Pulse Width Modulation

Posted on January 22, 2011 by John C.S. Keston

I setup and recorded this example of pulse width modulation using my Roland Juno-106. I started out playing an octave with the pulse width set to half way. Next I moved the pulse width up and down covering the full range possible. Eleven seconds into the recording I enabled the LFO on the pulse width and adjusted the speed of the modulation all the way up and then all the way down again. The picture shows the LFO in action. Notice that the LFO operates as a triangle, but with slight curves on each slope, which is probably a result of the analog circuitry. Here’s what it all sounded like.

Upcoming DGK and Ostraka Performances

Posted on January 22, 2011 by John C.S. Keston

Here’s a list of upcoming performances from my trio, DGK (Davis, Glenn, Keston) and my solo project, Ostraka. First up is DGK at the Turf Club in St. Paul, Minnesota on Friday, January 28, 2011. Also on the bill is Dosh and H.U.N.X. Doors at 9:00pm. $5.00. Main stage. Next up is Ostraka at Nick & Eddie Thursday Funhouse on February 3, 2011. Doors at 10:00pm. Located in the back bar. Free entry. Thirdly we have DGK at the Red Stag Supper Club on Monday, February 21, 2011. Doors are at 9:00pm. No cover.

Generative Sequence Driving MDA JX10 Emulator

Posted on January 21, 2011 by John C.S. Keston

I created the following generative sequence using GMS (click for details), during a solo performance at the Spark Festival of Electronic Music and Art, October 2010. One of the virtual instruments I used in the set is an Open Source, Roland Super JX10 emulator made by MDA. The Roland Super JX10 was one of the last great analog poly-synths produced by Roland, and the first Roland synth to receive velocity and aftertouch treatment on the 76 key keyboard. Although I never owned one of these, I have played one before, and I imagine that programming them was brain surgery without the optional PG-800 programmer. In the documentation for the MDA JX10 they state, “[this] plug-in is designed for high quality (lower aliasing than most soft synths) and low processor usage – this means that some features that would increase CPU load have been left out”. To me this plugin sounds very good. I’d like to hear from anyone who owns or has played a Roland Super JX10 for their perspective on this instrument.

MDA JX10 Emulator

Korg Monotron Clip from Live Set

Posted on January 20, 2011 by John C.S. Keston

Here’s a sound I coaxed out of the Korg Monotron during my live set at Nick and Eddie Thursday Funhouse that I mentioned in the last article. One again, you can download the entire set here. In my previous demos of the Monotron I used no processing, so this time I decided to present it exactly as it was performed in the live set, through stereo delay and reverb sends. The sound of this minute instrument never ceases to amaze me.

Monotron Clip

Grain Machine Sample from Live Performance

Posted on January 19, 2011 by John C.S. Keston

Here’s a sound I produced during a live set at Nick and Eddie for the Thursday Funhouse series under my Ostraka moniker. You can download the entire set that I released as a holiday gift last month. I used Grain Machine which is a touch based granular synthesis instrument that I developed in Max for Live to create the sound. Grain Machine requires a device running TouchOSC such as an iPhone, iPod Touch, or Android device for the touch based control. There’s a rotary wheel with friction modeling, and an x-y pad for granular exploration.

Grain Machine from Thursday Funhouse