MEASUREMENTS

I tested the Rotel Michi P5 with my Audio Precision SYS2722 system (see the January 2008 “As We See It”1). Looking first at its behavior via its line inputs, I performed most of the testing with the balanced inputs and balanced outputs and with the volume control set to its maximum. I repeated some of the tests with the unbalanced inputs and outputs with the volume control first set to its maximum, then at 77, which is equivalent to –10dB. (The volume control operates in accurate 0.5dB steps.)

The maximum gain for the balanced input to the balanced output was 18.55dB and for the unbalanced input to the unbalanced output, it was a little lower, at 16dB. For unbalanced inputs, the maximum gain at the balanced output was 23.9dB. The maximum gain at the headphone output was a high 33.5dB. The preamplifier preserved absolute polarity (ie, was noninverting) at the headphone jack and with balanced and unbalanced inputs and outputs. The XLR jacks are wired with pin 2 hot, the AES convention.

The P5’s unbalanced input impedance is specified at 47k ohms; I measured