Audio Note DAC 2.1x valve DAC

[juancho]

The Audio Note 5.1x has been described as the ‘best DAC on the market’ by several reviewers. The 2.1 x DAC is from the same family and the secret of their sound quality is that they operate in non oversampling mode with no digital filtering at all and have zero feedback valve output stages. This particular dac started out in life as a standard 2.1x nos dac but has been extensively modified to improve its sound quality. Modifications are:

· The much revered Black gate capacitors in all critical locations including the digital power supply and cathode bypass positions

· Choke power supply added

· All electrolytic capacitors apart from the Black Gates replaced with Solen or equivalent polypropylene capacitors

· Additional Auricap and silver mica caps used in the psu filtering chain



The picture below shows the massive Solen main psu caps to the left while in the near left you can just about make out the choke and additional filter caps. The digital psu Black Gate FKs are towards the back middle of the picture. You can see additional polyprops on the main anologue circuit board. The 6DJ8s are hardly used NOS.



There are two ways you can use this DAC: 1. As a standard DAC of the highest quality with a tireless sound due to its non oversampling nature and valve output stage. 2. By fitting an LC Audio Clock to the DAC and synching the clock signal back to a suitable transport.



In standard mode, the DAC offers a tireless, highly musical and very analogue sound.



In synched mode the DAC was judged the best-sounding DAC when publicly exhibited to a group of audio enthusiasts last March. Synch mode allows an astonishing increase in sound quality but requires a transport using the same clock speed as the DAC ie 11mghz. For an additional cost to the auction price I can provide an Arcam Alpha 5 as transport and fit an LC Audio X03 clock upgrade.



The DAC works very well with both valve and transistor amplifiers.



The spec below gives the standard Audio Note spec. The unit is in excellent condition and has been little used in its three and a half years of life. It originally cost £1,200 and has had several hundred pounds of new components added to lift its performance by a huge margin.





Audio Note™ Quality Level Two performance
* 24/96 compatibility
* Exclusive 1xoversampling™ direct from disc™ digital circuit
* Valve output stage with no feedback 6DJ8 anode follower with 1,500 Ohm output impedance
* High quality, low noise Beyschlag 1 watt resistors
* Patented Audio Note™ in-house designed and matched I/V interface transformers to get better dynamic interface,
US Patent no. 5,420,585, UK Patent no. 2270595, Australian Patent no. 670611, licence to use this patent is available to both individuals and companies.
* Individually matched analogue filters
* Non-magnetic aluminium chassis
* Customs designed, hand made Audio Note™ copper wired digital input transformer
* Audio Note™ AN-C (red) internal signal cabling
* Audio Note™ aluminium foil paper in oil signal output capacitors
* Both automatic and manual de-emphasis circuits, see rear overview picture later**

This item is currently for dale on E BAY Item number: 7528937927

David