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Subject: FW: [vintagesynthrepair] oscillator calibration (general)

From: "Verschut, Ricardo" <ricardo.verschut@...>
Date: 2002-03-18

-----Original Message-----
From: Tom Moravansky [mailto:tom@...]
Sent: Monday, March 18, 2002 4:09 PM
Subject: [vintagesynthrepair] oscillator calibration (general)

Normally I calibrate a synth using my Boss TU-12H tuner which works
over a wide range and is very portable. However, this weekend I
was calibrating a Jupiter-8 and discovered something. After going through
it with the tuner, I powered it up and started playing some widely spaced
chords to hear the oscillator interaction. The beating was very unpleasant.

I decided to use my scope and tune by the Lissijous (sp?) method. I
created a 220, 440, 880, and 1760 sine waves in Cool Edit and ran the
output into one scope trace and the synth output into the other.

The end result was that I tuned the synth faster and it sounded better
using that method. Since the JP-8 is not necessarily the most precise
instrument across all the octaves, there was still some beating, but it
was more 'musical' sounding. Unless I started replacing components, I
don't think I can eliminate all beating across 16 VCOs across 8 octaves.

What do you guys use for tuning? Anyone using a strobe tuner? How does
that compare for 'real world' sound and speed?

Tom Moravansky tom@...

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