Yes, The Dac is the only tube gear I have too. The rolling is a LOT of fun, as it can be done on the fly with the rectis, but you have to turn down the volume on the amp (or switch off) when rolling the output tubes. As they are all on top and easily accessible, it is very addictive and loads of fun. Very powerful feature, as you can vary the presenatation enormously. I am also lucky to have a local tube guy who sells a lot these tubes very, very cheaply. At his cheap prices, I cleaned him out! However, even on Ebay, you can get a lot of these tubes without breaking the bank: 6A3/6b4g(with adapter) is still at good prices, 5u4g/5y3/type 80 and 83 (with adapter) also very reasonable.