Pro Ject Phono Box DS3 B Balanced MM MC Phono Preamp Color:Black the proprietary HDAM circuit has 100 300 the proprietary HDAM circuit has been further optimized from its previous version by placing the parts symmetrically on the audio board and creating a more direct signal path But these feet are also adjustable to bring the platter perfectly in balance for the most accurate tracking of the needle in the groove By keeping the gain stage fully symmetrical we can optimize the signal to noise ratio the Phono Box DS3 B allows you to upgrade to True Balanced operation with a MC (Moving Coil) cartridge on most Pro Ject turntables