I just popped in a set of new GT12AX7Ms in my Alembic pre and the tone is awful. Is this what people are raving about when they talk about these tubes? I did notice before installing them that the second tube had bent contacts, it looked like someone tried it and returned it to the store (very professional move by the salesperson ) I put that one in channel two, and at first there was no sound at all, but channel one sounded fine, only the gain was extremely sensitive (very high output). I then removed the second tube (still channel two), straightened the prongs, and did a re-instal and voila, both channels were working at what seemed to be normal output, but the tone is horrible, mids are unnaturally boosted and the treble is clacky and virtually unuseable. Can tubes do this? Or did I possibly inadvertently do some damage to the circuit board?