#voice chips

[answersonthewall]

After 17 years the sound chip in my build-a-bear died.

RIP the voice of my stuffed buddy named Peak-a-Boo.

[felixb13sonic]

Scholarship: Day 01

Tom and I began scholarship work today; the first stage of which involves working with Roland's fabled Juno-106 synthesizer.

Our first client, a collector of old synthesizers, has brought in a faulty Juno which needs to be fixed. As our teacher Terry explained, the fault - a common one - had been traced to two of the Juno's 80017A VCF/VCA modules, i.e. the synth's voice chips. These voice chips, as I discovered during background research, are prone to failure due to a resin coating which somehow disrupts the circuitry of the ICs. This coating must be removed for the module to function normally again, which can be done by bathing the voice chips in acetone for a minimum of twelve hours.

When work began today, the chips had already been desoldered, removed from the board and stripped of their coating; Tom and I had the rather simple job of (precisely) soldering the chips back into the board and testing the results. Unfortunately, time ran out before we got to the testing stage, but we did manage to finish all the soldering; this will need to go under a magnifying glass, as Terry says there are minor touch ups to be done.

Later in the day I did some research on the Juno-106, the faulty modules and the acetone bathing process. My main sources of information were Wikipedia's entry on the Juno-106, the synth's page on the Vintage Synth Explorer (a very useful database for this type of work) and this handy FAQ.

These videos detail the acetone bath process (note that in the second video a Juno HS-60 is used instead of a Juno-106; the two synths are practically identical).

Here are .pdfs of the 106's user manual and its service manual.

Listening:

The Hollies - King Midas in Reverse

Tim Rose - Maman

Pulp - F.E.E.L.I.N.G.C.A.L.L.E.D.L.O.V.E.

2Pac - Holla At Me

Blondie - Atomic