I need to connect an electric piano with stereo RCA outputs to a mic (or line) XLR input on my DR-680. I am looking at either the Radial Pro AV2 or Switchcraft 702CT. Either should do very nicely.
However: the manual for the Radial Pro AV2 says the output (mic) impedance is 600 ohm, while the Switchcraft 702CT manual lists 50 ohm. I seem to remember reading somewhere that it is a good idea to have at least a 5x ratio between the mic output impedance and the input impedance of the preamp. The DR-680 preamps have an input impedance of 2400 Ohm.
That would make the Radial Pro AV2 a tight squeeze at 4x while the Switchcraft 702CT would be no problem at all.
Any advice? Do I have things confused with the impedance? Other suggestions for a good DI for this purpose?
Regards, Christine