Sorry for the late reply and as always , thanks for the insight . I can now understand a bit better the constraints Rune is limited by I sent an email to Allo regarding this , I think the Piano 2.1 can be made a lot more flexible . In fact , as a DSP is involved , I'm pretty sure that DAC could even be configured for balanced operation .
I had a play this evening with an active sub which was promising but not ideal considering my mains are big 15" co-ax drivers and the Koda 8 is an 8" driver in a considerably smaller box . Extremely easy to set up , so I have high hopes for a 2.2 full active setup in future
Pi3 , Kali / Piano 2.1 (with dedicated choke input PSU) ----6SN7 beta follower---BUZ900P choke loaded source follower---Beyma 15XT in 230l cabinets/TPL150H AMT .