JUNE 24TH 2011
Exploded Drawing #6 (Baby Blue Studios, Austin TX)
A night of solo sets by eminent Texas producers
I will be performing a 20-minute set as BRAINIAX

BRAINIAX - Jakistan :: Respectfully dedicated to Charanjit Singh. I borrowed the bassline melody from his 1982 proto-house track Raga Bhairav. Yes I know he’s Indian, but this track is called Jakistan anyway. This is faux-raga, I’m obviously clueless about classical form. (Eric Archer 2011)

BRAINIAX - Jakistan by Eric Archer

I’m prototyping new analog drums. Listen to the first sounds from the bass and snare drums in this video. Or download the audio from my soundcloud.

BODYTRONIX at Club de Ville by Eric Archer

Denon DN790R + Maxell XLII90 by Eric Archer

Brainclub.us :a limited edition vinyl compilation series
First edition on clear wax featuring a live track by Bodytronix.

Bodytronix - 6AAASP by Eric Archer

Bodytronix - Hydrosphere (extended) by Eric Archer

untitled dec.25.2010 by Eric Archer

…and building this.

UPCOMING

Dec 17th: 6-11pm @ BACKSPIN RECORDS (4631 Airport Boulevard) BEFORE YOU HIT YOUR FAVORITE CLUB ON FRIDAY…. COME SEE: BODYTRONIX / RICKY “SILK” SIMPSON / BILL CONVERSE (-3 TURNTABLE SET-) :: 15% OFF RECORDS AND F**E BEER facebook

Dec 31st: 10pm @ CHEER UP CHARLIES facebook

I compiled a list of recommended books for people interested in DIY music… Circuits for Electronic Music (PDF)

I’m playing three shows in Austin in December 2010:

PLAZTIQX: Dec 4th @ Club de Ville w/ Bali Yaaa, Reaganometry (facebook link)
BODYTRONIX: Dec 10th @ The Loft (718 Congress Ave)… DJ Dance Party + Bodytronix live PA
BODYTRONIX: Dec 31st @ Cheer Up Charlie’s w/ Zorch, Missions, the Sour Notes, No Mas Bodas ++ more!! (facebook link)

I found some mods for the Digitech RDS delay units. This video pretty much explains it. The mods eliminate the lame gaps of silence when buttons are pushed to change mode or come out of bypass mode.”

Bodytronix gettin funky up in a big lotus flower w/ vidkidz and tommy boy on projections (10-23-10). Art Outside is a great festival: a cool mix of retro and futuristic performances, retro carnival midway, camping, lots of good people showcasing their D.I.Y. spirit with creative art installations, and truly fine sound and lighting production.

Here’s the extracted data from all of the sample EPROMs in the DMX.  As explained in the video, these are not playable by standard media browsers.  They are 8-bit files, similar to .wav but with nonlinear u-255 law companding.  This gives them 72dB dynamic range with the appropriate DAC (AM6070) but otherwise they will sound highly distorted without the appropriate u-law transfer function.  Since the AM6070 has been obsolete for decades, there is little hope of cloning the hardware directly.  This situation has also complicated attempts to clone the LM-2 Linn Drum.  All EPROMS in the DMX are 2732 type except the toms, which are 2764’s. The cymbal samples occupy 4 EPROMS each, for extra duration.

Oberheim DMX EPROM data

If you just want to hear the distorted samples from the video, they’re in Samples > Samples_CONVERTED.  Thanks to Todd Bailey for contributing to this.

Here’s the hookup diagram for the boards I tested in the video.

hookup diagram

Schematics for all the DMX voice boards.  Full schematics are available elsewhere on the web.

After a few days of studying and helpful replies from Steve in tech support, I’d figured out Lattice Semiconductor’s free design software ispLEVER Classic, and successfully downloaded a simple ‘hello world’ demo to a Complex Programmable Logic Device (CPLD) chip. My highest hopes were confirmed… all the steps are possible without writing a line of code. Hooray! You can draw a schematic on the screen and transform it to a piece of hardware in seconds. What a futuristic feeling. The chip itself is some kind of silicon fabric made of zillions of nano-size zombies that reconfigure themselves on command…?! anyway, I’m not scared.  Indeed I’m thrilled with the power of this technique.

The software is free, its called ispLEVER Classic 1.4. Installing it on my Vista laptop wasn’t quite a snap because there are three or four modules to install in order, and you need to find your computer’s MAC address to activate the license. I have to use ‘run as administrator’ to launch it too, but whatever.

The programmer is called ispDOWNLOAD, and it was about $175.

The CPLD chip is ispLSI2032VE, actually nearly obsolete now but the software still supports it.

I think soon I will try to understand Lattice’s MachXO series. They’re related to FPGAs, have built in dual-port RAM, clock generator, clock multiplier… a nice toolbox.

Its inspiring to think that even if the schematic in your head is extra complex, you can just draw it and *boom* little elves build it for you in seconds.

Of course its limited to digital circuits. Not analog yet…

Closeup of the breadboard adapter.  In addition to the socketed CPLD, it has a JTAG 2×5 programming header, a 3.3V regulator, three capacitors, and a resistor.

Note on clock rise times:  CPLDs are capable of running very fast clock rates, 100MHz+.  In my example circuit shown above, I found the counter was behaving anomalously, skipping states.  The root of the problem is related to rise time of the clock pulses.   Logic can be 0 or 1, but the rise time is how long it takes for a transition to occur.  Imagine a horse race and everybody is on the starting line ready to go… the flag goes up, but very slowly.   Will everybody start at exactly the same moment?  This is an analogy for clocking the CPLD.  I found that clock sources that worked fine with 74HC TTL and CD4000 CMOS often do not have a quick enough rise time to clock this CPLD without glitching.  The clock generator built in to my old-school Knight breadboard has a 150 nanosecond rise time, which is too slow.  Experimenting, I found that 10 nanoseconds appears to be fast enough for reliable clocking.  A 74HC244 buffer IC works well for conditioning real-world inputs.