Hes buying it used from a friend, so there may not be a birthsheet.I just purchased an anniversary edition Punch 75. It was listed at 37.5x 2 at 4 ohm. Birth sheet that came with the amp said it actually was 213 x 2 at 4 ohm, so yes I would say they are underrated. The amp should have a birth sheet that tells you exactly what it is actually producing.