ARF VCO - No Bananas

Last night, I went ahead and performed the "bananaectomy/phonejackoplasty" operation on my ARF VCO. Sorry for the quality of the pictures. I'm not sure how to insert proper links to the larger images. Blogger seems to just want to use the thumbnail version.

The original panel was hand-drilled, hand-labeled, and fitted with banana jacks. Since this is a "free rack" module (that is, a 19" rack unit, not a FracRack or other sub-rackspace format), it's destined to get 1/4" jacks.

The conversion was both harder and easier than I was expecting - the banana plug mounting nuts were a bear to get loose until I remembered I had an appropriately sized nut driver in the garage. The wires however, were pretty easy to get loose. I wound up labeling them with masking tape so I wouldn't get confused about which wire went where.

I also performed the conversion one column at a time. Here's the view after the first column was replaced.

Grounding is always a problem with 1/4" jacks. Though they were mounted to a metal face plate, and that provides a common solid grounding point, I also decided to go ahead and wire each ground lug together. I "snaked" the ground through all the lugs, and attached a fly wire from the last one back to the PCB's ground area, approximating a star grounding configuration. I suspect this step was unnecessary, and my multimeter's continuity tester showed that the panel was already electrically connected to the module's ground line, but since my other ARF module wired all the ground lugs together, it seemed appropriate.

Here's the final back panel. After hooking everything back together, I returned the module to its home, and everything is working fine! I really do like the feel of phone jacks over bananas. It's so easy to repatch things that nothing gets in the way of sonic exploration.

The whole project took around two hours, including time for trying to find hookup wire and nut drivers. Not too bad, though now I'm out of 1/4" jacks, and future work will require actually spending some money. Alas, can't be a cheapskate forever. ;)

Here's the VCO patched up for a simple "play me a square wave mixed with a triangle wave, with vibrato added from an LFO" voice.

The one down side to this scheme is that I lose the color coding for the SYNC plugs, which are not V/Oct control voltages.