All tests of the Upstate Audio SL20/20-2 Sonic Lens run on our APx525 system garnered stellar results. Taking the top off of the unit reveals a power supply built for the long haul, providing enough headroom for the most demanding audio tasks and beyond. In fact, the power supply takes up nearly two-thirds of the SL20/20-2’s internal real estate and, according to designer Matt Lesko, is over-built using large components because of their reliability.
Interchannel crosstalk was subterranean at -126 dB.
Frequency response through the unit was razor flat (less than 0.2 dB) to the limits of our test system between 10 Hz to 80 kHz (at 1kHz ref. level).
Interchannel phase deviation was a miniscule 0.002 degrees
Using a variety of gain and fine-tune adjustments, we were able to take the unit up to +25.5 dBu before the onboard overload light shined.
The signal-to-noise ratio tested consistently left and right at +91.6 dB.