First Q is what is the input impedance of the SFM-160 monos? The ARCDB web site posts the following relevant specs for the Ref 3:
"Gain Main output (SE or BAL input): 11.6dB Balanced output, 5.6dB Single Ended output.
"Input impedance 120K ohms Balanced, 300K ohms SE, Inputs (7): CD, TUNER, VIDEO, PHONO, AUX1, AUX2, PROCESSOR. (XLR and RCA connectors).
"Output impedance 600 ohms Balanced, 300 ohms SE main (2), 20K ohms minimum load and 2000pF maximum capacitance. Outputs (3): 2 main, 1 tape (XLR and RCA connectors).
"Maximum inputs 20V RMS maximum Balanced, (10V RMS SE).
"Rated outputs 2V RMS (1V RMS SE) into 200K ohm balanced load (maximum balanced output capability is 30V RMS at less than 0.5% THD at 1kHz)."
Check the rest of your equipment to see if the output impedances of your CDP and DCA match with the input impedance of the Ref 3, and vice versa.
Ditto re the input inpedance of your amp. ARC recommends that it not be less than 20K ohms. Does your amp ask for any min/max output impedance of the linestage.
All of the relevant Ref 3 data is listed above.
BIF