how to mix sound from notebook and external sound card and get headphones output
 

Hi all,

I want to mix sounds from notebook and external sound card (guitar is connect to it) and get mixed sound on my headphones.
I want to hear mixed sound from youtube and my guitar while playing.

I am beginner in electronics and after reading a lot of threads and I'm a little bit confused :confused: what is best solution.

I need advice what device to build:
Active or passive mixer or headphone amplifier with crossfeed?

Thank you in advance.

At some point, the kind of headphones you're using is a factor. That said, I think you could use an active solution of an op amp mixer with volume control on each input. A common IC like a NE5532 may provide enough output for your 'phones.

Thanx sofaspud!

Could you please recommend some schematic of op amp mixer with NE5532?

This schematic is from the Learn about Electronics website. I took the liberty of changing their 3-input mixer into the 2-input circuit you need.
The purpose of the second op amp is to maintain the same phase as the input signal. If you use it, put a resistor of 50-100 ohms between its output and the headphone jack. If you don't use it, make R6 that 50-100 ohm resistor.
The above description is for a mono output. If you want stereo, you'll need to make 2 of these circuits, one each for left and right channels.
You'll need a small power supply also. ±12VDC would work fine and be easy to build.

I neglected to say there's a few ways to combine these signals to the headphones.
*Left, right, and guitar on both sides of headphones.
*Left side, right side, and guitar on one side.
*Left side, right side, and guitar on both sides.
Not sure which you want, but each require a slightly different circuit based on the schematic above.

Thank you for quick reply.

These two options are OK:

*Left, right, and guitar on both sides of headphones.
*Left side, right side, and guitar on both sides.

What external sound card are you using that can't do this already?

I'm using Lexicon Alpha
http://static.musiciansfriend.com/de...5507_front.jpg

but with "Monitor Mix" pot on middle postion I don't get clear sound from both channels (guitar is line in 1, headphones output from notebook is line in 2).

If I turn "Monitor Mix" pot completly to the right I only can hear well a guitar (with effect) and vice versa. If I turn pot to the left I can only hear a clear and nice sound from notebook.

In the middle position I can hear:

- guitar (clean sound of guitar)
- guitar sound with distorion or some other effect from guitar rig
- sound from notebook

and all these sounds are not clear

That's a good question; maybe there is a hardware or software solution. I don't think any card I've owned could do it, but then again I've never tried. Anyhow, here's the new schemo. Mono so nothing needs duplicated for another channel.

I'm using entry-level headphones Sennheiser HD 415 (nominal impedance 32 Ohm). I hope that will not be a problem :)