With the SB's volume control set to its maximum (40), the output level from its RCA jacks with a 1kHz tone at 0dBFS was 1.845V, or 0.7dB below the CD standard's 2V RMS. The Squeezebox preserved absolute polarity??? ie, was noninverting???and the output impedance was a low 223 ohms at midrange and bass frequencies, rising to 549 ohms at 20Hz.