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[Help Needed] How to wire original DMG Pot. Volume Wheel

Posted: Mon Aug 22, 2016 12:38 am
by Meia
Hi all,

I want to use the original DMG Potentiometer Volume Wheel. Does anyone has a picture or guide or anything how to use it? Does it have the same connections as Wermys Potentiometer Volume Wheel he uses in the project?

Thanks for any hints, help, pictures etc.

Cheers and good luck with your projects :)

Meia

Re: [Help Needed] How to wire original DMG Pot. Volume Wheel

Posted: Mon Aug 22, 2016 1:00 am
by Fleder
Hi. Method B should work for you.
Image

Re: [Help Needed] How to wire original DMG Pot. Volume Wheel

Posted: Mon Aug 22, 2016 1:38 am
by Meia
Awesome!!

Thx alot :)

Re: [Help Needed] How to wire original DMG Pot. Volume Wheel

Posted: Tue Aug 30, 2016 1:59 pm
by fdeluxe
I did this alternative wiring for stereo headphone output (Speakers are still mono)
GBZ_VolumeWheel_2CH.jpg
GBZ_VolumeWheel_2CH.jpg (57.94 KiB) Viewed 12828 times

Re: [Help Needed] How to wire original DMG Pot. Volume Wheel

Posted: Wed Aug 31, 2016 10:21 am
by RxBrad
@fdeluxe

Reading around on the Internet, that amp doesn't appear to have common GND for the L and R output. I wonder if merging the grounds could cause problems?

This page recommends either:
  • 10 uF caps on R+ and L+, leaving R- and L- unpopulated, and using the common ground from the PWM circuit for the pot & headphone jack
  • 47uF cap and 4ohm resistor on each of L- and R- before merging them to a common ground for the pot/headphone
  • a third method using a bunch of resistors

Re: [Help Needed] How to wire original DMG Pot. Volume Wheel

Posted: Wed Aug 31, 2016 3:57 pm
by fdeluxe
@RxBrad

Yeah I am getting some pretty bad noise when I increase the volume. I gonna try out the methods you mentioned.

Edit: Okay I just desoldered the R- and L- and the noise is reduced to an acceptable level for the GBZ output.

Re: [Help Needed] How to wire original DMG Pot. Volume Wheel

Posted: Wed Aug 31, 2016 4:31 pm
by RxBrad
I just tested the first method with the two 10uF caps. Lots of hissing noises that correspond with the SD activity LED. Going to try method #2 next (waiting for components to show up from Tayda).

Re: [Help Needed] How to wire original DMG Pot. Volume Wheel

Posted: Wed Aug 31, 2016 8:15 pm
by fdeluxe
I really start questioning myself why there arent any headphone jacks with two ground pins... I mean if seperate grounds for L and R are the standard output from stereo amps how on earth would one be able to ever connect jack and amp? I know that the - pin isnt just GND but carries a signal on its own. But how does the common ground on Headphones work anyway?

Re: [Help Needed] How to wire original DMG Pot. Volume Wheel

Posted: Wed Sep 14, 2016 8:34 am
by uke
Fleder wrote:Hi. Method B should work for you.
Image
I don't understand. I'm using an adafruit jack (Same as ebays, apparently). In wermy's videos he wires the wheel to the amp, only. Why is it wired to the jack too in those diagrams? I plan on using the original wheel also.

Thanks!!

Re: [Help Needed] How to wire original DMG Pot. Volume Wheel

Posted: Thu Sep 15, 2016 12:54 am
by Fleder
uke wrote:I don't understand. I'm using an adafruit jack (Same as ebays, apparently). In wermy's videos he wires the wheel to the amp, only. Why is it wired to the jack too in those diagrams? I plan on using the original wheel also.

Thanks!!
Hi,

the pinouts for several audio jacks can be found here: http://sudomod.com/forum/viewtopic.php?f=22&t=701

Now, to your question.
The Pot should usually be wired before the amp, as some old pot wheels might not be able to handle the output the amp could send.
But i think this is not really a thing, so i found this wiring better in terms of static, noise and volume.

You could just swap it out and put the pot in front of the amp, if you want to be safe.
The first pin is the input and the third the output, i think you should be able to alter the schematics yourself, right?
Just get your input to the first pin, and then from the third to the input of your amp.
Then go from output of your amp to the pin that is wired to the green one from the pot's output.