lchapman

My DT 25 was losing power as well until I changed out the tubes (3). Now proper power has been restored to both channels. I hadn't changed the tubes since I've had it. Big difference. They 'cook' over time since they bake upside down (the way they're mounted) and as heat rises, it cooks the tubes. Over time, heat does a number even on good tubes. Anyway, I got my tubes from TubeDepot for $34. I also substituted a ECC83 for the 12AX7, as they are the same tube. The ECC83 was $11 and the two EL84 were $10 each. Shipping #3. I ordered the tubes initially just to check if tubes were the problem, and they were. Simple substitution is quite often used in troubleshooting. I'm an electronics engineer. Wish I could get my hands on a DT 25 schematic. It almost makes me want to buy a Fender tube! There's just so MUCH digital in the D 25. The amp really doesn't have FX's like compression, phaser, chorus, etc. It just has the ability to turn off 2 of the screens in the tubes so that you get a triode out of a pentode tube (as an example). It does have voicing of course, but if you're not into British hard Rock and metal, the voices don't necessarily offer much. I would trade them in a heartbeat for simple compression and a nice phaser built-in. Anyway, new tubes were a big help om power loss!

I am an owner of a DT25 and have enjoyed the amp over 5 years. I am also an electronics engineer. I would certainly like a schematic of my DT25 since the top channel now longer works, and the Low Volume switch in the rear has never worked correctly. As an engineer, I can certainly set the tube bias, etc. I just finished a Simmons Drum amp repair (all IC's replaced) and now on a BOSS Kanana head amp repair. If you could be so kind as to email me a schematic pdf of the DT25, I would be ever so grateful! Thanks, Larry