Category Archives: construction

The design and building process of io, and documentation of io’s construction.

source code 07-03-2004

By Han-earl Park | Published: October 27, 2008

For the record: source code for io 0.0.1 beta (rev. July 3rd 2004) [91kB zip file] and supporting components [198kB zip file]. Note that I have not differentiated components used by io and those that are not; I have included every file from the MyTools folder. Significant revisions since io 0.0.1 beta as detailed below. [...]

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source code: io 0.0.1 beta

By Han-earl Park | Published: October 26, 2008

For the record: source code for io 0.0.1 beta [68kB zip file]. Note that this is only the io 0.0.1 beta specific files, I haven not included the auxiliary code in this archive. \ io \ \ load_io \ directory assignment and load file for io. \ \ see the file io_top for more information. [...]

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rack wiring: 8-pin mini DIN angst

By Han-earl Park | Published: October 22, 2008

Almost completed the wiring of the rack (except the patch panel foot switch connectors which I am leaving for the moment). No problem with the XLR connectors, quarter inch phones, MIDI cables, barrel connectors… then I hit a major snag with the 8-pin mini DIN panel socket for the Mac serial connector. Too small, too [...]

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rack: loaded and powered up

By Han-earl Park | Published: October 21, 2008

Here’s the test of the power supply and the power inlet of the patch panel.

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enclosure and power supply (intermediate version)

By Han-earl Park | Published: October 18, 2008

Here’s photos of the intermediate version of the power supply in its enclosure. The front of the unit is at the top of the image, and the back is at the bottom. You’re also looking up at the the unit in these photos. Power switch and LED indicators are at the top left of the [...]

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power supply (early version)

By Han-earl Park | Published: October 12, 2008

The power supply has to provide, at a minimum, 0.7A @ +12V for the VL70m (power consumption measured at 0.6A @ 13.1V), and 1.3A @ +9V for the pitch-to-MIDI converters (GI-10: 0.26A @ 10.2V; GI-20: 0.8A @ 11.3V). Eventually, it will also provide bipolar power for the pre-amplifier (±12V or ±15V likely created using a [...]

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pre-amp outline

By Han-earl Park | Published: October 3, 2008

The old version of io connected the output of the synthesizer directly to the amplifier. [see: figure] This wasn’t too much of a problem since, though unbalanced, the signal was low-impedance, line-level. There were, however, a couple of less desirable aspects to this. One was that the drivers (the woofer and the tweeter) would not [...]

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enclosures: patch panel

By Han-earl Park | Published: September 19, 2008

One of the, again, less glamorous, but practical elements of io 0.0.1 beta++ is the patch panel. The panel holds the connectors that need to be accessed frequently (with the exception of the audio inputs to the pitch-to-MIDI converters since they already reside on the front panels). The connectors are, from left to right, IEC [...]

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enclosures: pre-amp and power supply panels (physical artifacts)

By Han-earl Park | Published: September 18, 2008

As an update to the previous post, here’re photos of the machined and loaded panels. The front panel holds, from left to right, the power switch, 4 LED indicators (+15V, +12V, -12V and +9V), two filter bypass switches and two output level pots. The rear panel holds, from left to right, stereo audio inputs (unbalanced), [...]

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enclosures: pre-amp and power supply panels

By Han-earl Park | Published: September 16, 2008

One handy box that forms a crucial (if unglamorous) part of io 0.0.1 beta++ contains the audio preamp (basically, a couple of filters, signal amplifiers and a balanced line driver) and power supply/distribution components (9V, ±12V). I don’t have a name for this box yet, but here are the layouts for the front and rear [...]

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