GateKeeper Docs
Getting to know The GateKeeper.
Please take a moment to observe INTENDED SIGNAL PATH.
An X indicates a break in the signal when a patch cable is inserted. If a patch point has an X mark next to its name, that will break the intended signal path. There are four main points that do this. This allows you to reconfigure the modules in a variety of ways independent of each other.
For more flexibility there are additional patch points that do not break the signal path. They tap the audio path at select points. This generally does not interfere with the INTENDED SIGNAL PATH
4072 Filter:
Blue LED:
will start to glow as the 4072 filter pushes into saturation.
The 4072 Filter is my interpretation of the classic ARP 2600 filter. I have added some mods and adjustments to push it outside its normal ranges. We have two additional knobs associated with RESONANCE.
AGGRESSION and DRONE knobs take the resonance into more extreme territory you won’t find on the clones or re-issues.
AGGRESSION directly affects the resonance volume compensation. Pushing past the default mark will cause the resonance to start clipping. The high and low portion of the sin wave will be cut off creating a harsher sound. Lower levels of AGGRESSION will produce a milder resonance often associated with east coast synthesis such as the classic Moog filter. The low end and volume will decrease when resonate increases. The default position is closest to the original ARP filter where the signal volume is maintained when resonance is applied.
DRONE increases the higher frequencies to sculpt the overall tone of the resonance. Most notably that soothing spacey tone at lower levels, higher levels can push into frequencies above human hearing.
There are two inputs going into the 4072 Filter. One external output jack.
INS/OUTS
The 4072 IN is connected to the 4072 IN potentiometer. This controls how hard the signal hits the filter. The harder you hit it the thicker and more driven it becomes. Observe the signal icons next to the knob.
The 4072 FIXED (euro) input is balanced for eurorack input signals. That input is also mixed into the filter with any signal present at the 4072 IN jack. There is a small hole bewteen the two jacks. That is the gain trim for the 4072 FIXED input. Don’t mess with that unless you need too.
WARNING!
NEVER ATTEMPT TO ADJUST TRIM POTS WITH A CONDUCTIVE TOOL SUCH AS A SCREW DRIVER! This will cause damage to your unit and possible electrical shock. Instead use a ceramic or plastic tool that is non-conductive.
For the cleanest settings keep the knob at or below the indicator mark. Patch the 4072 OUT X directly into your DAW and you will have the brightest, most accurate ARP signal.
The wave icons show what happens to a sawtooth wave. As you drive the signal it starts to take on more of a square wave characteristic. The square wave characteristic are still “soft” and will not produce the same type of square wave distortion you’ll find in the distortion circuit. This is closer to an analog tape overdrive saturation.