Alps blue wiring

[ablaze 0]

Hi guys,

how should I wire up my alps blue pot?

I have a cable #1 going out of the line-out of my sound card

and cable #2 goes into the line-in of my speaker/amp.

using Mogami 2534 quad-cable.

 

I've got it like this so far:

#1 denotes cable #1 (input to the pot)

#2 denotes cable #2 (output from the pot)

L denotes pot's left channel

R denotes pot's right channel

 

                        
#1-Lchannel --> |L-in        <pot>        R-in| <--#1-Rchannel
#2-L-channel--> |L-out       <pot>       R-out| <--#2-Lchannel
#1,2-ground --> |L-ground    <pot>    R-ground| <--#1,#2 SHIELD

 

does that look right?

 

I should add that I'm basically adding a volume control to the setup, hence the pot.

[jtfoo 0]

Looks okay, remember the shaft is on your left hand side, else you'll have a anti-clockwise for vol up..

[ablaze 0]

thanks jt.

should cable #1 ground go into L-ground, and cable #2 ground go into R-ground? why does it only work when I ground them to the same ground of the pot ie. L-ground in the diagram above?

[jtfoo 0]

               Channel  Channel
               1        2  

             ===================
            | o ->in  | o ->in  |
============|         |         |
|  Shaft    | o ->out | o ->out |
============|         |         |
            | o ->Gnd | o ->Gnd |
            ====================  

Edited August 15, 2003 by jtfoo

[jtfoo 0]

should cable #1 ground go into L-ground, and cable #2 ground go into R-ground?

 

No need to be that complicated. Usually is L-Cable 1 ground and L-cable 2 ground are jointed together and connected to L-ground of the pot.

[ablaze 0]

ie. my grounding is correct for the cables' ground wires?

 

in that case, how the shield has to be grounded to a different ground?

 

sorry if I sound confused. I AM

[jtfoo 0]

Is your ground the same as shield? usually they are the same if you're using co-axial cable. If you' have an extra layer shielding, maybe just connect it to a convenient grounding point on the PCB. The pin on the Alps pot is too small and difficult to solder all the grounding and shielding together.

[ablaze 0]

no, I got a separate shield for my cable. (I have it grounded on my source end currently)

what I found is that if I don't ground the shield to the other pin (R-ground on the pot, in my first diagram), when at the minimum volume position, some sound will still leak out from the R channel.

 

so you're saying, by right, I can ground the ground of the cables,+the separate shield to the same ground pin on the pot?

[jarthel 0]

just a question:

 

since you're using a soundcard, is there any point in controlling volume using a potentiometer? Why not just use the software volume control? Potentiometer is another component that may color the sound. Also with a potentiometer especially a log carbon pot/conductive plastic, channel matching with be a concern (for me at least).

 

An Alps is good but I doubt it would compare to the built-in software volume control.

[ablaze 0]

hi jarthel, reason being my soundcard (or least the one I'm thinking of trying out) is a 2channel card. and my speakers actually have no volume control (Creative Microworks - designed by Henry Kloss ). I'll need a volume control or at least a switch if I want to listen to my headphones, to mute the speakers, which are connected to the same line-out of my soundcard.

[jtfoo 0]

no, I got a separate shield for my cable. (I have it grounded on my source end currently)

what I found is that if I don't ground the shield to the other pin (R-ground on the pot, in my first diagram), when at the minimum volume position, some sound will still leak out from the R channel.

 

so you're saying, by right, I can ground the ground of the cables,+the separate shield to the same ground pin on the pot?

Sound leaking at minimum value. My guess is your R-channel ground is not connected properly.

 

With a broken gnd circuit, it'll look like this

 

 

In
  |
  >
 <
  >
 <
  >
  |<------Out -Sound will leak at minimum setting. BAD
  |
 Break
  |
  = Ground    



In
  |
  >
 <
  >
 <
  >
  |<------Out. No sound at minimum as 'Out' is effective short to ground. GOOD
  |
  |
  = Ground

 

MEasure for continuity on the R-ground of the pot to ground of the cable.

Edited August 15, 2003 by jtfoo

[ckng 0]

hi jarthel, reason being my soundcard (or least the one I'm thinking of trying out) is a 2channel card. and my speakers actually have no volume control (Creative Microworks - designed by Henry Kloss ). I'll need a volume control or at least a switch if I want to listen to my headphones, to mute the speakers, which are connected to the same line-out of my soundcard.

I am using a MicroWorks for my PC, there is a little wired remote control. It's basically a cheap pot with 2 long wires terminated with 3.5mm stereo jacks. One end goes to sound card, one end goes to sub. Maybe you lost them?

 

But using a ALPS for that sounds cool, I might just try on mine. That volume control of mine has gotten noisy.

 

Regards

CK

[ablaze 0]

thanks jt. what I did was connect it the way I did in my first post. and everything works just fine.

I think I won't pursue this, the more I do, the more lost I get.

 

thanks for the input jt. always can count on you to save me everytime I try some DIY

[ablaze 0]

hi jarthel, reason being my soundcard (or least the one I'm thinking of trying out) is a 2channel card. and my speakers actually have no volume control (Creative Microworks - designed by Henry Kloss  ). I'll need a volume control or at least a switch if I want to listen to my headphones, to mute the speakers, which are connected to the same line-out of my soundcard.

I am using a MicroWorks for my PC, there is a little wired remote control. It's basically a cheap pot with 2 long wires terminated with 3.5mm stereo jacks. One end goes to sound card, one end goes to sub. Maybe you lost them?

 

But using a ALPS for that sounds cool, I might just try on mine. That volume control of mine has gotten noisy.

 

Regards

CK

actually yeah I got those. but its just looks so crappy I decided to replace with an alps blue and better cables. too bad cannot fit into that little box they use

[Northern Oak 0]

Ablaze, do you happen to have a multimeter? Use it to check the resistance on each channel between out and ground with the gang turned to both extreme. Check to see if you get about the same readings. It will be able to tell you that when the pot is turned to both extreme, the resistances are tracking close to each other, so you wouldn't have un-balanced channel.