→Internal Normalisations: - added a new connection
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[[File:RobHordijk-TriLF-VCO.jpg|thumb|Photo of a Rob Hordijk LF-VCO. (Photo by Todd Barton)]]The '''
=== LF-VCO A ===
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=== Sample & Hold Function ===
In new versions the modulation input of '''LF-VCO C''' has a S&H right after the input connector, but just before the input level knob. '''LF-VCO C''' triggers the S&H circuit.
The S/H is triggered every change of direction (rising to falling, or falling to rising)
On every positive peak and on every negative peak of the triangle waveform the S&H samples the '''LF-VCO C''' modulation input signal and holds the sampled value during the slope that follows. This means that the S&H causes every up-slope and every down-slope of the triangle to have a different duration, defined by the momentary value the S&H happened to sample. The slopes remain perfectly linear, only their steepness is affected. The effect is that there is a more or less random spread in time. This also effects the duration or width of the pulse output.
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To use the S&H modulation on LFO C it is often a good idea to not set the LFO C rate knob to its maximum. While there are not set limits for the minimum rate times, a very large negative modulation signal can cause a LFO to stop oscillating. If this happens when the LFO C rate knob is at its minumum, the modulation level knob is fully open, and a sampled negative signal is stopping the LFO, and thus also not sampling a new value that can start it again. In this case LFO C may appear to be frozen. In that case you can just open the rate knob a bit until it starts oscillating again. Or wait for a very long time for the S&H capacitor to eventually loose its charge.<ref name=":0" /> [[File:Hordijk trilfo.png|thumb|200px|Panel design for a Rob Hordijk TRIPLE LF-VCO]]
=== Internal Normalisations ===
Many of Rob's designs feature internal connections or 'normalisations' between inputs and outputs. These can be broken by inserting jacks into the inputs. When found together in triple-module formation the following normalised connections were made:
* LF-VCO
* LF-VCO - C
* LF-VCO - A
* LF-VCO - B PULSE output > DUAL ENV - GATE IN
This means that when no external signals are applied to the inputs, and their modulation input level knobs are opened, LF-VCO A and LF-VCO C
== External Links ==
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