Dear @scar972 : Levinson founded Cello in the mid 80's ( I think ). I had the opportunity to listen his amp Duet and the Audio Suite with its integrated phono stage board ( the AS was a modular design for the customers choice what they need.) and I listened too his equalizer Pallete. Cello made it too speakers but I never listen too and obviously he designed what was and maybe is one of the 3 best ever open reel machines the : ML-5a ( half inch.Well in its times was considered the ONE the BEST ).
However when he was/still working at Levinson company the " brain designer ", with out dimishining Mark in any way was J.Curl. I still own the 20.6 monobloks based in J.Curl design and I think that some Agon audiophiles remember the Vendetta Research phono stage that JC designed when he left Levinson/Madrigal
company and latter on his Blowtorch pohono stage too.
In the electronics today Parasound the JC models were and are J.Curl designs.
R.