Key Features

Professional ultra clean mic preamp with line level & Hi Z instrument input switches
‘Variable Harmonic Drive’ circuit; a Time Machine of distortion characteristics
High Pass Filter with selectable 40Hz, 80Hz or 120Hz cutoff frequency
Built in professional quality Analogue to Digital conversion - as standard
Auto sample rate sensing and self adjustment
Three band SSL parametric EQ with mid freq Q control and dual LF curves
Intelligent auto compression that maximises recording headroom and avoids DAC clipping

Specifications

Physical *
Depth 230mm / 9" casing only
Height 44.5mm / 1.75" (1 RU)
Width 438mm / 17.25" casing only
482mm / 19" inc’ rack ears
Weight 3.0kg / 7 pounds
Power < 20 Watts
Boxed size 320mm x 550mm x 80mm
12.75" x 21.75" x 3.25"
Boxed weight 3.5kg / 8 pounds

* All values are approximate
Connections
Power IEC320 3-pin connector, 100 – 240 Vac, 50 – 60 Hz
Analogue I/O
Microphone Balanced, 3-pin XLR-F, Zin = 1kO (10kO for Hi Z)
Instrument Un-balanced, ¼" Mono Jack, Zin = 1MO
Output Balanced, ¼" Stereo Jack, Zo = 40O
Insert Send Balanced, ¼" Stereo Jack, Zo = 40O
Insert Return Balanced, ¼" Stereo Jack, Zin = 10kO
Link (2 of) RCA phono, limiter sidechain control voltage (dc.)
Digital I/O
SPDIF In RCA phono, 1V pk-pk, Zin = 75O, SPDIF format.
The ADC will lock to this signal if present.
SPDIF Out RCA phono, 1V pk-pk, Zo = 75O, SPDIF 24bit format.
Synchronised to SPDIF In, else free-runs at 44.1kHz.
Measured Performance
Mic Gain To Output: 20dB min, 76 dB max
Instrument Gain To Output: 26dB min, 82 dB max
Pad Attenuation: 20 dB
Input Impedance (O):
Mic: 1K / 10K
Instrument: 1 MEG
Noise Figure
Equivalent Ein:
Mic, Zin = 10R -130.5 dBU
Mic, Zin =150R -127.5 dBU
Dynamic Range:
Mic Gain Min: 105 dB unweighted
Mic Gain Max: 76 dB unweighted
Common Mode Rejection: 70 dB from 50Hz to 10KHz
with 1Vp-p Common Mode
Max Common Mode In: 5V p-p
Frequency Response
Mic To Out: +/- 0.2 dB from 10Hz to 70KHz
-3dB (LF) : 6 Hz
-3dB (HF) : 250 KHz
Mic Amp Distortion - A Typical Specification
Output Level THD Knob CCW THD Knob CW
+5 dBU 0.03 % 0.1 %
+10 dBU 0.05 % 0.3 %
+15 dBU 0.06 % 0.5 %
+20 dBU 0.09 % 2 %
+24 dBU 0.15 % 5 %
Maximum Analog Output: +24.3 dBU (10K)
EQ
LF Section:
LF Shelf Gain Range: +/- 19 dB
LF Bell Gain Range: +/- 15 dB
Shelf Freq Range: 40 - 600 Hz
Bell Freq Range: 35 - 500 Hz
Bell Q: 1.4
Mid Section:
Gain Range: +/- 17 dB
Freq Range: 300 - 5200 Hz
Q Range: 0.7 - 1.9
HF Section:
Shelf Gain Range: +/- 19 dB
Shelf Freq Range: 1.5KHz - 22 KHz
EQ Dynamic Range: 100 dBU
Limiter
Limiter Threshold: - 3 dBFS
Limiter Ratio: 6, over-easy
Limiter Headroom: 12 dB min, 14 dB typ
Attack Time: 50 uSec
Release Time: 200 mSec
Limiting Distortion: 0.5 % max
Non-Limiting Distortion: 0.001 %

Insert Point
Operating Level
Limiter Switch Out: 24 dBU, unity gain to output
Limiter Switch In: 12 dBU, +12 dB gain to output
Output Impedance (SEND): 150 O
Input Impedance (RETURN): 10 KO
ADC
ADC Type: 24 bit, 192 KHz CS5361 ADC
Sampling Rate: locks to user supplied SPDIF IN
Range: 32 KHz to 108 KHz
No SPDIF In: Defaults to 44.100 KHz
SPDIF In: 200 mV p-p IN min
5V p-p IN max
SPDIF Out (Level): 1V p-p
(Impedance): 60 O

ADC Performance Measured From Insert Return:
Dynamic Range, 20KHz measurement bandwidth
Fs= 32K: 110.5 dB, A-wgt
Fs= 48K: 110 dB, A-wgt
Fs= 96K: 109 dB, A-wgt
ADC Distortion, 1KHz test tone
Level Distortion in 20K meas bw
-0.5 dBFS 0.0006 %
-10 dBFS 0.0015 %
-20 dBFS 0.004 %
-30 dBFS 0.013 %
-40 dBFS 0.04 %
ADC Freq Response
Fs = 48 K: +/- 0.1 dB, 20Hz - 20KHz
Fs = 96 K: +/- 0.1 dB, 20Hz - 40KHz

Miscellaneous
Phantom Power: 47.5V typical
Output Gain Range: +/- 19.5 dB