Thanks! 40K ohms Even if I use the XLR-RCA adapter since I don’t have balanced preamp? Stupid question?
With the [provided] RCA adapters, it’s 20kΩ.
Even if the source resistance is high, the only effect will be attenuation, and very little, like 1dB. This attenuation is not frequency dependent
if good cables are used (low capacitance). I say this to nip the “oh, then you should use these fancy cables” argument in the bud.
Fancy cables are not necessary, and won’t affect the sound unless they are not
designed/built properly. Ironically, the “fancier” the cable (expensive), the more chance they did something like using high capacitance wire, just so it will effect the sound, but the effect is negative! I could go in about such things, but....
Also, the slight attenuation that might happen from sources with output impedance on the high side (including passive preamps) does not cause distortion
, only attenuation.