Here is the schematic diagram of the KIA6210AH stereo
amplifier (click on the picture to
Attention: The power supply must be between 12 and
14.4 Volts. The power on signal is generating by the voltage
divider (100KÙ and 88KÙ
resistors). This must be approximately 3 Volts when it is
connected with KIA6210AH chip (pin 4).
According to the
constructor company, you can ignore the two feedback 470Ù
resistors. With out them, the gain is 50dB (maximum).
According to the same source, if you use the 470Ù
feedback resistors (like I did), the gain becomes
40dB and the two input capacitors must be 3.3ìF.
Also the two feedback electrolytic capacitors must be 33ìF.
As you can see in the schematic I used 4.7ìF
and 47ìF electrolytic capacitors instead.
This is not causing any problems. However, if you like you can
change them to what the constrictor suggests.
Make sure you
solder the two 1nF capacitors (at both inputs) as close
to KIA6210AH as possible.
In the following pictures you see the amplifier connected on
a breadboard (for tests only).
Here is how I connected the chip.
You can also see that I used a large aluminum cooler.
And here is the
whole circuit, with the speakers included.
This is the circuit from
a closer look.
In this picture you see
the mute cable (the red unconnected wire at the left). When
you connect it to ground, the amplifier is muted. At normal
operation just leave it unconnected (free to air).
Alternatively connect it to the power supply (12 Volts).