Question:
What type of tubes does my ADL600 use?
Answer:
The ADL600 uses a total of three tubes on each channel: [2] 6922 and [1] 12AT7A.
The tube in the first position closest to the rear panel is a 12AT7A. The tubes in the two positions directly behind the faceplate are both EH6922 triodes.
Replacement tubes can be purchased from a variety of vendors.