The Vintage Design Pro-Pack is more or less a CA73mk2 and a C1 under the same hood. The signal path is almost the same as in CA73mk2 connected to a C1 minus the C1 output stage. Pro-Pack uses a new input stage which is an updated version of the M81 input stage. The gain switch has 11 positions and a range from 0dB to 50dB gain or 50dB to 80dB with the +30dB switch active. The instrument input uses the same FET circuit as in the DMP and CA73/81. Like the CA73/81 units Pro-Pack also has a separate XLR input, but in the Pro-Pack it's activated by a dedicated switch. New to Pro-Pack is that the HP-filter is now a separate circuit and can be activated without activating the EQ section. A sequence switch for the EQ/compressor is also provided if you like to have the compressor pre-EQ. An all new function is the "AIR" switch which boosts the high frequencies for a more "open" sound. The compressor section is the same as the C1 except for an extra ratio position, 8:1.

Pre Controls:
Front and rear XLR- microphone inputs: the front XLR connector automatically overrides the rear connector when in use
Mic gain range: 0dB to 50dB or 30dB to 80dB with +30dB boost activated
Mic input impedance: 300/1200 ohm switchable from front panel
Line input activated with a switch on the front of the unit
Line gain range: -30dB to +20dB
Line input impedance: 5 kohm
Hi-z: FET instrument input. >1 Mohm. relay switched through the input transformer to get the transformer's character
HP filter: 50Hz, 80Hz, 160Hz and 300Hz
Phantom Power switch

EQ Controls:
LF: Freq 35Hz / 60Hz / 110Hz / 220Hz +/- 16dB
MF: 350Hz, 700Hz / 1kHz / 1.6kHz / 2.4kHz / 3.2kHz / 3.9kHz / 4.8kHz / 7.2kHz / 10kHz +/- 18dB
HF: 8kHz / 10kHz /12kHz / 16kHz +/- 16dB
EQ in/out

Compressor Controls:
Threshold: -20 to +10dB
Ratio: 1.5:1 / 2:1 / 3:1 / 4:1 / 6:1 / 8:1
Attack: 0.5 / 1 / 2 / 3 / 6 / 12 / 25 / 50 mS
Recovery: (release). 25 / 50 / 100 / 400 / 800mS / 1.5S / Auto 1 / Auto 2
HP filter. 50Hz / 100Hz / 7kHz (6dB / octave)
Make-up gain: 0-20dB
Compressor sidechain In/Out (soundpath still active)
Compressor in/out (relay switched true bypass)
Global Controls:
Output fader.
Headroom meter: prefader, calibrated to indicate clip @ +26dB / 600 ohm with level at max.
AIR switch: boosts the high frequencies at 20kHz and extends the frequency range

Phase Reverse
ProPack requires a PSUD for powering.