Audio controller, more than one input source.
Just a post to let you guys know what ive been working on. Ive got some CD4066 14pin DIN chips, (quad bilateral switch) on a vero board and hooked it up to my inputs and outputs to the amp. So far ive only tried it on the test bench and it seems to work. More testing later to see if it doesnt affect the sound quality too much. If the decrease in sound quality is noticable, ill ditch it.
This all started when i finished my incar PC and couldnt use my car's factory HU and on steering wheel radio and volume controls. Very frustrating in city traffic!:P
Ive got the PC in the front, USB sound card in the back, next to a 5 channel amp (5.1) The usb sound card feeds the front and rear pair of speakers, and the sub to the amp. The wiring for the speakers from the amp have taken over from the car's existing speaker wiring. I have connected a speaker to RCA converter to the car's old speaker wiring, to pick up the signal from the car's HU, and that then goes to this circiut.
So this circiut interupts the 5.1 channels from teh sound card to the amp and switches over to the HU signal.
I've found so far, that even tho the 4066 is not intended for audio use, it works just fine. But of course more work is needed to really see if there is any sound quality loss.
I hope this drawing isnt too confusing for you guys, it took me a while to do it...without mistakes...i hope :confused:
anyway, all it basically does, it connect the 5.1 in to the 5.1 chans out when you connect the audigy sound card control wire on (to positive power +12), 5 switches come on and route the signals
OR, when you leave that wire off, and connect power control to the OTHER control wire, then another set of 5 switches turns on and connects the two inputs to the five outputs. I hope that makes sense.
The 10Kohm resistors on the signal control wires are just to stop the signal floating above ground when they are not ON. If these were not there then they would not turn off straight away, and cause two signals to be on at once.
I would suggest connecting both control wires to a "or" switch, (double position, single throw switch) to positive, to make sure only one is on and never both.