New Accessories update: IR Programming Line, a 5P connector wire with IR receiver & Red LED indicator, and a 2.54mm-pitch Jumper, for user who are not doing IR battle, but just need to change TK20/22 settings.
Q: I accidentally shorted speaker wire and now had barely any sound, everything still works but hardly any sound.
A: A FB might be damaged because of over current, please remove it and short its two pads by solder or wire.
Q: How to interface TK22 board to external amplifier
A: This picture shows the pin assignment of external amplifier in this example, Battery + & Battery - are power input pin, SIN+ and - is for audio signal input, SPK+ and - is speaker port.
First to disconnect black wire from HL Volume control board and isolate it with tape, wire a 2-P, 2.54mm pitch connector wire to Volume control board as shown below.
Then to power amplifier by battery or additional 11.4~12V battery pack, normally, higher the power voltage, higher the max. output power to speaker, just make sure ground of TK board & additional battery pack are connected firmly. In this case, we just get power from TK22 bottom side.
Finally, connect power form TK22 to Battery+ & Battery - pin, connect 2-P, 2.54mm pitch connector wire SIG+ and SIG-,and then connect sparker to SPK+ and SPK- pin.