Grateful Dead: Mars Hotel LP recording

Was listening last night, starting with Graham Nash: Songs for beginners, Judy Collins S/T, and finished with MFSL Mars Hotel.  I have to confess, it was a late one, and I tweaked my VTA at the end of the Nash LP. But to my ears, it was better after the VTA change. The Nash LP was a pleasant surprise, hadn't heard it in years. Great listening session, but Mars Hotel was sonically underwhelming. A bit flat, and diffuse….Such great music, but had nothing going on. I hadn't listened to it in some time, but never remembered it was such a subpar sounding record.  A real shame, because it is a NM LP, the old MFSL too. (-: