Inside the nanoo

I mentioned in another Blog that the nanoo was cramped and hard to work on. This image says it all. Also from the angle you can see the business end of the nanoo. The speaker terminals are are gold plated but inexpensive. And you can see the Rs232 male connector on the back. I use two of the pins to carry common ground in and two others for + and - volts. These chips use a dual supply. Notice how the chips are hard up against the case sides. You must have silicon insulation from the case.

Mini-pots were used and the cct. brd. had to be cut to get them to in. I like to use heavy copper wire for connection to the speaker terminals, you can see that here. As with this style of chip amp only three resistors are required. These I pass in through the same holes as the chip pins on the cct. brd. The signal path including the chip and speaker terminal connections is very short. The pure silver wire on the inputs is covered with a thin spaghetti. Two large bolts come through the centre of the brd. with spacers and with the secured chips hold the internals very securely.

As I have stated in the other Blog entry I wanted the nanoo to be small. I wouldn't attempt this for your first project. But have a go at chip amps in a larger case before attempting something so compact. In other Blogs I will be describing how I make my "engines". Spice engines are designed for mid-range finesse using small (2000uf) low ESR line caps. Columbia engines are designed for big bass, rock music style and employ 10,000uf line caps. I keep the PS the same for all and use only 4.7uf polies and UF diodes to provide the dual voltage. Lookout for the PS Blog next.