The Skew Fade LFO is a 3hp all analog low frequency oscillator. It has three rate settings capable of 3 minutes and 30 seconds a cycle up to audio range at 20 hz. Triangle waves can be skewed between saws and ramps, and square waves pulse width can be adjusted. The LFO’s unique feature is voltage controlled cross fading between skewable sine and square waveforms. Bicolor led provides constant display of positive and negative voltage crossings.
10vpp waveform outputs
+12v: 15mA, -12v: 15mA
The Dual VCO is a 4hp dual voltage controlled analog oscillator. Each VCO has square, triangle, and sine wave out, coarse and fine tuning controls, a control voltage input, and a switch for selecting exponential or linear cv in.
When a control voltage is inserted, the fine tune control becomes an attenuator for the incoming voltage. In exponential mode, when the attenuator is fully clockwise, the VCO will track around 5 volts per octave.
Each VCO runs from 0.2 hz (5 seconds a cycle) up to 18k hz
Very Stable, Temperature compensated
waveform outputs 10vpp
current consumption: +12v 20mA, -12v 38mA
There are a couple quirks to these 8038 VCOs
Below 300 hz the waveform symmetry is slightly off. triangle waves get a little uneven in the lfo range, the sine is not completely perfect to begin with the bottom trough and in the lfo range it slopes slightly, and the square turns more trapezoidal above 1khz(see scope shots)
Also it doesn’t track 1 volt per octave perfectly. usually the 1st and 3rd octave will be a couple cents off.
In linear CV mode, the incoming voltage is inverted. So, a positive voltage will actually make the pitch go down. The fine tuner also respond inversely, as it’s turned clock wise the pitch goes down.
Other than those idiosyncrasies, it is a powerful, stable dual oscillator in a small footprint with no cross talk between oscillators. It’s great for: drones and beating sine or triangle waves, cross modulating itself for interesting clocks/LFOs, creating complex waveforms/timbres through lin/exp frequency modulation.
(pcbs come with smd matched transistors pre-soldered)
VnIcursal t-shirts are now in stock. they are preshrunk 100% ringspun cotton available in medium, large, xl, and xxl for
please send a follow up email to email@example.com for what size you want
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3hp Skew Fade LFO coming out April
Entropy 2 (in 3hp) is coming soon. upgrades include a manual switch for toggling between sample/hold and track/hold, and an improved infra out(low frequency random) with manual switching between slow and fast random slopes.
Knurled Nut drivers for qingpu/thonkiconn style jacks are available in limited quantity for $10 each
VnIcursal top pcb upgrades are now available. the new top pcb adds attenuation functionality to pre-existing v3 and v4 vnicursal mother boards. so when cv is inserted into the cv jack the pots now become attenuators for the incoming voltage.
a couple things to note: the older revisions are not designed to have the leds turn on close to the 0v crossing. this means there will be a small range of the pot turn where you will be able to hear sound and the led is not on. also since the leds are on more now the circuit will consume around 10-15 mA more on the +12v rail.
and finally some resistors will have to be substituted on the mother board for optimal operation. depending on what version you have you will have to replace six 47k resistors with six 62k resistors or six 75k with 62k. this will give you unity gain at 5v. i will post a pic soon of where those locations are. it isnt completely necessary for the mod but if you dont do it you will notice towards the end of the pot turn the circuit goes from distortion to an almost waveshaping pop.
VnIcursal top pcb upgrades: $10
all modules not already in red/black aluminum come with black and white aluminum pcb panels. replacement panels are also for sale.
attmix b/w panel only
dual vca b/w panel only
entropy b/w panel only
clk dv b/w panel only
mineq b/w panel only
aluminum panels are in for the vnicursal vca. and 2 new 2hp modules are out now(see below).
Vnicursal VCA aluminum panel: $10