Monolith is spec'd at 28 kiloohms...
Thank you, I had one too many zero, corrected now.
Yamaha pre out specs:
Rated Output level / Output impedance
Pre Out except subwoofer (1 kHz)..............................1.0 V/470 ohm
Maximum output level..................................................2.0V or more
May as well do the math right here just for fun, and since in this case everyone seems to know Ohms law.
V = I*Z0 (Z is load impedance, i.e. input impedance of the Monoith)
Say V = 1 V
Z = 28,000 ohm
I = V/Z = 1/(28,000+470) = 0.000035125 A, or 0.035125 mA
Voltage drop = IXZout (Z0 is the output impedance of the RX-A1070)
So voltage drop = 0.000035125 X 470 =
0.0165 V, or 16.5 mV
For two power amps in parallel per
@M Code
I = V/Z = (1/(28,000/2)+470) = 0.0000691 A, or 0.0691 mA
Voltage drop = IXZout = 0.0000691X470 =
0.03248 V
So the slight drop (extra drop due to the lower parallel input impedance of the Monolith) is:
0.03248 - 0.0165 = 0.01597 V or 15.97 mV
15.97 mV difference in output is negligible, but M code is absolutely right about the slight difference, especially if the preamp has relatively high output impedance (e.g. passive preamps) and the power amp has relatively low impedance. In the case of the RX-A1070 and Monolith 200 WX5, there should be no issue.