In Part 1 we looked at recording skype conversations using software. Now we’ll look at an alternative hardware setup. As mentioned previously this is the more fun way for me. As a former electronics engineer working in the audio broadcast industry this ticks a lot of geeky boxes for me and takes me back to my radio roots. Ahh, enough of the misty-eyed stuff :-)

This setup might be particularity useful if you or your learners are making a radio style podcast with local guests and remote guests calling in. You could pick up a budget mixer and mic for under £100.

And the good news is, it’s actually quite straight-forward to set up. The main component of this setup is the audio mixer. It doesn’t really matter what type it is as long as it has an AUX bus. That’s the important bit. It allows us to set up a MIX-MINUS or Clean Feed. More on that shortly.

My equipment list

Tapco 6306 6-channel mixer
Audio Technica AT822 Stereo unbalanced Mic
Mac Mini or Samsung NC10 netbook
Yamaha Pocketrak CX Audio Recorder
A set of headphones

My skype hardware setup

The Setup

I’ve drawn a quick, simplified block diagram of the mixer below, omitting level, gain and eq controls. The diagram shows where the connections go to and from on your Mac or PC and the essential controls to set up a MIX-MINUS feed.

[Larger image of block diagram]

1. Attach your Mic to your MIC Channel. In this case Channel 1.  Set the Pan control to the Left. Turn the AUX 1 Volume up to an appropriate level.

2. From your Mac or PC take the headphone output and link it into a Stereo Line channel. Channel 3+4 in this case. Turn the Balance to the Right and make sure AUX1 Volume is at 0.

3. Take the feed from the AUX Send output of the mixer and put that into the Line-in of your Mac or PC. If your PC doesn’t have a Line-in, turn the AUX 1 volume down very low on the Mic Channel 1 and connect the output of AUX Send to the Mic Input on of your PC. Note if the levels are still too high you may need to add an attenuator to reduce the signal level. If you’re feeling adventurous you could make your own passive one from a couple of resistors.

4. Take the Left and Right Main outputs of the mixer and feed that into the line-in of your audio recording device. In this case a Yamaha Pocketrak CX.

5. Attach a set of headphones to the headphone output of the mixer. You’ll hear your voice in the left ear and the remote caller’s voice in your right ear.

6. Now your ready to fire up skype and set the recording levels. I usually do this by calling up the skype test call lady (echo 123). The meters on the mixer should bob about the 0 mark and avoid going into the amber and red regions or your recording will be distorted.

7. With levels set you’re ready to make your skype call and hit record on your audio recording device. Here, a Yamaha Pocketrak CX.

8. Once you’ve transferred your audio from your audio recorder you can now edit your it. I’ve detailed that in Part 1 Section 2. You don’t need to do the first step as it is already a stereo track.

In summary what we have done is to send your Mic feed to the left output channel and the remote user’s voice to the right output channel. We’ve made use of the AUX bus to send that output to the remote user minus their own voice hence the term MIX-MINUS. We achieved this by turning the AUX 1 Volume of Mic Channel 1 up and setting the AUX 1 volume of the Stereo Channel 3+4 (the remote user’s voice) to 0.

The actual mixer settings below.

Notes

1. In the setup photo I’ve got the mac mini and mic quite close together. That’s just for demonstration. The mac mini is normally as far away as possible from the mic so that it does not pick up the fan noise.

2. I’m using a stereo mic here. My first choice would be a mono mic as we don’t need stereo.

3. I discovered after doing a test recording with Craig that the Yamaha Pocketrak CX, in line-in mode only records in MP3 at 192kbps. When I’m recording again I’ll use my M-audio Microtrack which records in full uncompressed audio.

4. In the close-up photo of the mixer setup I’m using the Tape Output to send to the Yamaha Pocketrak CX to record rather than the main L & R outputs. Purely because I couldn’t find my 1/4in jack leads :-)

You can hear a sample recording with this setup here. I’m joined by Craig Mill, our eLearning Advisor for Accessibility and Inclusion to talk about MyStudyBar – a floating toolbar to aid learners with literacy related difficulties such as dyslexia.

And finally, If you’ve got any questions or queries about this setup please don’t hesitate to get in touch :-)