T+A MP 2000 R Mk II, User Manual

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8
Introduction
PCM and DSD
Two competing formats are available in the form of PCM and DSD, both of
which are used to store audio signals at very high resolution and quality. Each
of these formats has its own specific advantages. A vast amount has been
written about the relative merits of these two formats, and we have no intention
of participating in the dispute, much of which is less than objective in nature.
Instead we consider it our task to develop equipment which reproduces both
formats as effectively as possible, and exploits the strengths of each system to
the full.
Our many years of experience with both systems have clearly shown that PCM
and DSD cannot just be lumped together; it is essential to treat each format
separately, and take their specific requirements into account. This applies both
at the digital and analogue level.
For this reason the
MP 3100 HV employs two separate digital sections, two
D/A converter sections and two analogue back-ends - each optimised for one
format.
MP 3100 HV and DSD
By its nature the DSD format involves a noise floor which rises above the range
of human hearing as frequency rises. Although this noise floor is not directly
audible, it does subject the treble units in the loudspeakers to a significant
load. It is also possible for the high-frequency noise to cause distortion in many
low-bandwidth amplifiers.
The lower the DSD sampling rate, the more severe the inherent noise, and it
cannot be disregarded, especially with the DSD64 format - as used on the
SACD. As the DSD sampling rate rises, the high-frequency noise becomes
increasingly insignificant, and with DSD256 and DSD512 it is virtually
irrelevant. In the past it has been standard practice to apply digital and
analogue filtering processes in an attempt to reduce DSD noise, but such
solutions are never entirely without side-effects on sound quality. For the
MP 3100 HV we have developed two special techniques designed to eliminate
the sonic disadvantages:
1.) The

True-DSD technique, consisting of a direct digital signal path
without filtering and noise-shaping, plus our True 1-bit DSD D/A converter
2.) Analogue reconstruction filter with selectable bandwidth
The

True-DSD technique is available for DSD sampling rates from DSD64
upwards.