Calibration
There are sixteen trimmers on the SE330. It will be useful to have access to an oscilloscope
and a frequency counter for the calibration routine, however, it is not necessary as most
adjustments can be done with just your ears and a voltmeter.
All voltages should be measured with respect to a suitable 0V point. That is the black lead of
your meter should be connected to 0V. 0V is most easily found at the cathode of D18 – the
end that is nearest to the power header.
Set the SE330 so that the two modulation depth pots are at their minimum value.
CLK1
This sets the delay time of BBD line number 1.
If you have no scope or frequency counter then adjust CLK1 so that pin 1 of U12 is
approximately 3.30V.
If you have access to a scope or frequency counter then measure the signal at pin 6 of U6.
Adjust CLK1 so that the frequency of the square wave is approximately 75kHz.
CLK2
This sets the delay time of BBD line number 2.
If you have no scope or frequency counter then adjust CLK2 so that pin 1 of U32 is
approximately 3.30V.
If you have access to a scope or frequency counter then measure the signal at pin 6 of U17.
Adjust CLK2 so that the frequency of the square wave is approximately 75kHz.
CLK3
This sets the delay time of BBD line number 3.
If you have no scope or frequency counter then adjust CLK3 so that pin 7 of U12 is
approximately 3.30V.
If you have access to a scope or frequency counter then measure the signal at pin 6 of U26.
Adjust CLK3 so that the frequency of the square wave is approximately 75kHz.
CLK4
This sets the delay time of BBD line number 4.
If you have no scope or frequency counter then adjust CLK4 so that pin 7 of U32 is
approximately 3.30V.
If you have access to a scope or frequency counter then measure the signal at pin 6 of U35.
Adjust CLK1 so that the frequency of the square wave is approximately 75kHz.
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