BR VCF 114 V1d
3
Assembly Instructions
The Band Reject (notch) VCF module has no particular requirements not already covered in
the ‘General Guidance on a M²Synth Module Assembly’ booklet included with this kit.
Calibration
1.
Power up module and allow to ‘warm up’ for 1
0 minutes
2.
Connect a 100Hz sine wave @ 10V Pk-Pk to Signal input 1. Bandwidth (resonance) to
0%, Signal 1 Level to 100%.
3.
Adjust cut-off until output is at a maximum level using an oscilloscope (there are two
peaks, either one is fine.
4.
Using Pr1, adjust until output is 10V Pk-Pk
5.
Apply a CV of 0V to the COF
‘
CV In
’
input
6.
Adjust cut-off until output is at a minimum level (finding notch centre).
7.
Apply a CV of 4V to the COF CV In input (should move notch centre up 4 octaves)
8.
Change the input frequency until the output is at a minimum level (finding new
notch centre). The applied frequency should be 1.6kHz. If not, continue to step 9.
9.
Use Pr2 to calibrate at 1.6kHz (see note below)
10.
Change the input frequency back to 100Hz
11.
Repeat from step 5 until 4V gives a notch centre of 1.6kHz
Note: If the frequency is flat (<1.6kHz), use Pr2 and make the frequency lower (flatter), if
above target frequency, use the trimmer to make the frequency even higher, this can be
counter-intuitive. You will soon get the feel of how much to increase or decrease the
frequency by.
Specification
•
Supply v/-12Vdc
•
Supply c13mA / -16mA
•
Waveform /-5V
•
Frequency range: 20Hz to 15kHz without any CV applied
•
Main PCB dimensions 43.5x130mm
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