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Mike: For the CS-80, when referencing the Adjustment Procedure?document, below is what I have learned about the typos and inaccuracies on the filter and vca adjustment docs and how I do it. VCF - Complete Alignment - Page 11 ?Make sure to do the sustain level and attack adjustment procedures first. When doing the?adjustment, I use two trimmers at the same time and adjust the peak and gain pots simultaneously. Makes setting the?High Pass filter quick and easy. If you can't achieve the correct voltage settings (sometimes you can ALMOST get there, argh) then you have a bad chip. Good chips will easily hit the intended target level every time. Item 1.
The CP3 terminal reference is incorrect?and should be CP2. I use CP7 however which is electrically the same thing; it's just easier to get at the way I do it. The 4.3 Vp-p value is incorrect and is the zero-to-peak value. The correct value is double that and should be 8.6 V peak-to-peak to match the pictorial representation. Item 2.??The terminal reference of CP3 is incorrect and should be CP8. The 2.2 Vp-p value in the pictorial is correct. VCA - Page 15 Make sure you have a good ground reference for the scope on the card itself. If using a rack mounting ear, make sure the screw is good and tight (which should be done anyway). Item 2. VCA #2 Gain - As shown, but set both the BRILLIANCE and RESONANCE paddles on the main panel to the full forward (the low) position to achieve the correct wave shape. Item 4. Output Terminal - Rather than using a scope for adjusting the output VCA to 80,mVp-p,?use a good DMM and set it to dBm. Adjust the trimmer to a 28.3 mV RMS value. Much easier to do and more consistent between voices. Also, lately I've been replacing the voice card 2SC458 output transistor with KSC1815 parts as I've seen several go bad. Drop-in replacement with a lower noise figure. Yamaha went to the 1815's for the CS-70M cards, fwiw.? Scott Rodriguez 11/11/24 On Sun, Nov 10, 2024 at 11:40?PM mborish_2000 via <mborish_2000=[email protected]> wrote:
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