7 - Using the NoSo One with 3.5mm audio input
barry (Administrator) 12-07-2015 at 03:56 AM.
Post: #1
The breadboard lets you tweak and rebuild your amp as often as you like. With a 3.5mm jack socket and a minor circuit revamp, you can plug in your MP3 player or smartphone and listen to the audio output. The kit of extra parts includes the socket, some resistors, some extra wire and a suitable cable.

Whether you have the Basic or Plus version of the NoSo One, remove components and wires until your breadboard looks like the picture below. (Keep the parts and wires safely on one side - you can rebuild the NoSo One in any form as often as you like.)

   
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barry (Administrator) 12-07-2015 at 04:10 AM.
Post: #2
Make room for the jack socket
The jack socket needs quite a bit of space on our breadboard, so we need to shuffle a few parts around. First, relocate the red battery wire to the hole next to the LED. Then move the large 330uF capacitor to the top corner of the board. Rotate it so that you can get its leads diagonally into the two holes shown. Make sure that the negative lead is plugged into the ground row (black wire).

   

Now move the short wire that connects pins 2 and 4 of the LM386 chip. Just pull it out and then reposition it one row lower, so the same pins are still connected. This makes some space for a short connecting wire, which runs from pin 2 of the LM386 to a hole 4 positions to the left. In the diagram below, I've shown the wire in pink to make it clear.

   
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barry (Administrator) 12-07-2015 at 04:41 AM.
Post: #3
Add the jack socket
Now add the jack socket. It fits right up against the pink wire and extends to the the front edge of the breadboard. The protruding 'nose' of the socket means that it can only fit one way. Push it into place so that the five pins on the underside are all gripped by the breadboard's spring contacts.

   

Add some resistors
There are three resistors, all 1k (brown-black-red colour bands) to fit. The first is easy, and to the ground row (black wire) at the far right edge of the board. Trim and fit this resistor first.

   

The next two resistors are more fiddly, because we have to trim and bend their leads so that they extend over nearby components. The first one fits over the LM386 chip. In effect, it's the same as the previous resistor, but with the leads longer so that the resistor is in the air, instead of flat against the breadboard. Here's the position, shown from two directions. As you can see, the resistor doesn't touch the LM386 at all.

   
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barry (Administrator) 12-07-2015 at 04:53 AM.
Post: #4
Final components
The third resistor is also a bit fiddly. It fits in the position shown here, plugging into the same row as the other two resistors at right side and making a connection to jack socket on the left side. (Neither end touches the pink wire, that one's just laying flat against the breadboard, out of the way of this resistor.)

Finally, add the green input capacitor. One end connects to pin 3 of the LM386 and the other connects to the group of three resistors that you've already added.

   

Your finished circuit should look like this. Check each component and wire position carefully before continuing.

   
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barry (Administrator) 12-07-2015 at 04:59 AM.
Post: #5
Using your NoSo One with audio input
The NoSo One's battery is switched on when there's a guitar cable plugged into the (now unused) guitar input, so do that first. The LED should light up as before. Now use the 3.5mm stereo jack cable to connect your MP3 player or smartphone (or laptop, etc) to the NoSo One's 3.5mm audio input. Play some music and you will hear the music through the attached speaker.

As always, the sound quality and room volume depends largely on the speaker. You will get good results from plugging into a good quality stereo or hi-fi speaker. Here's an old JBL speaker that I had left over after its twin stopped working - it's perfect for the NoSo One.

**(video to come)**
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