DAC 5

The Audio Note (UK) DAC5 Special Digital to Analogue Converter has been specifically engineered for sonic performance rather than technical specification, and fulfils all Audio Note (UK) Level 5 criteria: valve rectification and exceptional materials and component quality.

The Audio Note DAC5 is the most unique digital product available today. It uses the most unusual and innovative digital circuit on the market, combined with some of the finest components, materials, and power supplies possible. Extensive research into the fundamental properties of the data stream itself has shown beyond doubt that, regardless of the theoretical advantages of the signal manipulation employed in our competitors’ products—such as higher oversampling, noise shaping, re-clocking, or jitter reduction—these corrective measures greatly interfere with the critical time-domain requirements of the signal.

Music is a time continuum from start to end, which, when broken, is irreparably damaged. No amount of clever manipulation can restore it to its original time, frequency, amplitude duration, or relationship, regardless of what theorists may claim.

As a result, we have developed a way of excluding or bypassing all these corrective measures, allowing the conversion from digital to analogue to occur without any manipulation whatsoever. All we do is reformat the data stream to enable the converter chip to interpolate the incoming information correctly.

In other words, the Audio Note (UK) DAC5 has no oversampling, no jitter reduction, no noise shaping, and no re-clocking. Having removed all of the digital filtering required for oversampling, all filtering is done in the analogue domain, where it is easier to retain good, wide-band phase-frequency and dynamically coherent behaviour. It uses the highest-grade Analogue Devices AD1865 18-bit stereo converter chip, solely because we found it to be the best sounding available—even better than the 20-bit versions.

The filter-interface coils and transformers are of the highest possible quality, using 80% nickel Super Mu-metal cores with 99.99% pure Audio Note™ silver wire. The air gaps in the two filter coils per channel are matched across the full frequency range to within 0.1dB of each other, using a specially designed program to supplement an Audio Precision System 2 test rig.

The DAC5 Special features an upgraded version of the M6 preamplifier line stage, using a 5814a (ECC82/12AU7a) and a 6463, both of which are dual triode valves. These are coupled to an output transformer wound with Audio Note (UK) silver wire on a High B C-core. With a 33:1 step-down ratio, this output transformer not only has an exceptionally wide frequency response, but also delivers arguably the best dynamic transfer function possible. The analogue output includes provisions for both unbalanced and balanced operation, using the highest quality RCA and XLR connectors.

The DAC5 Signature features an enhanced version of the M6 preamplifier line stage, using a 5814a (ECC82 / 12AU7a / 6189) and a Telefunken 6463, both dual triode valves. These are coupled to an output transformer wound with Audio Note (UK) silver wire on 55% nickel Audio Note (UK) Supa-Perma C-cores. With the same 33:1 step-down ratio, this output transformer maintains exceptionally wide frequency response and superior dynamic transfer. The analogue output supports both single-ended and balanced operation with the finest quality RCA and XLR connectors available.

To power this spectacularly revealing arrangement, we have incorporated a dual-channel power supply with double-choke filtering and valve rectification. This technique provides excellent isolation between the digital circuitry and power supply, and also ensures short, clean, and well-isolated analogue signal paths. The digital power supply is an exceptionally low-noise, shunt-type design.

Internal component quality of this calibre has never before been seen in either consumer or professional equipment. There is an abundance of Black Gate and Cerafine Audio capacitors, as well as Audio Note (UK) Tantalum film resistors throughout the circuit. The analogue stage filter inductors and internal wiring are all produced using Audio Note (UK) 99.99% pure silver wire.