crOwBX 2.4 Voice Card. First Test

Published on May 27, 2020 TjimmyChonga

"Here's a first test of a crOwBX 2.4 voice card using a custom digital controller board.
The crOwBX is a clone of the legendary Oberheim OB-X, and one day I hope to finish a digitally controlled OB-X clone, using the crOwBX voice cards, but adding additional features, like multi timbral, modulations, etc.
This is not something I anticipate being done soon, given that I got these voice cards two years ago, but one day... In the meantime I keep changing the scope of the project so I'm not in a hurry."

crOwBX demo - DIY Oberheim OB-X clone (4 voice polyphonic)

Published on Apr 4, 2017 der oberling

"I recently finished my crOwBX synthesizer to the point that it's finally playable.

My previous demo only featured an uncalibrated single voice ([posted here]). This demo utilizes the whole 4 voice calibrated analog power of the beast.

Since I'm no keyboard player I prerecorded some notes and chords in ableton, corrected them, quantized them where needed an played them back looped - sorry for that :-)

The signal is completely dry - the crOwBX all by itself through my Focusrite Scarlett 18i6 into Ableton. Only the last bit got a little MIDI-Clock synced LFO from my MIDI-CV unit ;-) .

A unison demo is yet to come... It's a little challenging to keep the 15 minutes limit.

This project was "in the making" now since 2013. That's mainly due it's over 3000 parts to solder, debugging, initial calibration (which is really excessive) and finally I wanted to develop my own MIDI-CV unit for this which I did. All in all it's very rewarding to have it all up and running finally and it sounds gorgeous to my ear - but listen for yourselfs :-)"

Crowminius Demo

Published on Mar 4, 2017 kpsiegel

"This is a demo that was done by request of the Crowminius synthesizer. This was a Kickstarter campaign [see here] done by Scott Rider (aka Old Crow.) This synth clones a Model D in a nice case with some added features such as PWM, MIDI, and separate outputs that you can loop back to audio in to overdrive the filter. You can see I have that hooked up with the bright orange cable.

This was recorded completely dry and was not EQ'd at all. I wanted to show the synth itself pretty raw. The Crowminius was driven by my GRP R24 sequencer using the CV and Gate outputs to the Crowminius. I could have used MIDI but decided not for this demo. The sequence was just an F mixolydian repetitive 16 notes so that I could focus on showing the sound as quickly and efficiently as possible. I flip between the different wave shapes and open and close the filter as well as playing with envelopes and depth. You can hear the difference on the pulse waves when I bring PWM in and out of the sound. I tuned oscillator 2 a major third up from the primary oscillator.

I am sorry the video sort of cuts out to a still photo toward the end but my video camera ran out of batteries while recording. The plus is you can see the controls of the Crowminius."

Previous posts: http://www.matrixsynth.com/search?q=Crowminius

Oldcrow Modular GX1 Bandpass Resonator Filter Demo

Published on Feb 17, 2017 musiqfreq aka Qfactor

"A test of the GX-1 Bandpass Resonator designed by Oldcrow Modular"

The GX-1 is of course the Yamaha GX-1, pre-curssor to the CS80.

Crowminius Rev. 1.1 PCB Unboxing 2015

Published on May 4, 2016 fredturd

"Update: Kickstarter Campaign here: https://www.kickstarter.com/projects/...

Ends Saturday, June 4, 2016

Scott "OldCrow" Rider's one-board minimoog PCBs showed up on April 16, 2015. I actually uploaded this back then, but I had to make an edit to hide my address - don't want too many fine babes stalking me..."

Quick Crowminius Synth Demo. Dr WHO theme

Published on Apr 16, 2016 Mindburner

"demo done on the Crowminius synthesizer. Lead using 3 oscillators."

The Crowminius is currently seeking funding on Kickstarter here.

Very quick and dirty Crowminius demo. This is an excellent minimoog PCB, designed by the Old Crow

Published on Feb 12, 2016

"PCB designed by the Old Crow. This excellent minimoog based synth is a very cool operator. Very faithful replication of the original model E. Lovely bass and nice leads. I built the PCB into my own case and designed panels. It also has a sequencer included. I was going to add a RAT distortion and space echo but basically ran out of internal space."

