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September 22, 2007

Oberheim Two Voice demo

After wasting a couple days on the aforementioned Opcode Sonicport project I was finally able to import audio from my DAT player to replace the woeful audio the camera's built-in mic captured. I recorded 15 minutes of various Oberheim Two Voice noodling to show off what the combination of two SEMs and a sequencer can do. I broke the video up into segments. This is the first of several.

Posted by cary at 11:29 PM

Opcode Sonicport Info

I picked up an Opcode Sonicport SPDIF to USB audio interface many years ago. The Windows 98 driver and config application were always a bit sketchy and didn't get a chance to improve as Gibson purchased then disbanded Opcode. As far as I know there was never a release of the config app that ran under Windows 2000 or XP. Since I didn't like the idea of keeping a Win98 host around for eternity I poked at the internals to see if it's possible to change from analog to digital I/O without writing a config app.

The device uses a Philips/NXP UDA1335H USB to analog and I2S bridge. SPDIF to I2S conversion is handled by a Crystal CS8425. The UDA1335H uses an 8051 derivative for housekeeping booting its code from an external EPROM and storing parameters to a 24C16 serial EEPROM. I've thought of several elegant ways to address the config issue but for now I'm just manually swapping 24C16 EEPROMs after having stored the different configs I used.

The original Opcode Sonicport/Datport driver utility disk for Windows 98 is available here.

Images both an analog config and a digital 44.1k 16 bit config available here.

Posted by cary at 11:14 PM

September 9, 2007

Bay Area Analogue Heaven Gathering

I just returned from the bay area Analogue Heaven gathering at the 21 Grand gallery in Oakland. A good time was had by all. My pictures are here:

http://www.retrosynth.com/slideshow/20070909_baah/

Additional photos by Jim Whittemore here:

http://synchro1.smugmug.com/gallery/3454091

and Jon Schatz here:

http://www.divisionbyzero.com/ahcali2007/

Posted by cary at 9:35 PM