[mrpablo]

I have wired up a 3.5mm socket to a log pot, which is then connected to my TA2024 via a JST plug.

Using this http://www.accusafe.nl/wp-content/uploads/2012/04/logaritmische_stereo_potmeter_ta2024.png diagram, I connected the wires up.

After powering up the amp and connecting my phone with audio cable, I noticed the volume isn't being effected until the pot has been turn over half way.

Also, with the volume turned down, I can hear audio.

Now, I've seen a few different diagrams with different wiring instructions for stereo log pots.

What's the correct way?

Why would my log pot be behaving in such a way?

 

[Mr Rick]

I have wired up a 3.5mm socket to a log pot, which is then connected to my TA2024 via a JST plug.

Using this http://www.accusafe.nl/wp-content/uploads/2012/04/logaritmische_stereo_potmeter_ta2024.png diagram, I connected the wires up.

After powering up the amp and connecting my phone with audio cable, I noticed the volume isn't being effected until the pot has been turn over half way.

Also, with the volume turned down, I can hear audio.

Now, I've seen a few different diagrams with different wiring instructions for stereo log pots.

What's the correct way?

Why would my log pot be behaving in such a way?

Which taper are you using??
 
http://www.resistorguide.com/potentiometer-taper/

 

[mrpablo]

Which taper are you using??

http://www.resistorguide.com/potentiometer-taper/

It's a 100k stereo logarithmic potentiometer.

 

[DingoSmuggler]

Take a photo of your wiring.
What model pot is it? Does the value have a letter suffix such as 'A', 'B; or 'C', etc?

 

[Mr Rick]

It's a 100k stereo logarithmic potentiometer.

That is not what I asked. There is a difference.

 

[mrpablo]

That is not what I asked. There is a difference.

How do I know what the taper is?

Here is the product page

http://www.technobotsonline.com/stereo-16mm-100k-log-potentiometer-pcb-mounting.html

Edit - I read the article you linked, and I was right, it's a logarithmic (log) taper.

 

[mrpablo]

Take a photo of your wiring.
What model pot is it? Does the value have a letter suffix such as 'A', 'B; or 'C', etc?

No labels on the part.

This is the pot I bought

http://www.technobotsonline.com/stereo-16mm-100k-log-potentiometer-pcb-mounting.html

I'll get a photo, but it is wired up the same as the diagram. My first soldering work. Does it matter if I have a few millimetres of bare wire showing? (by the terminals)

 

[tomb]

 

Take a photo of your wiring.
What model pot is it? Does the value have a letter suffix such as 'A', 'B; or 'C', etc?

No labels on the part.

This is the pot I bought

http://www.technobotsonline.com/stereo-16mm-100k-log-potentiometer-pcb-mounting.html

I'll get a photo, but it is wired up the same as the diagram. My first soldering work. Does it matter if I have a few millimetres of bare wire showing? (by the terminals)

Not unless the bare wire shorts.

 

[Mr Rick]

How do I know what the taper is?

Here is the product page

http://www.technobotsonline.com/stereo-16mm-100k-log-potentiometer-pcb-mounting.html

Edit - I read the article you linked, and I was right, it's a logarithmic (log) taper.

All potentiometers are not created equal.  ( Obviously ) You need to use something like this.  Probably in the range of 20 to 50K Ohms.
 
 
http://www.alps.com/prod/info/E/HTML/Potentiometer/RotaryPotentiometers/RK12L12/RK12L12_list.html

 

[mrpablo]

All potentiometers are not created equal.  ( Obviously ) You need to use something like this.  Probably in the range of 20 to 50K Ohms.


http://www.alps.com/prod/info/E/HTML/Potentiometer/RotaryPotentiometers/RK12L12/RK12L12_list.html

The product is advertised as an audio potentiometer. Is it totally useless? It's rated 100k ohms. Is that bad? Could that cause the weird volume control?

 

[mrpablo]

Not unless the bare wire shorts.

No shorts.

The ground is hooked up so both ground wires are connected to both ground pins (assuming the ground pins match those in the diagram)

 

[DingoSmuggler]

What is the input impedance of your amp? It's probably lower than the value of the pot (maybe 10k or 20k) which is going to completely mess with the attenuation slope of the pot. If that's the case you'll need to use a buffer between the pot and amp (opamp stage set to unity gain, etc)

 

[mrpablo]

What is the input impedance of your amp? It's probably lower than the value of the pot (maybe 10k or 20k) which is going to completely mess with the attenuation slope of the pot. If that's the case you'll need to use a buffer between the pot and amp (opamp stage set to unity gain, etc)

I honestly don't know.

This is the amp

http://m.ebay.co.uk/itm/like/271630565083?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&chn=ps&device=m&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108