Aleph Ono/ Xono

Your question is very good, and there seems to be little information on this available.

What little info I have seen indicates (with significant interpolation in my part :)) the circuit topology and circuit is the same if not identical ... Differences in topology are likely to be minor (if any)

I would expect the power supplies to be enhanced, and that the main advance lies here.

I guess Pass Labs explain the difference on their site:

"The Xono is based on the design pioneered in the Aleph Ono. The basic Ono design has not changed but been extend and refined. The separate power supply combined with the additional filtering and dual mono power supply design contribute to the lower noise floor and sonic improvements. The main circuit board layout has been completely revised to reduce noise, shorten the signal path and reduce the length of connecting wires. Sonically critical parts have been optimized and upgraded through continued extensive listening tests. "
As far as I have understood that SuSy-thing (I am not too deep into that matter), it gains its benefits from a balanced topology which the XOno definitely is not.
Like on the Aleph Ono, the inverted output is generated at the end of the whole thing.
As far as I remember - I had an XOno about one and and a half years ago for some weeks - the amplifier circuit itself is indeed nearly identical to that of the Aleph Ono.
FWIW this is my interpretation of Ono. Transformers are separate. Active circuit contained on a small board. To achieve shorter signal path, I mounted resistors on the traces' side (actually I made a mistake). DC coupled, MM stage only.;)


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I wanted to built it fast. The circuit was so small that I had enough space to fit PS (and it's separate for ea. channel). The caps were ROE 1000u, Sprague Extralytics and Panasonic HFQ 150u. I didn't even built an enclosure for 2 separate transformers.

If I would be doing it again I mount phono module directly on TT output, no interconnects.