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x0x:vcftesting [2007/12/03 05:12]
x0x:vcftesting [2016/01/28 18:05]
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-===== Testing and Calibrating the VCF ===== 
-==== Testing ==== 
-  - Re-attach the power supply (with J4) 
-  - Apply 3volts to R90 (either with 2 AA batteries or a benchtop supply) 
-  - Probe the resonance pot with either a cheap pair of headphones or your oscilloscope. ​ With the cutoff all the way anti-clockwise,​ you should see mostly a sinewave. ​ If you're probing with headphones, you should hear a low, soft tone.  When you turn the cutoff up, you should see a waveform similar to the one you have selected on the VCO.  Using headphones you should hear a lot of higher overtones to the sound, and it might be buzzier and more '​acidic'​. 
-==== Calibrating ==== 
-According to the [[TB-303]] service manual, the resonance frequency should be at 500Hz. 
-  - Set the waveform to saw 
-  - Set Cutoff to 50% 
-  - Set Resonance to 100% 
-  - Apply 3V DC to the VCO (or press the lower C key if your sequencer is done) 
-  - Ajust TM3 so that the resonance frequency is 500Hz 
/home/ladyada/public_html/wiki/data/pages/x0x/vcftesting.txt · Last modified: 2016/01/28 18:05 (external edit)