Aragon 4004 impedance?

I'm hoping that someone here can help me by providing the input impedance for the Aragon 4004 amplifier, as I'm matching it up to another component and need this information. I tried looking for a manual online, but unsuccessfully so. Can anyone assist?
According to this link about the 4004 mk II, the input impedance is 22 Kohms. If memory serves me right, the input impedance did not change between the original 4004 and the mk II revision. However, on that link there is a way to contact Aragon or Indy Audio Labs for technical support from the menu on the left hand side of the page. Perhaps they could be of more assistance.

Thanks so much for your replies - that was what I needed.