User guide
True to the Music
Radial Engineering Ltd.
Workhorse User Guide
15
SPECIFICATIONS
Circuit type:  Virtual earth mix buss integrated 
operational amplifi er - Class AB
Max output level:  +22dB (20Hz to 20kHz)
Voltage Gain:  Up to +23dB on the main output 
Distortion:  0.007% @ 1kHz with 10dB in and 10dB 
out
0.05% @ 20Hz with 10dB in and 10dB out
Signal to Noise:  -91dB with +20dB output 
Card Slot Inputs:  8 x balanced XLR, ¼” TRS, D-SUB 
Card Slot Outputs:  8 x balanced XLR, ¼” TRS, D-SUB 
Card Slot Impedance:  Depends on modules used
Internal Mix Buss:  4.75k Ohms input coupling resister
Summing Mixer Input:  DB-25, Unbalanced +4dB/-10dB 
with up to +20dB capacity; 
input impedance = 4.75K Ohms
Main Output:  +4dB balanced stereo XLR and ¼” TRS 
outputs; Jensen™ transformer isolated
Main Inserts:  ¼” TRS - tip = send; ring = return
Monitor Output:  +4dB balanced stereo XLR and ¼” TRS 
outputs; transformerless; +4dB balanced
Headphone Out:  ¼” TRS Stereo - 2.8VRMS @ 8 Ohms 
(up to 7VRMS depending on headphone 
impedance) 
Ground:  Red: audio, Black: chassis
Power Supply Input:  100V - 240V AC (50~60Hz)
Power Supply Output:  1600mA - External switching type with 
5-pin XLR, +/-16 VDC; 48V phantom
Dimensions:  19” wide x 5.25” tall x 7.44” deep 
482.6 wide x 134 tall x 189mm deep
Weight: 22lbs / 10kg
MONO / STEREO SW
D-SUB INPUTS D-SUB OUTPUTS SUMMING MIXER INPUTS
INPUT OUTPUT INPUT OUTPUT
OTHER
INPUTS
4K75
4K75
CHANNEL 8
FEED SW
LINK SW
CARD SLOT 1
OMNIPORT
EXPANSION BUSS
STEREO INPUTS
MIXER CH. 2
LEVEL
MIXER CH. 1
LEVEL
OVERLOAD
LED
MIXER CH. 2
ON/OFF
MIXER CH. 1
ON/OFF
PAN
EXPANSION BUSS
STEREO OUTPUTS
MAINS INSERT
MAINS INSERT
FEED TO
NEXT CHANNEL
INSERT: TIP=SEND / RING=RETURN
MASTER BUSS
PIN 11
MIX BUSS
PIN 11
MIX BUSS
PIN 9
PIN 7
PIN 9
PIN 7
HEADPHONE
OUTPUT 
MAIN OUTPUT
RIGHT
MAIN OUTPUT
LEFT
MONITOR OUTPUT
RIGHT
MONITOR OUTPUT
LEFT
MONITOR
LEVEL
MONITOR
ON/OFF
MASTER 
LEVEL
MASTER 
ON/OFF
OMNIPORT
CARD SLOT 2
PAN
OVERLOAD
LED
HEADPHONE 
LEVEL
TRANSFORMER
ISOLATION
TRANSFORMER
ISOLATION
WORKHORSE BLOCK DIAGRAM










