testing cd player output impedance

Does anyone know how to properly test the output impedance of a cd player ,I have a sony dvp-9000es dvd/cd player and need the info to make a passive preamp
Is it not in the User's Manual? Sony usually includes such info.
The manual does have some specs but I am not clear how to interpet the two specs,They are load impedance which it says (over 10 kilohms) and output level at (2 Vrms at 50 Kilohms).I thought it woud be best to test to get a acurate impedance value .Do you Know Which is right? 50 kilohms seems hight for a cd source impedance
The 50 k-ohm is the impedence of the cd input of the pre-amp or receiver. Most are 47 k-ohm with an input sensitivity of 150 mV.

Hope this helps.
It doesn't tell you the output impedance but it does tell you that it is happy seeing a 50K load.
Richingoth, the load is actually before the source(just like speaker to amp). Jasljs, the specs tell you that the cd player will handle 10k load impedance or higher. If you are building a passive preamp, I would suggest a load impedance at about 20k. Load impedance at a minimum is just asking for distortion and phase shift in frequency response.