I think I know the problem. The
schematic shows the Initial Gain pot going to +15 volts and the
resistor on the PC board is 100K. The CV input resistor is also
100K, which is for a sensitivity of full gain at +5V. I would
have to look, but I think for my build I substituted a 270K or
300K resistor for the 100K to the Initial Gain pot to give it the
same sensitivity as the CV input. With the 100K you're going to
be reaching unity gain at about 1/3 rotation of the pot. And
beyond half way you'll be maxed out.
Richard Brewster
http://pugix.com
Richard Brewster
http://pugix.com
On 2/8/15 7:57 AM, ukukey@... [cgs_synth] wrote:
Hi Ken and thanks for your help.
I have build a MOTM kit provided by Bridechamber where the optional initial gain pot comes standard.
The gain control works from range 0 to 5 but from 5 to 10 it does not change the sound.
I am not quite sure if I got the calibration right.
I need to set all pots to 0 except input ( set to 1 or 2, not 10) and adjust the trimmer until no sound is coming out, right ?
About the light hum issue, I will use shielded cables and I will let you know about how it goes.
many thanks