i WOULD LIKE TO USE AN EXTERNAL PANEL MOUNT POT FOR THE QRV-08. IN KNOW PER RECOMMENDS 10K LOG BUT DOES IT NEED TO BE DUAL GANG? ALSO IF USING AN EXTERNAL POT DO I STILL NEED TO USE THE PC MOUNT CERMET POTS P1 AND P2? HOW AND WHERE WILL I CONNECT THE EXTERNAL POT TO THE CIRCUIT BOARD. IM ALMOST FINISHED POPULATING THE BOARD AND WANT TO KNOW WHAT TO BUY SO I CAN FINISH IT UP, THANKS...CAP
Please switch off CAPS LOCK!
Sorry, for my late answer. I had your email and was going to answer you today.
Dual gang is practical but if you can cope with two separate pots, that's up to you.
P1 and P2 is for input bias current compensation. Use good quality trimpots.
How to connect external pot?
Wiper => input
CCW side => ground
CW side => to your signal source
CCW side => ground
http://sound.westhost.com/project01.htm
http://en.wikipedia.org/wiki/Potentiometer
http://en.wikipedia.org/wiki/Voltage_divider
http://knol.google.com/k/electronic-circuits-design-for-beginners-chapter-6#
http://www.sengpielaudio.com/calculator-voltagedivider.htm
sorry for the caps lock, wont happen again. I decided to go with a stereo stepped attenuator instead of a pot. if I use a 10k attenuator will it be enough to completely kill volume when rolled all the way counter clockwise or will I need a higher value? thanks...Chris
It doesn't matter if you have 10 or 100 k if the attenuator is good.
Ok I do have one question about a few caps on the board itself. I see that G29, G30, C29, and C30 are actually located inside of the footprint for G27, G28, C27, and C28, how do you go about mounting both in that footprint? Looking at the picture of your competed circuit board on the QRV-08 page I don't see G29, G30, C29, C30. Sorry for all the questions I just want to do it right the first time, thanks again.
You can use regular caps or snap-in caps.
I am using snap in caps for G27, G28, C27, C28. But they cover up the solder pads for G29, G30, C29, C30. Am i supposed to mount G29, G30, C29, C30 from the bottom of the board? I just dont see how it is possible to mount 29 and 30 once the snap in caps are in place?
Please, see my answer above, snap-in OR regular caps. Choose the type you'll like.