Audio Note DAC4.1x Balanced - Manual (Page 7)

DAC4.1x Balanced
Congratulations on your purchase of the Audio Note (UK) DAC4.1x Balanced Digital
to Analogue converter.
It has been specifically engineered for sonic performance rather than technical
specification, and fulfills all Audio Note (UK) Level Four criteria: -
Pure Class A operation
Zero negative feedback
Single Ended circuit topology
Valve rectification
Materials and component quality
Extensive research into the fundamental properties of the data stream itself have
shown beyond doubt that, regardless of the theoretical advantages of the signal
manipulation employed in our competitors products, such as higher over sampling,
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, and no amount of clever manipulation can restore it to its original
time / frequency / amplitude duration or relationship, regardless of what the theorists
may tell you.
As a result, we have developed a way of excluding or bypassing all these corrective
measures, to allow the conversion from digital to analogue to be done without any
manipulation whatsoever. All we do is to reformat the data stream to allow the
converter chip to be able to interpolate the incoming information correctly.
In other words, the Audio Note (UK) DAC4.1x Balanced has no over sampling, no
jitter reduction, no noise shaping and no re-clocking. Having removed all of the digital
filtering that is required for over sampling, all filtering is done in the analogue domain
where it is easier to retain good, wide band phase-frequency and dynamically
coherent behavior. It uses the highest grade Analogue Devices AD1865, 18Bit stereo
converter chip solely because we found it to be the best sounding available (yes,
even better than the 20Bit versions!).
The filter-interface coils / transformers are of the highest possible quality, using 80%
nickel Super mu-metal cores. 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.