A local GC is selling a used three channel Dual Rectifier Solo head. When I checked the back I noted there were mismatched power tubes. The two outer tubes were 6L6 and the two inner tubes were EL34s. The bias switch was in the 6L6 position. When I pointed that out to the GC guy he shrugged his shoulders and said something about it being a used amp. Not sure anyone there had any idea about DRs (to be fair the only reason I know anything is that I have been doing research for a month - reading the manuals for each of the DRs and TRs as well as combing this site and other sites online to learn what I can before buying - clearly that tube combination is not right). I played through it for about 30 minutes and while it generally sounded okay (I'm a Marshall guy and don't have a lot of experience with Mesa amps) I can't believe that tube mismatch will produce the "real" DR tone. The 6L6s lit up normally but the two EL34s did not. Not sure what is the bias voltage difference between 6L6 and EL34 so it may have been that plate voltage in the 6L6 position was just too low for the EL34s.
When I played channels two and three I noticed a very large sound volume difference between the raw/vintage switch position and the modern switch position. The channel volume was at 9 o'clock for modern and required 12 o'clock for raw/vintage for the same perceived volume level. Sound level between the channel one modes of clean and pushed were very close.
My question - Is the difference in channel two/three mode volumes that I described normal for DR Solo Heads? If not, could the non-standard tube combination be a cause or is there something else not right?
Many thanks in advance for your assistance.
When I played channels two and three I noticed a very large sound volume difference between the raw/vintage switch position and the modern switch position. The channel volume was at 9 o'clock for modern and required 12 o'clock for raw/vintage for the same perceived volume level. Sound level between the channel one modes of clean and pushed were very close.
My question - Is the difference in channel two/three mode volumes that I described normal for DR Solo Heads? If not, could the non-standard tube combination be a cause or is there something else not right?
Many thanks in advance for your assistance.
