Impedance adaptor

[jmth]

I'm thinking about making a impedance adaptor to connect my amp rec out to the mic input of the pc (or maybe guitar directly)
Should an op. amp without any amplification work or I need something more?

[Seljer]

Your amp's recording out is probably pretty strong already, you'll probably overdrive the little preamp built into the mic in channel. Try running it directly to the computer's line in jack.

To run the guitar directly though, you'll need some kind of buffer, the input impedance of the mic input is probably only a couple of kiloohms. The unity gain opamp buffer you mentioned would work fine. And personally, I've had more luck adding some gain and running it into line in as the mic in's preamp is horribly noisy (it's also easier to set your levels to avoid clipping).

[Bill Mountain]

I'm thinking about making a impedance adaptor to connect my amp rec out to the mic input of the pc (or maybe guitar directly)
Should an op. amp without any amplification work or I need something more?

An opamp buffer would do fine.

[EATyourGuitar]

an attenuator would also work

[jmth]

I tried to run it directly and it had no sound, just like hitting muted strings with a fingertip, and it was at a 75% of amp volume.
Ok, I will do it to connect the guitar directly (less cables...)

The circuit will be just a 3x2 cm piece with only a LM358N (8 pins, easy to find, recommendations?) op amp, fed with 2x1.5V batteries, jack female input and a jack cable out... I've made the PCB design, I can upload it in PDF.