The Crowminius Desktop Analog Synthesizer Now on Kickstarter

You might remember Scott Rider's (aka the Old Crow) Crowminius from back in 2015. It is now on Kickstarter seeking funding. Click through for full details and funding levels. The Crowminius is a Minimoog inspired analog monophonic synth.

Some details captured for the archives:

"The Crowminius is a desktop analog monophonic music synthesizer built in the spirit of Dr. Moog's famous Model D.

The Crowminius is a complete desktop monophonic analog music synthesizer inspired by Dr. Robert Moog's legendary Minimoog model D. The Crowminius is constructed from standard components with no esoteric parts and is fitted into a sleek aluminum attache case for easy portability.

The Crowminius features an Atmel MIDI control front-end based on the ATMEGA328P chip, the same as used in the popular Arduino Uno. The open-source firmware supports MIDI note, velocity and aftertouch as well as MIDI pitch and mod wheel support. An optional LCD can be installed to monitor system functions but it is not necessary. In the case of interfacing with vintage pre-MIDI gear such as the classic Minimoog, modular synthesizers and modern instruments that offer the necessary control signals, the unit can be operated from pitch control voltage and choice of voltage trigger or switch trigger jacks.

The Crowminius features three full-range oscillators (tone generators) that each can be set via rotary switches from sub-sonic frequencies through a set of "organ stops" (octaves) from 32' (bass) to 2' (high soprano). Each oscillator has six waveforms also set by rotary switch to provide the harmonic spectra used to create various sounds.

Oscillators 1 and 2 each feature individual pulse-width modulation generators--a feature not found on the vintage model D--and oscillator 3 can be set to act as a "control oscillator" to provide vibrato and filter modulation by use of the on-board modulation control or by MIDI modulation commands from a remote controller.

The Crowminius has an on-board white/pink/red noise generator that can be used to create audio effects such as wind and surf sounds, but the noise source can also be used as a modulation source. Another feature included on Crowminius that makes use of the noise generator is a "sample/hold" circuit that uses oscillator 3 in control mode as a clock to trap the noise signal levels and provide a series of stepped random modulation voltages.

These signals are all presented to the 4-pole ladder filter and control amplifer, an all-discrete transistor (no chips!) circuit combination that defined the sound of 1970s progressive rock. The filter has dedicated controls for tracking and modulation, and the filter and amplifier each have their own contour generators to control the dynamics of your sound.

Other features include an external audio input into the filter, a "locking" portamento/glide circuit for moving from note to note in solo style, and a "decay mute" feature which allows immediate muting of notes when keys are released. Both the glide and decay mute functions can be operated by external footswitches if needed.

Finally, two essential performance features are provided. A reference tone at A-440 ("concert A") can be enabled for precise instrument tuning. This tone is created by the microcontroller using a direct-digital synthesis algorithm that outputs a very accurate PWM-modulated sine tone. Secondly, a dedicated headphone jack and headphone volume control allow the performer to mute the instrument, set up a new voice patch, tune up and and un-mute right back into a live session without disrupting the performance.

The entire Crowminius system is powered from a single 12VAC, 500mA wall-pack power supply, with provision to allow the use of two supplies for improved supply operation.

The best part about all this is: the Crowminius already exists! The Crowminius was originally presented as a DIY project to synthesizer enthusiasts in early 2015, but as so many people have asked about a pre-assembled version it was decided to offer a production run with an initial goal of shipping 100 units. To this end the design has already been reworked for surface-mount assembly, with the production prototype being hand-built and fully tested before committing the SMT assembly line to production.

More information is online at http://www.crowmini.us/"

crOwBX uncalibrated single voice demo

Published on Jul 23, 2015 der oberling

"single voice crOwBX synthesizer - uncalibrated

sequenced by my minibrute

further modulation via VCO-2 in LFO-Mode of my TTSH plugged into various inputs;

completely unprocessed (except for fade in and out :-) ) - crOwBX outputs go straight into inputs 1 and 2 of my Focusrite Scarlett 18i6, recording in Ableton Live, Video Processing in kdenlive

The crOwBX is a analog polyphonic synthesizer and it's voice cards are clones of the voice cards of the Oberheim OB-X

