04 Connecting amplifier to computer

In the previous post, we connected the turntable to the amplifier (in my case, a boombox). Now we connect the amplifier to the computer, again using the standard audio cables, but with a slight modification, as the computer input socket is a single one carrying both the channels. So the connector cable has two prongs on the boom-box audio out end like this (the left side pair, the left and right channels are colour coded by a ring of colour, this being a more sophisticated, up-to-date 24-carat gold-plated version).

On the computer end, the sockets are coded pink for line-in, green for ear-phones or speaker audio out, and mine has a blue one which was used to connect a woofer.

The connector ends of the cable are as shown below; at the boom-box end, the usual red and white RCA standard prongs (jacks); the yellow third prong is for video signal, and not used here, and mark the gold coatings!

And at the computer end, both channels are fused into one black-coloured jack with a single prong that has two segments (the yellow prong is again for video).

The black jack (my packaging calls it a 3.5mm stereo male jack, and it happens to be grey with a blue band as befits a 24k gold thing, not black!) is then pushed into the pink socket on the computer as shown here (the green jack next to it is for the computer’s speakers).

Now the computer can receive the audio stereo input, and if you have also opened the Audacity package and started recording, you will see the sound-waves depicted in the following classical fashion (which is why the audio files have a .wav extension!).

You can have a closer look at this screen, which will be explained in the next post, but meanwhile here’s a picture of the whole set-up. One feature about my experience in getting this set up was the realisation that my laptop’s line-in (mic in) socket doesn’t seem to be working, so I have been forced to use the desk-top. The boombox also works with tapes, which is a relief, as a bigger music system I used earlier was resulting in a lot of clipping of the sound waves (apparently some hardware problem, in either the music system or the laptop). Another point is that an older turntable (a Garrard) apparently gives such a weak output that it’s unusable. Perhaps the current turntable has a certain amount of pre-amplification built in; I am not very sure.

Here’s the whole set-up.  And yes, the Violin Concerto is absolutely the first to get the treatment!