A little modular music

June 12th, 2014

idea sketch ES 14.59 from Kurt Kurasaki on Vimeo.

I’ve been creating and archiving quite a few of these little modular pieces for the last year. This is one of the latest patches that utilizes modules from Make Noise, Verbos Electronics, Livewire, and Music Thing / Thonk. The patch is fairly pre-set, relying on a couple of base sequences that are scanned at random rates based on values generated by the Livewire Chaos computer. The oscillators are inter modulating to dynamically change timbre, and one sequence also drives the minimoog model D that provides the backing pad. Most of the build up and breakdown is manual tweaking of dynamic and timbral controls for a sense of live performance, but the notes and sequence themselves are random.

Bad Power Cable - Almost Destroys Gear

April 18th, 2014

This is yet another one of the various nightmares one can encounter when dealing with audio hardware. While patching my Eurorack modular rig into a tube mic pre, I felt the light buzz of an electric current passing through my fingers. Obviously, this is not a good sign, and it means something is terribly wrong. After disconnecting everything except power, I tested for voltages across grounds and discovered a 120V AC difference between the tube amp ground and the Eurorack case. As it turns out, the problem was the IEC power cable… yes, that unassuming three conductor cord that connects to the power main was at fault!

A continuity test revealed that this cord is essentially cross wired. This means the Neutral from the mains is connected to the Load of the IEC connector and the Load (Live wire) from the mains is connected to the Neutral. In the photo above, you can see continuity between the Load contact and the Neutral on the IEC connector. Even with the synth switched off, power was running into the system, and a bit of current was finding it’s way to the panels and case.

Unfortunately, I have no idea how this cable was acquired. It was just in the box of power cords, and presumably correctly assembled (how the heck can you mess up 3 connections?) The cord is labeled, “PVC YOUZHI DIANXIAN 3C RVV 300/300V,” and it’s missing the country of origin. A quick websearch reveals that it was manufactured in China, and YOUZHI DIANXIAN is known for other substandard cable products.

The good news is that the synth and tube amp are fine, but i ran into problems with some other audio gear. A few components are blown (again) in my monitor control system, and I need to check on some vintage compressors. I’m just lucky that it didn’t cause more severe problems like data loss or death :-/

Cable has been properly destroyed, and is ready for recycling! Moral of the story: always use the IEC cable supplied with the gear or test the contacts to make sure they are not crossed before you connect to the mains.

Cassette Recording Audio Processor Rack Extension

April 1st, 2014

The Cassette Recorder Audio Processor Rack Extension is an analog emulation effect for the Reason Rack that will enhance your audio with the smoothness and colour unique to analog recording. Yes, CRAPRE adds the warming sound of ground loops and tape hiss while enhancing incoming signals with harmonic destroytion! Our crap staff of mad nerdbags has discovered a special undocumented feature of the Rack Extension SDK: a colorful user interface with pink knobs, kittens, rainbows, and unicorns optimizes CPU usage while psychedelically extending the digital music stuff from 32 bit to a whopping 41 bit super-endian-rainbow-floatiger maths! In laymen’s terms, this means Crapre sounds terribly good! The wow and flutter algaerytm adds a deluxe warmingness, and it even simulates “tape eating” for hi definition low fidelity realistic results!


Tesla Coil Samples

February 27th, 2014

For those who follow my social media streams, you may have already seen the various DIYAudio, DIYSynth, DIYrepair projects going on around here for the past year. One of these projects is the oneTesla Musical Tesla Coil kit. In “synth speak” it’s essentially a pulse wave oscillator. The oneTesla incorporates an arduino brain that receives MIDI note information, and the sparking plasma threads emitting from the coil oscillate at musical pitches. I certainly recommend the kit if you’re looking for a fun weekend project, however it may require some debugging and may also require the need for a function generator and oscilloscope. Over the past year it seems that the development team has ironed out the kinks in the design and even novices generally have great success in their builds.

The link below is an archive of the multisampled notes generated from the oneTesla. I’ve provided the archive as a folder containing an NN-XT patch. The audio was recorded at quite a distance from the Tesla coil, mainly because I didn’t want the coil to discharge through the microphone, but also because the output is incredibly loud. The recorded results aren’t as impressive as having the real-time audio-visual experience, so get a better “feel” of the actual sound, it’s recommended that you run the sampler output into a peak limiter and push the gain up 3dB to 9dB, and play the samples back at very high levels. The coil is sampled note-by-note from MIDI C0 to C5, and you will hear “spark” artifacts and a few obvious loop edits.


Alias8 CV Modular Patch Challenge!

February 24th, 2014

Thanks to all those who participated. We now have a winner!

Modular Patch Challenge

Alias8 CV Controller Rack Extension

January 8th, 2014

The Alias8 Rack Extension is all about control. Place the device at the top of your rack, route some connections, customize the labels, and start tweaking. Once your routings are configured, you no longer have to scroll through to find that all important filter knob or trigger button in your complex rack setup.

The Livid Instruments Alias8 inspired the idea of having a Reason Rack Extension that visually mimics a hardware control surface and seamlessly integrates remote mapping; bridging the gap between you and the Reason rack. This collaborative effort with the good people of Livid Instruments has resulted in the ultimate virtual control interface, the Alias8 CV Controller!

