I have heard an earlier version of the Pass Phono at a friends house and compared that to my Aesthetix IO Signature (now Eclipse with two power supplies) circa, 2008. I though the Pass Phono was an outstanding phono amp as it performed its duties, effortlessly. Compared to my Io at the time, I needed to ensure that I had very quiet tubes and minimized RFI/EMI radiation from cell phones, and other devices. The Io at the time was very sensitive to that type of interference. Now, with the Eclipse upgrade, the power supplies are more efficient, low to imperceptible noise, and upgraded gold caps, and Aesthetix matched tubes, wow, this is a vast improvement over the Io Signature from years gone by. I don’t concern myself with any stray emissions from whatever, it is just an absolute quiet device. The Io Eclipse of today delivers a big, dynamic, and holographic soundstage, with no noise.
Going back to my circa 2008 time stamp when I compared the older Pass Phono with my Io, the Pass Phono is plug and play, while the Io needs some TLC to play competitively. One thing I liked the Io Sig from way back then is that it was more dynamic, albeit with some slight tube noise. Todays Io has no tube noise and is quiet. You can throw away the plug and play analog from the previous generation comparisons, because, now both, are simply plug and play as is. Of course, with Io, you have the luxury (or is it?) of swapping tubes.
