i bought a few 1960s old cheap tubes from ebay...tungsol..sylvannia..westinghouse...rca..etc (say around 20-50bucks range)
i didnt find a lack of clarity or muted highs...
difference could be airiness or bass impact between each tubes.
v enjoyable amp.
( my dac is the audiogd nfb10.32...i can choose between low or high gain )
Edited by Lorspeaker - 1/21/14 at 7:08am