Passive preamps and poweramp's input impeadance


I have a Rotel poweramp with 33khoms input impeadance, and thinking about driving it with a Creek OBH-14, which is a passive preamp/DAC combination. I have been advised that the Rotel's input impeadance may be too low..
How would this affect the sound etc..., and would it be a bad idea? (I'm unable to test before buying). The Creek would also be driving a NHT SA-2 sub amp.. which I do not know the input impeadance for.
Your comments would be greatly appreciated.
arni
I think Symphony Sound is right. Working and optimizing are birds of a different feather. Arni, the Rotel's input impedance does make for a classic candidate for a passive pre. Not knowing the source specs or cableing prohibits a defintive answer. The fact that it will be driving a sub amp as well, doesn't bode well.
Arni, please forgive me. I made a huge error in my previous post. It should have read as: "the Rotel's input impedance does *NOT* make for a classic candidate for a passive pre."
I will third Symphony and Unsound. 10k into 23k is not too good. HOWEVER, it is not the numbers that need to be matched but the impedance curves. I am not familiar enough to know how linear amps' impedances change with frequency to give you many details but if you can find the curves for your two pieces, all you have to do is superimpose them on each other and make sure that they don't hit (the axes will have to be similar of course). Theoretically you could have the preamp's lowest Z equal to the amps highest and still be ok if they don't hit (i.e., are offset). Otherwise the signal will be reduced audibly. So, Pass is right in some situations but if you change the amps or preamps, all bets may be off. Good luck on this tough one. You may just have to experiment and see what you think with your ears since that is what counts in the end anyway. Arthur
Another thing to calculate, that no one seems to be considering, is the actual output impedence of the passive which changes with the setting of the volume control (which will vary depending of the output of the source). The output impedence of the creek, according to its manual, swings from 50K to 0. This is too complex for me - math wasn't my best subject, but logic tells me that with the variable output impedence of the Creek you should listen to it in your system before you reach any conclusions.
There you have it! Newbee has given us some insight on how the impedance curve behaves. Sounds like what we said is right afterall. You'll have to experiment with this one! Arthur