Contour Enthusiasts Group Archives Forums Modifications Audio Info on stock "Premium" radio output

OK, I finally got around to testing the output of my factory "Premium" cassette deck.
The signal from the deck to the external amplifier is a LOW level signal. In other words, line level.

I checked it by connecting the output directly to a factory speaker and I got very, very low volume out of it. I had suspected this was the case from looking at schematics of the factory sound system. It shows two different connections for the deck depending upon whether or not the external amp was present.

I hope this clears up a lot of questions for people.

-Wes
98 SE Sport

If you went through all the trouble why did you not use a volt meter and a all bit (0dB) sine wave. Just run the the sine waave at max volume and read your voltage out with a meter.

Line level signals are like 2 mV to 8 v for a Car Audio Head unit. Normally anything over 4 volts is a modified HU.

8 V to 16 V out the HU is speaker level outputs. What you are reading are to outputs of a bipolar amp not a simple opamp device.

Just because it plays your speakers low does not mean it is a low level. It may just mean it is a WEAK amp in the HU and it can't push enough current for the volt it has given speaaker impedience and flux load.

That is, no power for the load, not a low level signal.

What you suggest would work, but it would be like killing a butterfly with a sledge hammer. I could have dragged out my HP scope and frequency generator and did the same thing with a lot more accuracy, but why?
The fact that the factory deck could not drive the original factory speakers tells me it's a low level output. When I say it plays low, I mean LOW like in barely audiable. It sounds the same as when I connected my home stereo pre-amp directly to speakers rather than through a power amp (did that once as a test). Besides that, I opened the Ford amp and looked inside. It looks like there is an unused provision to connect a high level input in case Ford decided to do so.
I appreciate your insight though.

-Wes
98 SE Sport