Need a help to build a VOIP phone recorder

[puta]

I need to build a phone recorder for my VOIP phone.
I thought of picking the signals from the handset is easier -Pick the mic and ear piece signal and send it to a recorder.
But do not know how build a circuit to pick the sinals / mix them to a single output to a recorder.
 
Can someone please give me a head start, or point me to a right direction or link to a design please.

[enzine]

Have you the schematic of phone?

In this case it is easier to help you.

[puta]

It is Cisco 7942 voip phone.

I found a link to a similar device for sale:
http://cpc.farnell.com/retell/156/telephone-recording-connector/dp/TE04235?in_merch=Products From This Range

and Youtube:
http://www.youtube.com/watch?v=Te15wy_N3OQ

[pickit2]

VOIP allows you to use your soundcard as well as phone, for hands free, so why not use one of the many recorders, like cooledit.

[puta]

Thank you Pickit2. I have to use it without a pc (no soft phone or cupc client).

[enzine]

Try this circuit.
The differential input configurations (U1B and U1B) allows to avoid disturbing of telephone circuits,.
U2A is a simple summing circuit with variables gain (RV1).
Choose Ra and RB to balance the gains of the two inputs (Speaker and microphone)

[enzine]

Sorry...
I forgot to add a capacitor of 1uF connected in series with each input and another in series at the output
to block any DC component present in the signal.