EMIC 2 Question

megaionstorm

Is it possible to connect the EMIC2 sound output and the SIDCOG sound output in the following way ?
Without geting problems ?

Target output is is something like this:
http://i.ebayimg.com/t/Typhoon-PC-Lautsprecher-Stereo-2-0-/00/s/MTYwMFgxMjAw/$T2eC16hHJG!E9nm3sBltBQOhUrdKZw~~60_35.JPG

megaionstorm

I have found the solution, it's a audio mixer circuit:
http://www.circuit-finder.com/categories/audio/audio-mixer/115/fet-audio-mixer

R1 and R3 in the audio mixer circuit can be replaced with DS1803-10 (digital poti 10kOhm).
Or two PT2257 2 channels digital volume controller.
http://www.princeton.com.tw/Portals/0/Product/PT2257.pdf

9V replaced with 3,3V.

W9GFO

It looks like the mixing of the two channels is done before it gets to the FET. Can the same circuit (sans the FET) be use to mix in an Emic to the S2's audio amp?

Mike Green

Yes, the actual mixing is done before the signal gets to the FET which is used to make up the losses in the mixing portion and to isolate the output from the inputs. If you leave out the FET, the S2's audio amp will have to make up the loss and that will result in a loss of volume.

W9GFO

Thanks Mike, makes perfect sense.

The S2 is more than loud enough for me so a decrease in volume is a feature, as long as it is not too much of a decrease.