Quote:
Originally Posted by Citroënbender
So the "hiss" is coming in at the preamp stage?
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Yes. Look Ma, no amp input... (I've cut a couple of legs!)
Hiss is still there, but it's about 1/5th now. If I could get it down to this volume level when the inputs are connected, it would be perfectly fine.
The radio has two large chips (one is a 16 bit microcontroller - with custom programming, not sure what the other is) and three "for car radios" components:
TB2934HQ (This is the part I've cut) the 4 way amplifier chip. Those are the two rear speaker inputs, the part says 41W per channel max, 27W typical. This part connects to the speakers via the large white plug without any other components in between.
TDA7462D (the first stage input audio processor) which I'm considering pulling up the 4 output pins and connecting them to the amp (via recommended 0.22uF caps) to bypass everything in between (may lose a software equaliser, and perhaps various beeps).
HA13173H car radio power regulator. I guess I could wire up some extra capacitors on the voltage outputs first (5.0v, 3.3v, 8.0v, 2 x 8.
4v + one other output on a software switch - probably the +12v input?).
This radio may never see the inside of a car again.