TA-2022 input impedance ?


Hello, I have a Tripath amp that uses the TA-2022 chip.
I have a link to the data for that chip, but I don't know what to look for.
I need this info to match a passive pre to it.
I know my cd player output impedance but not the amps input impedance. Can anyone look at this data sheet and answer my question?
Almarg, where are you ?
http://www.datasheetcatalog.org/datasheet/Tripath/mXyzxwwu.pdf
128x128zmanastronomy
Right here, Zman :-)

The reason the input impedance is not evident from the datasheet is that it depends on the configuration of the surrounding circuit. Assuming that the input stage is used in the inverting configuration shown in the figures on pages 7 and 16, the input impedance is equal to the value of resistor Ri, the resistor that is in series with the input signal. As you can see, that is shown as 20K for the application depicted on page 7, but it may be significantly different than that for other applications.

Regards,
-- Al
BTW, it looks like the figure on page 16 is drawn incorrectly. In the lower part of the figure, the resistor Ri that is shown as being connected to OAOUT2 should be connected to INV2 instead. The figure on page 7 shows that correctly.

Regards,
-- Al
Thanks Al.
I wish I knew more about this stuff.
I've went ahead and ordered a Lightspeed attenuator for it.
My CD Player is where it should be for that attenuator, but George, the builder of my lightspeed said that the amps impedance should be over 47k ohms for best results.
I guess I'll find out if it's a match in a few weeks.

Thank you for your support Al.
I look forward to reading your input here at the Gon.

John