Appsys ProAudio: RGC-24A-M

Remote Gain Control for (almost) every preamp!

Digital snake systems like our ADAT Multicore Extender have many advantages. But with these systems, the mic preamps are usually located on stage, and you cannot adjust the gain locally from FOH - this can be an issue if you just wanted to "give some dB less" during the show.

Remote controllable preamps are the solution, but they are hard to find and even more expensive - not the right thing when building a low-budget system. That's why we developed a modkit which works with most preamps and allows you to add remote gain control via MIDI. Simple to do, even simpler to use. 


In remote mode, gain adjustment is entirely done over the optocouplers. They are controlled by an external box (the Remote Gain Controller) which is in turn controlled via MIDI from the mix console at FOH position (the MIDI channel of the ADAT-Multicore-Extender ADX-32B and ADX-64B-PRO can be used for this purpose). When remote control is active, the original gain pots must be in leftmost (min) position. If local control is desired, the Remote Gain Controller can be switched off by either pressing the "MODE" key, by issuing a MIDI message, or by simply removing the control cable from the preamp.  


ART TubeOpto 8  
Behringer ADA8000 
Focusrite OctoPre mkII 
Focusrite OctoPre mkII Dynamics 
Mackie Onyx 800R 
Presonus Digimax D8 
RME Octamic 
all other preamps where the gain pot is between 5k and 50k (log taper) and is used in 2-pin (rheostat) configuration. Special pots with dual or triple wiper are supported on request. 


Focusrite OctoPre Platinum  
Presonus Digimax FS 
SM Pro Audio PRE 8 E 

Example Setup:


There are several possibilities to control the RGC-24A-M module via MIDI:  

VST-Plugin: The most convenient way, enables seamless integration in Windows audio software like Cubase or SAC.  
Windows standalone software 
Behringer BCR2000 MIDI controller: Templates are available for Behringer's BCR2000 rotary knob controller. 
Yamaha DM 2000 console 
Yamaha 01v96 console 

Manual setup: Gain is adjusted via standard "Control Change" messages. The default scheme is:

MIDI Channel = Preamp, CC = Input, Value = Gain. E.g.

MIDI Channel 2 = Preamp 1, CC 24-31 = Input 1-8, Gain = Value 0-127

MIDI Channel 3 = Preamp 2, CC 24-31 = Input 1-8, Gain = Value 0-127

MIDI Channel 4 = Preamp 3, CC 24-31 = Input 1-8, Gain = Value 0-127 


The Remote Gain Controller RGC-24A-M is capable of controlling up to three preamps (24 channels)  
Up to four RGC-24A-M (96 channels) can be controlled over a single MIDI port (via daisy-chaining) 
Works with most preamp models. The adaption to different preamp models can individually done by the DIP switch (even mixed models). Please send us a mail if you like to use it with a particular preamp (we need only the gain/resistance curve of the original potentiometer). 
The unique, individual sound of each preamp is kept (no changes in the signal path) 
Very low THD+N thanks to special high-class audio couplers 
No hum and noise due to fully isolated design 
Modded preamps retain their original function 
Outputs can be configured as digital switch for reed relays (e.g. to switch pad or phantom power) 
Does not need any power from within the preamp 
Last setpoints are kept after loss of power 
Robust aluminum case 148x94x35mm with mounting flanges, does not eat up rack space 
Quality product „Made in Switzerland“ 




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