How do you bias the tube sets without an attenuator turned full counter clockwise?
Lacking deep bass, compared to what (speakers and amplifiers)? According to the manual Velodyne Room Optimization program I'm getting almost the same frequency depth on my Avalon Eidolons as compared to a pair of Hypex nCore 400s. The trace for the VTA 180s is slightly fatter around the 30-50Hz region. I personally prefer the what the VTAs are doing for general listening. The nCore are relegated to my little recording studio were the overall presentation is more useful than tubes.
Keep in mind we're getting into the subjectivity of our differing rooms. My listening room is on the large size with a vaulted ceiling, using more reflective diffusers and little in the way of absorption
Lacking deep bass, compared to what (speakers and amplifiers)? According to the manual Velodyne Room Optimization program I'm getting almost the same frequency depth on my Avalon Eidolons as compared to a pair of Hypex nCore 400s. The trace for the VTA 180s is slightly fatter around the 30-50Hz region. I personally prefer the what the VTAs are doing for general listening. The nCore are relegated to my little recording studio were the overall presentation is more useful than tubes.
Keep in mind we're getting into the subjectivity of our differing rooms. My listening room is on the large size with a vaulted ceiling, using more reflective diffusers and little in the way of absorption