The XP-30 has a low S/N ratio of only 110db's which is a poor number for a three piece system. Why? Old school engineering. Since the early eightie's many designer's including Nelson Pass use local or global feedback technique where the signal current is looped and fed back ("feedback") several times through the Pre-amp then to the ouputs which increase the gain level to the output. The best Pre-amps on the market that are pricey all have S/N ratio's above 125 db's since they are not using feedback looping into the Pre-amp but using a more current technique called feed forward which does not loop the signal current.
The feed forward design was pioneered by FM Acoustics. Feedback results in noise and higher distortion from the parts and boards. The founder and designer of Hegel Audio in Norway, Bent Holter, who has a degree in micro electronics with the emphasis on transistor engineering, took the feed forward technology from FM Acoustics and further enhanced it to a better design he calls his patented Sound Engine technology. The Hegel P-30 Pre-amp uses the Sound Engine feed forward method and the Pre-amp has a S/N ratio of 132db's, the highest ever achieved of any Pre-amp costing up to $20K and higher. The P-30 costs only $7500.00 and performs like a $40K Pre-amp since the noise and distortion is so low which is typical in the best and costliest Pre-amps made.
The feed forward design was pioneered by FM Acoustics. Feedback results in noise and higher distortion from the parts and boards. The founder and designer of Hegel Audio in Norway, Bent Holter, who has a degree in micro electronics with the emphasis on transistor engineering, took the feed forward technology from FM Acoustics and further enhanced it to a better design he calls his patented Sound Engine technology. The Hegel P-30 Pre-amp uses the Sound Engine feed forward method and the Pre-amp has a S/N ratio of 132db's, the highest ever achieved of any Pre-amp costing up to $20K and higher. The P-30 costs only $7500.00 and performs like a $40K Pre-amp since the noise and distortion is so low which is typical in the best and costliest Pre-amps made.