Author Topic: QRV-08 PANEL MOUNT POT  (Read 4913 times)

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Offline CapRock

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QRV-08 PANEL MOUNT POT
« on: January 18, 2011, 05:09:21 PM »
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

Offline peranders

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Re: QRV-08 PANEL MOUNT POT
« Reply #1 on: January 18, 2011, 06:43:19 PM »
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
« Last Edit: January 18, 2011, 06:44:33 PM by peranders »
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Offline CapRock

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Re: QRV-08 PANEL MOUNT POT
« Reply #2 on: January 19, 2011, 05:12:31 PM »
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

Offline peranders

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Re: QRV-08 PANEL MOUNT POT
« Reply #3 on: January 19, 2011, 10:58:38 PM »
It doesn't matter if you have 10 or 100 k if the attenuator is good.
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Offline CapRock

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Re: QRV-08 PANEL MOUNT POT
« Reply #4 on: January 20, 2011, 01:20:56 AM »
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. 

Offline peranders

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Re: QRV-08 PANEL MOUNT POT
« Reply #5 on: January 20, 2011, 06:20:10 AM »
You can use regular caps or snap-in caps.
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Offline CapRock

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Re: QRV-08 PANEL MOUNT POT
« Reply #6 on: January 20, 2011, 08:33:38 PM »
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?

Offline peranders

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Re: QRV-08 PANEL MOUNT POT
« Reply #7 on: January 20, 2011, 08:54:29 PM »
Please, see my answer above, snap-in OR regular caps. Choose the type you'll like.
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