Available from the Propellerhead Shop

Example Reason Files

Loop Launch and Live FX: Alias8-REXandFX.reason.zip
Alias8 Modular Style Song Demo: Alias8-stockdevicedemo.reason.zip
Granular Sample Manipulator with Buffre Beat Repeater: Alias8-BuffreConcrete.reason.zip

Operation Manual

Detailed Documentation which includes various example projects is available from the following link:

Alias8 CV Controller Operation Manual

Version 1.0.1 PDF Download. Requires Adobe Acrobat or other PDF Reader

Livid Instruments Alias8 Hardware Controller

The Alias8 Rack Extension works seamlessly with the Alias8 Hardware controller through Reason Remote scripting. There’s some basic setup required as well as a recommended firmware upgrade. For more information, please visit the Livid Instruments Reason Support Page

For more information about the Alias8 Hardware Controller, visit the Livid Instruments Website

Korg MS-10 Ressurection

August 29th, 2013

Last winter, my friends, Ryan and Lisa came for a visit and brought along a Roland TR-606 and a Korg MS-10, both of which were not working.  The 606 was easy to fix since the lead to the battery compartment had come loose.  The MS-10, however, was a completely different story and required a lot more research since I’ve never undertaken a repair like this before.   I’ve managed to get the MS-10 back up and running, and I want to share some of this information, just in case someone out there runs into a similar situation.

The Korg MS-10 was purchased in Europe but came with an unpolarized NEMA AC connector that looks like it would work in Japan or North America.  When Lisa and Ryan used this in Europe, they had it connected to a power adapter which bucked the voltage down from 220V.  After moving to the US, they (Ryan) plugged it into a regular 120v socket, and it started smoking.  Since then it has been dead.  Whenever I would visit their home, i would see the dead little MS-10 sitting as a bit of decoration on a table.  

About a month ago, this project seemed like it was ready to be tackled.  Fortunately, the service manual is available from several sources online.  Synthfool is not only a great synth tech, but provides the community with the archive of these materials.  After studying the schematics I started to open up the unit and noticed something odd.  The badge says it’s requires 15 volts ac.  This was a head scratcher, and I thought perhaps it was a misprint and should have been stamped 115 rather than 15.  It simply makes no sense especially since it has a NEMA plug.  

So after opening up the unit, I discovered that the transformer is basically used as a coil.  The incoming voltage from the AC line runs into one leg of the primary then passes through the other leg of the primary right into the motherboard.  The other leg of the AC line passes into a fuse (which was blown) and the power switch then into the motherboard.  I was expecting to find a normal AC connection where the incoming power connects through the fuse and switch to the primary of the transformer, and the secondary windings of the transformer passing to the motherboard.  However the way this was wired, the badge was indeed correct, and it was intended to run off of a 15 VAC power source… not 220/240 or 110/120vac.  When the MS-10 was plugged into a socket, 120 volts was sent straight into the motherboard and did some serious damage.  

At first, i thought maybe I can get lucky and just replace the rectifier diodes and the 7815 and 7915 voltage regulators and it will be done.  I pulled the diodes and regulators and found that the diodes were OK, but the regulators were shot.  Fortunately a these components are easy to get, so I popped in the new ones and started to see some signs of life.  The LFO light started blinking, and I could hear some noise.  The keys wouldn’t play, but after patching the LFO into the VCA, I could hear some activity and I could adjust the filter into self-oscillation.  While far from being perfect, there were some signs of life, and I figured, why not push forward to see how far I could get.

According to the schematic, the MS-10 oscillator section takes power right off the transformer… however in this case, 120VAC was injected into this part of the circuit.  This would be good place to start looking.  Sure enough some of these FETs were damaged and replacing them got a 60Hz hum being shaped into a sawtooth and pulse, however the envelope generator and keyboard were still not working.  It dawned on me that half the AC leg might have still been active after the fuse blew, so there was still a lot of voltage passing through the circuits and to ground through the audio out socket.  It made perfect sense that the CMOS components were damaged and many of the op-amps (TL0s, etc).   After replacing many of these more sections started to function.  The envelope generator, the modulation routings, etc.  Sure enough, after replacing all of these components everything came back to life!

Thinking that a critical component might have been damaged, i also sourced a special NPN transistor pair (2SC1583) at the heart of the oscillator.  This part is also used in the TB-303 and x0xb0x and has become rather difficult to find.  To make matters worse, according to a thread on the adafruit forum, counterfeit versions are floating about, so i avoided the foreign eBay suppliers.  As it turns out, the original transistor was not damaged.  I popped in the new transistor, and I was surprised that there was a bit of a difference in sound.  The original transistor has a bit more character and bite, so i put it back in.  I’ll keep the spare in case one of my old synths needs work.

I thought about properly wiring the transformer back into the circuit, but instead opted to leave the power section untouched.  This particular MS-10 still runs off 15 volts AC, but the original power cord has been removed and replaced with a 2.1mm power jack and a wall wart.  Hopefully this mistake will not be made again in the future.   The moral of the story is this:  Yes, apparently Korg made some MS-10s and MS-20s that were designed to work on 15VAC, but have a North America AC plug.  If you plug one of these 15V units into a 100/110/120 socket, it will definitely fry.  If you’re in Europe and plug it into a 220/240 to 120 converter, it will fry.  

I tracked some raw samples of the unit.  You can download the Reason session here:

and a short video: