CS-80 Calibration Part 11: EXP Curcuits and Output Amplifier

The final page has been reached. I got really lazy here, every step took me forever because I just didn't want to do any more adjusting. But of course the last steps gave me further obstacles.

The PRA board has to be taken out one more time to adjust the final steps.

EXP Circuits

Here it is again important to have proper VCAL levels. Mine were a little off on some M-boards, hence some notes had a slightly different amplitude which will show here. I went back and redid the VCA level adjustments. I also selected one that was in the same Vpp level as most notes and used that one for adjusting both EXP circuits steps.

While the EXP WAH Curcuit went without trouble I got puzzled with the EXP Circuit Part. They used a lot of "ors", when they actually mean "first this and then that". If you do this step, just don't forget to move the CH lever according to what terminal you want to measure. It was also a little puzzling that I got reading of both channels on both terminals. So it took me a moment longer to finish it.

Output Amplifier

For this step a output cable with a 10KΩ resistor is required.

Output jack with 10kΩ
resistor

Once again I was not able to reach the levels written in the adjustment procedure. To make things more easy and because I finally wanted to get over with the calibration I just connected one of the outputs to my scope, played a single note and measured the original Vpp level and just applied that value to the other outputs, done and case closed... literally.

Continue to Part 12: Done Done Done