I have received some e283cc(philips SQ). I see that the pin out is different than a ecc83 but the circuit characteristics are the same. I also have a mono block set that has an ecc83 input stage tube. This input stage is for impedance changing involving little gain. However, it is also a big player in the sound of the amps as I have experimented with many types of ecc83 tubes in this position(teles, mullard RCA Jan sylv). What could be expected in sound changes by changing to the better spec tube? Better than 5751/e83cc? Could try a conversion socket, but doesn't seem to me to be adequate for a fair comparison. Anyone with some experience concerning converting to this tube?