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 two main flaws to this 8038 oscillator design
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 2nd and 4th octave will be a couple cents off.
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
im building up an email list for notifications on new product releases and sales
3hp Skew Fade LFO coming out March
my 4hp SVF is making a come back in March as well. details and videos coming soon.
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
Push VCA: 2 independent unity gain dc coupled VCAs with led push button switches to turn channels on and off in 2hp. a mix of both channels is available at the sum. all outs are available simultaneously.great for cv or audio.
aluminum panel. reverse power protected. current consumption +12v @20ma, -12v@ 20ma
MiniAtt: is a 2hp dual passive summed attenuator with toggle switches to turn each channel on or off. both channels are normalled to the sum. there will be some signal loss at the sum out, as the module is passive. great for cv or audio although the module ships with linear pots.
aluminum panel. passive, does not consume any power.
Żłob Modular T-shirts are available in medium, large, and xl
they are %100 preshrunk cotton
please put your desired size in the paypal notes or email me
shirts come in red and black now. black shirt with red screen print(not pictured, but same logo)
I have some new 2hp and 4hp blanks for sale also. the designs are based on a turkish carpet motif representing ram horns: a symbol of power…
Blanks are black and white pcb panel now(not pictured yet)