Symetrix 620 20 Bit Analog Digital Converter Sample Rate Audiophile ADC SRC [Refurbished]
( 283650195422) )
Tested/Guaranteed • Audiophile Quality • 20 Bit ADC • 1U Rackmount • 115V/230V AC Internally Switchable
Photos show the actual item for sale
Item is very lightly used and in fair to good cosmetic condition. It has been tested to confirm that it works as it should. The photos show the actual item for sale.
- Mixing to DAT, MD, Hard Disc etc
- CD Mastering
- Sample Library Mastering
- Multimedia Mastering
- Outboard A/D for hard disk & modular digital multi-tracks
More detail may be found in the User Manual
- 20 bit quantization
- Selectable dither & noise shape
- Selectable output word size
- AES/EBU & S/PDIF in and out
- Real time sample rate conversion from 44.1 to 22.05 for multimedia
The Symetrix 620 is an outboard 20 bit A/D converter for faultless transitions between analog and digital domains. If you're presently using a 16 bit recorder or workstation, the 620's dither and noise shaping functions can markedly reduce your low level noise and distortion. If you've already moved up to 20 bit equipment, then chances are good the 620 will provide a clearly audible improvement over your internal A/D converters.
The unit can be switched between 115V and 230V AC power via an internal switch. See the final image below for details.
How exactly, can the 620 improve the sound of my 16 bit mixes? Although 16 bits can theoretically give you 96 dB of dynamic range, the fact remains that low level signals are not well represented by the lower bits of a 16 bit word. One of the advantages of analog tape was that low level audio could fall below the recorder's noise floor and still be discernible. Not so with digital. Undithered signals that fall below the digital “quantization" level are lost and gone forever, covered over by quantization noise. If your console boasts a 110dB dynamic range and you mix to a 16 bit DAT (even if it's equipped with an 18 bit converter), your dynamic range is reduced to 96dB at best. Even if you feed your DAT digitally from a 20 bit A/D, the DAT will simply throw away (truncate) the last four bits. No questions asked.
The solution is to capture the detailed analog audio (which in many cases has well over 110dB of dynamic range) and intelligently process it into the 16 bit storage medium. The 620 does this through use of dither and noise shaping. The 620's dither algorithm (D16) improves the effective dynamic range of 16 bit sounds (or 8 bit if you're working in multimedia), by changing the characteristic of quantization noise from a harsh, signal related distortion to a smooth hiss. The D16 algorithm is used when the signal is headed for further digital domain processing such as editing, compression, EQ, etc.
If you're mixing to your final destination (such as DAT) and your signal will undergo no further digital processing, select the NS16 algorithm which is a combination of dither and noise shaping. When converting from 20 to 16 bit resolution the 620's noise shaper moves the quantization noise out of the midrange region where the human ear is most sensitive. (See graphs below.)
What sets the 620 apart from the internal A/D converters that came with my equipment? Lots of things. Most internal A/D converters are “bare bones". The 620 carefully integrates a 20 bit delta-sigma IC with a powerful DSP processor to noise shape, dither (technically redither), downsample (44.1 to 22.05 conversion) and remove DC in the digital domain.
(file photo, actual implementation may vary)