PS Audio DirectStream Junior Owner's Reference Manual page 3

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Thank You
Thank you for your purchase of the PS Audio
Designed by Ted
The PS Audio PerfectWave™ DirectStream Junior Digital to Analog Converter (DAC) is a state of-
the-art DAC, preamplifi er and media center. DirectStream accepts PCM as well as DSD Digital Audio
Smith
data and converts it to high-performance analog audio that can be fed directly to a power amplifi er or
preamplifi er.
DirectStream Junior, based on its larger sibling, the DirectStream DAC, represents a major advancement
in the art of recreating the musical event.
Musical information that may have previously been hidden (or covered up by other DACs) in digital
Uncover What
audio media ranging from CDs to high resolution downloads will be uncovered by DirectStream Junior.
You've Been
Missing
Subtle musical details and cues such as upper harmonics, decay, reverb and room
refl ections will no longer be masked by the conversion process from digital to analog. Your
music will sound natural, and you will be able to rediscover much of what you may have
been missing in your digital audio library with the introduction of DirectStream Junior into your system.
DirectStream Junior features a unique architecture inside. From its digital inputs to its simple output
Unique
stage, DirectStream Junior has been hand written, hand designed and personally voiced by its
Architecture
designer, Ted Smith, along with PS Audio CEO, Paul McGowan and legendary loudspeaker designer
and founder of Infi nity Loudspeaker Systems, Arnie Nudell.
DirectStream Junior is based on a FPGA (Field Programmable Gate Array) as its core processor and
no off-the-shelf DAC chips are used in its design.
DirectStream Junior is less sensitive to the vagaries of input source types and their level of jitter
Less Sensitive to
than most DACs made. Remarkably low jitter sensitivity is one of the hallmarks of this design and
Jitter
is accomplished by not using classic edge transition detection techniques on the digital input data.
Instead, a proprietary method of extremely fast sample-and-recognize technology is employed that
reduces dependency on cables, jitter and the quality of the incoming data source.
Once the data from the selected digital audio source has been input to DirectStream Junior, it is
upsampled to ten times the standard DSD rate of 2.8MHz before any processing takes place. After
processing by DirectStream Junior, all input data is converted to double rate DSD (5.6MHz) and output
through a passively fi ltered solid state analog section.
DirectStream Junior is entirely DSD based, even for PCM inputs. DSD was chosen as the core engine
DSD Based
for this instrument for a number of compelling reasons:
• DSD is simple to convert to analog: just low pass fi lter it.
• DSD is inherently linear: it's hard to build a PCM DAC that always takes the same sized step in
the output for any possible unit increment of the representative PCM voltage value. The best PCM
technology for linearity is arguably a resistor ladder, then all steps are at least positive for a positive
change in the input, but making resistors that are accurate to one part in 2^16 is hard and to one part
in 2^20, very hard. DSD doesn't need anywhere near this level of component matching to achieve its
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Introduction
Owner's Reference
DirectStream Junior Digital to Analog Converter.
Introduction
15-073-01-1
Rev A
DirectStream Junior
ii