I have owned the Viva Auroras with both the 572 and 845 output tubes. Unfortunately I did not audition them against the Lamm M 2.1 nor did I try them on Kharma speakers.
Yours will be a difficult question to answer if you are seeking advice from someone who has made those exact comparisons.
Yours will be a difficult question to answer if you are seeking advice from someone who has made those exact comparisons.