Specification

[ashlar]

Happy Thanksgiving to everyone.

I have a question.

It has to do with "Maximum Pre-Output Voltage 2 V/10 k ohms" taken from Alpine owner's manual.

My question has to do with the 10k Ohms above. What does it mean?

[Perry Babin]

It means that the head unit can produce 2 volts of output into a 10k ohm load.

[ashlar]

So, if I were to connect it to a 20k Ohm source, what should I get?

[Perry Babin]

You would probably get the same maximum voltage.

Unless the voltage/signal source has an infinitely low output impedance and an infinitely high current output capacity, it should give the load resistance/impedance for the rated output voltage.

10k ohms is a fairly standard input impedance for amplifiers. The output impedance is probably ~100 ohms. If you tried to drive a 600 ohm load, the maximum output voltage would likely be lower (and the distortion level may be higher). For the input impedance of most amps, the head unit will be able to produce 2v.

[ashlar]

Autosound2000 Labs did a test of an Alpine CDA-7875 a few years ago and it had an output impedance of 337 Ohms.

Is it reasonable to assume that Alpine's bottom of the line CDE cd player would have a higher source impedance?

[Perry Babin]

Looking at the schematic for the CDE-9827, it appears that the output impedance would be approximately the same as the CDA-7875. There are 2 resistors after the buffer op-amps (100 ohms and 220 ohms in series).

[ashlar]

Thanks a lot Perry. You have been most helpful.