Hi! I have been reading this forum for a long time now and now it's my first post. So a big hello to everybody and thanks for the great infos I found so far. From all the great comments I saw, I decided to buy a DT-50 head with the 412 cab. It's been 2 months now and I can't get the good sounds you seem to have. It's my first tube amp, so I don't really know what to expect. But the real problem I have, is with topology I. The volume is alot lower than the other topologies. I upgraded the firmware and no changes. I submit a ticket and they told me it's normal. But I can't understand why the sound is so loud on all the other topologies and not on the first. There is no way I can stand just in front of the cab with the volume at 12oclock in topo II, III and IV. But in topo I, I can put the channel and master volume all the way up and it's not breaking my ears. And the things that bother me the most is the volume is louder with the master volume pulled out..... With volume knob pushed in, there is almost no change in volume level from 5 to 10... And it's only in topo I. In the other topologies, if I am in full 50watt operation I can wake up everyone on the street :) I opened the back to check if the lamps where all seated. I removed and reput the in place. I saw the left EL-34 looking different than the right. The filament is not protruding on the top, I don't know if it's ok. And it's seems to get burn marks inside the tube. Is it normal? I used the amp for no more than 6-8 hours since I bought it new. During operation, the right lamp (looking from the back) emit a blue haze but not the left. This blue haze get brighter with more input from the guitar. Check the video on youtube http://youtu.be/nbBcwm_9eb8 I put another video too where you can see and what I am talking about if I was not clear. It's start in topo I with knod pulled out. Check the volume is almost the same with knob pushed in, but only in this topo... http://youtu.be/CWQOmBJhECY Anyway, I would appreciate if you can tell me if the amp is not operating like it should. In that case, I would submit another ticket. In the left tube the heater filament is a lot shorter It's difficult to see, but the glow seems to be better in the right tube Is this normal "burnt" marks? This amp was on not more than 8 hours in total. The left tube is weird looking, no? Could it be only a bad tube that is causing my problem? Or the tube got bad because of an amp trouble?