engaged (up)
Reduction Control
Level of signal sent to side chain, continuously variable from -infinity fully counterclockwise to unity gain fully clockwise
Compression Characteristic
Fixed attenuation followed by JFET-controlled variable amplification. Feedback design, peak-detecting, soft knee.
Compression Threshold
Varies according to position of DRIVE and REDUCTION controls. An incoming signal of approximately -24 dBu @ 1kHz is required for compression to begin (defined as -0.5 dB of gain reduction) when these controls are set to their fully clockwise (maximum) positions.
Compression Ratio
Varies from 1:1 to 20:1 according to signal level and threshold (soft knee). Nominally 10:1 when INPUT and REDUCTION controls set to their fully clockwise (maximum) positions.
Attack Control
Three-position toggle switch sets the side chain attack time
1.5mS (Fast) up
40mS (Slow) middle
15mS (Medium) down
Release Control
Release time continuously variable from 75mS fully counterclockwise to 3.4 Seconds fully clockwise
Auto Control
Two-position toggle switch defeats the release control and applies a program dependent release circuit when engaged (up)
Blend Control
Level of uncompressed signal continuously variable from -infinity fully counterclockwise to +9.3 dB fully clockwise, with unity gain (0 dB) at 1:30
Output Control
Level of compressed signal continuously variable from -infinity fully counterclockwise to +17.2 dB fully clockwise, with unity gain (0 dB) at 10:30
Bypass Control
Two-position toggle switch controls relay true bypass circuit, which selects between processed outgoing signal (up) and unprocessed incoming signal (down). Reverts to bypass (unprocessed) position when unit is powered off.
Gain Reduction Metering
Peak-detecting LED indication from -0.5 to -15 dB, in eight carefully selected steps. Displays real-time side chain voltage, regardless of bypass status.
Line Input
Nominally 10,000 Ω balanced bridging, transformer isolated
+4 dBu operating level
Line Output
Nominally 90 Ω balanced, transformer isolated
Max load 300 Ω or greater
+4 dBu operating level
Total Gain
• +27 dB if DRIVE and OUTPUT controls both set fully clockwise, with REDUCTION and BLEND both set fully counterclockwise
Frequency Response (dBu) (Compressed Output)
+0/-1 35Hz to 12kHz
-6 @ 33.66kHz
-3 @ 23.18kHz
-3 @ 16 Hz
-6 @ 9 Hz
Frequency Response (dBu) (Blend Output)
+1/-1 10Hz to 20kHz
-6 @ 52kHz
-3 @ 44kHz
-0.3 @ 10Hz
Phase Shift (Compressed Output)
+102˚ @ 20kHz
+3˚ @ 1kHz
-45˚ @ 20Hz
Phase Shift (Blend Output)
+41˚ @ 20kHz
+1˚ @ 1kHz
-5˚ @ 20Hz
Distortion (THD+N at 0dBu unity gain through, Compressed Output)
No greater than 0.3% 20Hz to 20kHz
0.57% @ 80k
0.04% @ 31k5
0.13% @ 20k
0.55% @ 10k
0.03% @ 1k
0.06% @ 100Hz
0.3% @ 20Hz
0.48% @ 10Hz
Distortion (THD+N at 0dBu unity gain through, Blend Output)
No greater than 0.3% 20Hz to 20kHz
0.12% @ 80k
0.04% @ 31k5
0.03% @ 20k
0.03% @ 10k
0.03% @ 1k
0.08% @ 100Hz
0.26% @ 20Hz
0.52% @ 10Hz
Max Output for 1% THD+N @ 1kHz
Nominally +18 dBu (depending power supply voltages)
Max Input for 1% THD+N @ 1kHz
Greater than +30 dBu (if controls turned counterclockwise, or gain reduction active, to sufficiently prevent max output condition)
Noise (Compressed Output)
RMS 22 Hz to 22khz Unweighted = -78 dBu
RMS 400Hz to IEC-A Weighted = -79 dBu
Selectively Filtered (dBu) = -85 max @ 20kHz to -114 min @ 20Hz, with -95 nominal in the mid band (circa 1kHz)
Noise (Blend Output)
RMS 22 Hz to 22khz Unweighted = -90 dBu
RMS 400Hz to IEC-A Weighted = -93 dBu
Selectively Filtered (dBu) = -96 max @ 20kHz to -122 min @ 20Hz, with -109 nominal in the mid band (circa 1kHz)
Measurements taken from a randomly selected Channel Compressor module, installed in a Purple Audio Sweet Ten rack, using an Audio Precision Portable One Plus (GEN: 40Ω balanced floating, LOAD 20kΩ). Unless otherwise noted compressor signal path engaged, INPUT and OUTPUT controls set for unity gain, with all other controls at full counterclockwise, off, or resting positions. Specifications are subject to change without notice.