GateKeeper Docs
OVERDRIVE AND FREQUENCY BOOST
OVERDRIVE toggle hits the 4072 filter much harder than the 4072 IN potentiometer. The resulting distorting can add definition and tone.
FREQUENCY BOOST will add a fixed frequency boost around 6500 cycles to the MULTA FILTER. This is not dependent on the MULTA FILTER potentiometer position and will be filtered out when the filter is turned down. It will also increase the MULTA RESONANCE response.
This adds a little sparkle to the top end of the INTENDED SIGNAL PATH. It can help darker synths like a Moog Subsequent 37cv seem brighter while the MULTA filter is fully open. It can also enhance OSC NOISE MODE A.
CV CONTROL
*The orange LEDS indicate GATE and the amount of the ADSR envelop hitting the filters.
THINGS TO KNOW
GATE is a “universal” gate input. Any approximate gate signal of about +2.5 volts should be enough to trigger the ADSR envelope. Even a square wave LFO works as long as it’s in a positive range.
**The GateKeeper uses an AS3310 ADSR chip. It turned out to be finicky. Our Moog One put out a soft gate signal not sharp enough to trigger the envelope. On the opposite side the little Behringer Pro-1 also didn’t put out a suitable gate signal ether. Some companies make modules that convert gate signals into the proper shape and voltage to overcome this.
That has been built into the GateKeeper.
TRIGGER will re trigger the GATE while the gate signal is positive. More of a legacy feature but still useful if you have the gear.
DECAY will modulate the DECAY section of the ADSR. In my opinion this gives a much needed variation to your sequences. Patch in an LFO.
ADSR commonly known as ATTACK, DECAY, SUSTAIN, RELEASE. It’s an envelope. Its triggered by a GATE signal …you know what this does.
4072 CV and MULTA CV MODULATION These patch points will cut the normalled ADSR envelope and route your external modulation into the corresponding CV potentiometers.
4072 and MULTA FAFO/OCT these patch points are fixed and merge your external CV with your ADSR envelope CV. They do not route into the 4072 and MULTA CV potentiometers. If you want to decease the external CV amount you’ll need to use external attenuation.
You can use these CV inputs while the filters are self oscillating. The RESONANCE will track 1 volt per octave over several octaves. …mostly. That’s something you need to FAFO for yourself.
ENVELOPE POLARITY this flips the positive voltage of the envelope to a negative voltage. You will need to keep this in mind. **Your filters will work in reverse. Rather than applying the envelope to a closed filter try opening the filters and then applying the negative envelope.
ENV-OUT This will let you send your ADSR to other modules. Using this will not interrupt your internal envelope. Try sending this envelope to another RMLfx filter module like the 432k Rev2 or the Hyde Distortion Filter.
Check back for more updates later.
**Special thanks to Dave Seidel for providing several important corrections that significantly improved this document.