[dogwan]

The output should be plugged into one of the inputs on the Matrix. The outputs on the Matrix are for using as a preamp and put the signal out to other gear. On the soundcard you should be using the ouputs.
 
If that's obvious I'm sorry, but based on your wording it sounds like you have the hookups wrong (backwards?)
 
Soundcard output------> Matrix input (1 or 2)------> Headphones

 

[d3xtro]

Ok now I hear it ok, but now left phone is a lot quieter than right? hearing a kind of crackling sound always as well. strange.

 

[francisdemarte]

Check your gain switches and make sure they are both set the same also make sure your jack are plugged in all the way. Crackling maybe a bad cable or they picking up interference.

 

[d3xtro]

Quote:

Check your gain switches and make sure they are both set the same also make sure your jack are plugged in all the way. Crackling maybe a bad cable or they picking up interference.

Actually there is no sound out of the left. both plugged in firmly as well. I did hear a faint tone from the left before when testing the channels in my sound cards control panel, but not now. hmm whats up? 

 

[d3xtro]

I now get sound out of both fine though when I plug it only half way into the amps jack not fully in. what the?

 

[Hughkk]

where do u buy it for 250?
 
the only place i can find which sell it is ebay at around 280

 

[dogwan]

Quote:

I now get sound out of both fine though when I plug it only half way into the amps jack not fully in. what the?

Sometimes when you pull the headphone plug out 1/2 way it bridges into mono. It's possible that is what you are experiencing. I believe that tells you that both drivers and the cable are working.
 
Now, what's causing the crackling? Have you tried plugging another device like an Ipod into the amp? Tried using a different set of RCA connectors? This will help eliminate those as the culprit.
 

 

[Hughkk]

how does this sound with hd650?

 

[Chris J]

 
Quote:

Actually there is no sound out of the left. both plugged in firmly as well. I did hear a faint tone from the left before when testing the channels in my sound cards control panel, but not now. hmm whats up? 

Hey,
Check to ensure BOTH sets of gain switches on the Matrix are set exactly the same, there is a set of two on the left and a set of two on the right on the bottom, try different gain settings, the switches might be dirty.  Try different inputs on the Matrix. You may have a bad connection on one set of inputs or input switch may be dirty, try toggling it a few times.
 

 

[Chris J]

 
Quote:

where do u buy it for 250?
 
the only place i can find which sell it is ebay at around 280

I bought my Matrix for 250 USD plus shipping from coolfungadget.
Try googling "coolfungadget".  Should direct you to a site called "TamAudio "
His shipping is very fast too. 
You can also buy Op Amp upgrades from them for the Matrix M Stage.
 
 

 

[Hughkk]

why u can choose between 2 voltage, what diference are there?
 
and is this http://www.ebay.co.uk/itm/Matrix-m-stage-Headphone-Amp-/350332764004 the same thing?

 

[francisdemarte]

Different countries use different power cords and have different voltages coming from the wall socket.

 

[Hughkk]

so if i travel through different countries, i cannot use the same amp?

 

[francisdemarte]

Depends on the country, you can if they have the same voltage as your home country. You many need a plug adapter, otherwise you will need a voltage adapter also. 
 
See this: http://www.kropla.com/electric2.htm
 

 

[EraserXIV]

has anyone tried replacing the volume knob on the m-stage? it seems like it'd be a pretty easy swap out and would be a great upgrade on the stock one.