Hi there, tomorrow I'll have the chance to buy at a very good price (for my area) a used DLS40 CR in "as new" conditions. I have some doubts though: the owner told me he bought it as a Ex-demo from a local store, and he used the amp less than 20 times, and everything is perfect and "as new", but he had the bias done at 35. I am no expert in bias and stuff like that, so I ask you: what could it mean? Could it be just for personal taste? What is the default bias on a DSL40CR? Could it be because as a ex-demo the amp NEEDED the bias to be re-set? If I go there to try the amp, how can I spot possible flaws? Thanks a lot!