passive level control

[Autophase]

hey guys i want to build a small box with a single gain control, that has 2 jack inputs and 2 jack outputs to control the volume from my soundcard to my preamp monitors.
I want the signal the be as unchanged as possible, hence the "Passive" in the title, and I assume this would mean it requires no external power of any kind.
I know this sounds really noob to you guys, but any advice would be greatly appreciated.

 

[rodabod]

Balanced or unbalanced?

 

[ChrioN]

I think this is covered pretty well in a bunch of threads. Do a search.

 

[Autophase]

im not entirely sure, i know the outs on my interface are balanced and unbalanced.
I think the inputs of my monitors are also both, but I use the balanced option.
So I think balanced it the way to go.

 

[ChrioN]

quotage:

 

[rob_gould]

Have a look at these :

http://www.goldpt.com/

You may find exactly what you need, or you may find inspiration to build something similar yourself...

 

[Mark Slocombe]

If you're running balanced perhaps you could mount a couple of these in a box with some XLR input/output.

http://classicapi.com/catalog/product_info.php?cPath=48&products_id=106

 

[Speedskater]

I want the signal the be as unchanged as possible, hence the "Passive" in the title,

Well maybe!
Passive Level Controls require great attention to details.
Interconnect cable lengths matter.
The input and output impedance of the associated units also matter. 

 

[Autophase]

If i bought a stereo stepped attenuator and put my own resistors in, is there a table that will help me pick the resistors to create a smooth level curve.
The output of the audio card is line level, if that helps.

 

[radiance]

If i bought a stereo stepped attenuator

http://www.groupdiy.com/index.php?topic=38236.0

is there a table that will help me pick the resistors to create a smooth level curve.

http://www.quadesl.com/attenuator.html

 

[Autophase]

is this anygood
http://cgi.ebay.co.uk/Valab-23-Step-Attenuator-Potentiometer-50K-Log-Stereo_W0QQitemZ270542938633QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3efd9da209
or is it as cheap as it appears?

 

[radiance]

is this anygood
http://cgi.ebay.co.uk/Valab-23-Step-Attenuator-Potentiometer-50K-Log-Stereo_W0QQitemZ270542938633QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3efd9da209
or is it as cheap as it appears?

Dunno, never used these. Looks like a good deal though, espacially since it comes with resistors already done. This save's you a lot of work. However, this is a 2 deck rotary. So not for balanced signals. For balanced signals you'll need a 4 decker. Also, I don't know what value (10K, 50K whatever) you will need.

 

[ChrioN]

I once had one of these: http://www.etcetera.co.uk/products/images/SMP060f.gif

The pots were 4 ganged 2.5k logs.