PCB and FrontPanel designed by Old Crow (small addition to the FrontPanel by deroberling); this unit is proudly assembled by deroberling;

further information on the project: http://www.cs80.com/crowbx/"

The Crowminius Synthesizer - "Crow’s Mini for the Rest of Us"

via Adafruit

"Hey folks, Crow here. As I may have mentioned in the past my first hobby is electronic music synthesizer design. While a fair amount of my spare time these past two years involves the crOwBX project [featured here], I did manage to work out the design for a new instrument. The two main driving forces behind this project were wanting to make a replacement machine in the style of a Minimoog 204D ('model D') for my good friend Doug Ferguson, who lost his circa 1974 original Mini to hurricane Katrina, and I wanted to create a machine that would fit in the compact aluminum attache case as used with Dan Alich’s awesome Duinokit. Thus was the Crowminius synthesizer born. (Doug calls it 'Crow’s Mini for the rest of us.') The schematic capture and board layout took about 10 days, with 1,457 airwires to sort through for the approximately 800 parts. (I do not use autorouting: autorouters suck.)"

Old Crow's Oberheim OB-X Clone Project

via oldcrow on Muff's

First post with initial diagram above: "Ever since playing MC's OB-X at AHMW, I got it into my head to try and make one--gotta be cheaper than ebay! This meant making my own voice cards, first in the original form factor to test first on a "host board" to power and provide pots and switches for the voice board under test, then later in an actual OB-X. Since the vintage cards used CEM3310s and discrete everything else, I made the EGs in non-custom form using JH's VC_HADSR as a design reference (it was inspired by the 3310). It works on a breadboard, so they're in the CAD schematic and the "hard" part of the layout is done: the VCOs. I squashed the circuits a bit in order to open up some room on the board as my EGs were going to be a tad larger than a single 16-pin chip; they each use 4 chips, 4 transistors and a handful of passives. Throughhole parts as my eyes have gotten too bad to hand solder SMT very well (but I have a full SMT factory line for that if I ever make more than 8 of these ;)

The CA3080s are replaced by 13700s, which are dual 3080s. I do not bother with the darlington buffers. The CA3086 transistor array is replaced by two LS318s, and those mount over SMT TC resistors (see A3A, A3B in image). I do use some SMT bypass caps as the original board features no bypass caps whatsoever, save for the DC filter caps on the local voltage regulators."

Follow-up with the pics below: "Slowly the master vision takes shape: here is a nearly-finished host board with a fully-populated carrier board mounted to it, and the carrier board loaded with a slot adapter and attached crowbx voice board."

For those not familiar with Old Crow, you can find his site here. He has been most often referred to here on MATRIXSYNTH for his KORG Polysix battery fix.

CLICK FOR MORE »

Gallows In The Light Of Dawn with the Scott Rider GX1 VCF

Published on May 20, 2013 JohnLRice·201 videos

"Testing out my new GX1 VCF from Scott Rider (AKA "Old Crow"). You can buy one here.

It's a really nice and expressive band pass filter.

Other modules used are my usual compliment of MOTM VCOs (5 total used here, one for the lead voice, 3 for the drone and one for the sequence), VCFs (440 for the sequence) EGs, VCAs and MIDI to CV. In addition a STG Sea Devils VCF was used for the drone, a Moon 569 sequencer for the sequence of course and a COTK delay. Roland products used included a FantomXR synth, RSP-550 effects unit (reverb) and M-120 mixer.

Background video clips licensed through www.pond5.com

Item #23150497
Sunrise in the wood

Item #11346833
Aerial view of gallows

Item #12800351
Driving on night road

Item #23416265
The Milky Way rotates around the pole star, then dawn"


"This is the bandpass filter that had its own signal path from the sawtooth output of a GX1 voice's VCO to select specific harmonics from the waveform. In the GX1 this resonator had a fixed Q of 5 but this has been made variable (0.5 to 15) in the module. This was a "side chain" signal path to the primary GX1 voice that uses the NE10400/10500 filters (which I turned into the MOTM-485) that the Electone design team--organ builders, remember--used for enhancing various reed, brass and string voicings remade as a standard 1U x 5U module. Has power connectors for both MOTM and synthesizers.com power cables. Note: mounting screws and power cable not included."