Digital Audio Sources
Presently we listen to digital audio on Hybrid
systems. Digital signal sources must be fed thru Digital To Analog
Converters then to linear analog amplifiers in order to be
heard on a loudspeaker. Pure digital amplifiers break thru
this last remaining weak link in the audio signal chain and
make it possible to keep the audio in a digital state all the
way thru the amplifier. Digital To Analog Converters are
eliminated and there are many other sonic and financial
advantages as well.
In order to have a purely digital audio system the program
material needs to stay in its digital form through every stage
of electronics from the storage device (like a CD) or
transmission medium (like
satellite signal) to the loudspeaker. This means either everything
needs to be in one box like a DVD Player which includes a pure
digital amplifier and feeds speakers directly or the device
being used as a signal source needs to be equipped with a digital output.
The most common digital outputs used on audio
devices are S/P DIF and TOS or TOS-LINK, AC3-LINK , USB and IEE 1394.
Of courses there
could always be new standards developed when needed. S/P DIF
and TOS are very common and are included on virtually every
new CD player and DVD player manufactured today. We can thank
the MiniDisk (MD) for that. In order for MD recorders to
record MD's they needed a digital signal source. Kind of
like a the which came first the chicken or the egg scenario. You need a digital output to record a digital
MiniDisk. MiniDisks were touted by consumer electronics
manufacturers to be the next personal audio platform but
became overshadowed by the less complex personal MP3 player.
CD Players
Most new home style (non portable) CD Players come equipped
with either a S/P DIF or TOS digital audio output. In the
automotive arena almost no manufacturer of automotive CD players
equipps their CD players with
digital audio outputs. The notable exception is Clarion who has
four CD changers sporting digital optical outputs (TOS). At
least one automotive CD player manufacturer was aware (COOL)
enough to include digital outputs on their CD
players. This makes it much easier for pure digital enthusiasts
to implement awesome audio systems in their cars. All
they need to do is add a pure digital automotive amplifier.
Luckily there are at least 3 models of pure
digital automotive amplifiers being manufactured today. Before
you buy a new CD Player check it out to see if it is equipped
with a
digital audio output.
DVD Players
Virtually all DVD Players come equipped with either a S/P DIF
or TOS digital audio output. In the automotive arena
almost all the DVD players come equipped with a digital audio
output as well. Before you buy a new DVD Player check it out to see if
it is equipped with a digital audio output.
SACD Players
Most Super Audio CD (SACD) players will come equipped with
a S/P DIF or TOS digital audio output. The problem is the S/P
DIF and TOS outputs will only work when you are playing
standard CDs in the player. The SACD signal is a 1 bit Direct
Stream Digital
signal that is not compatible with S/P DIF or TOS. At
this time there is no digital output standard for 1 bit Direct
Stream Digital
digital audio so no high definition digital audio outputs are supplied.
IEE
1394 (Fire Wire) could easily transport the audio data if
desired or yet another digital audio output hardware standard
could be devised for 1 bit Direct Stream Digital. Before you buy a new SACD Player check it
out to see if it is equipped with a digital audio output.
DVD-Audio
DVD- Audio is a competing standard to the Super Audio CD (SACD).
Kind of like the VHS vs BETA phenomenon. DVD-Audio
uses the linear PCM (pulse code modulation) approach to
digital audio encoding. The SACD uses an alternative approach
called Direct Stream Digital (DSD). The SACD format has
several technical advantages. The SACD also has 1 logistical
advantage to record companies. A SACD disk can be played in
either a standard player or a SACD player so only one disk
needs to be manufactured and distributed. Some new players
will be able to play either SACD or DVD-A discs making the
format war less of an issue. Virtually no DVD-Audio
Players come equipped with either a S/P DIF
or TOS digital audio output. IEE 1394 will be used as
the digital output medium in future players. Before you buy a new DVD-Audio
player check it out to see if
it is equipped with a digital audio output, and make sure it
can play both SACD and DVD-Audio disks.
Mini Disk Players
Virtually every MD recorder comes equipped with
a digital input so there would be no signal degradation when
recording. Home style (non-portable) MD Recorders also come
equipped with digital outputs as well. No Portable MD Players come
equipped with digital outputs. One automotive MD player does
come with a digital output however. Clarion makes an automotive MD
Player with a digital audio output. Before you buy a new MD
Recorder or Player check it out to see if it is equipped with a digital
audio output.
DSS Satellite Receivers
Many satellite receivers come equipped with digital audio
outputs. Before you buy a new DSS Receiver check it out to
see if it is equipped with a digital audio output.
Satellite Radio
Virtually none of the announced satellite radio receivers will
come equipped with digital audio outputs. All satellite radio
receivers made for either the XM and Serius systems use
chip-sets made by agere (Lucent) or ST
Microelectronics. Both of these satellite receiver
chip-sets provide digital outputs. But it's up to the manufacturers
of the digital satellite radio receivers wether they should
include digital outputs on their satellite radio receivers or
not. It is very important for "Digital" radio
receivers to be equipped with either a Pure Digital Power
Amplifier or at the minimum a digital audio output so that
consumers will not be closed out using the receiver as a
digital signal source for their pure digital audio system. One reason consumers will want to buy and pay for Digital
Satellite radio is for the increased audio quality. By the time it gets to the receiver the audio signal has traveled
more than 45,000 miles in a digital format it would be a shame if it
couldn’t make it that Last Inch to your pure digital
amplifier. Before you buy a new Satellite radio receiver check it out to
see if it is equipped with a digital audio output.
Cable Boxes
Many cable TV boxes come equipped with digital audio
outputs. Before you subscribe to a cable TV or cable DMX
service check it out to
see if the cable box is equipped with a digital audio output.
It might make more sense to get a DSS receiver instead
if you're setting up a pure digital audio system.
Compressed Media (MP3 / AAC /
WMF) Players
Virtually none of the portable MP3 / AAC / WMF
Players on the market come equipped with digital audio outputs.
A few manufacturers of Home style (non-portable) players
include digital outputs. Before you buy a new MP3 Player
check it out to
see if it is equipped with a digital audio output.
Personal Computers
Virtually every computer on the market
come equipped with some kind of digital input and output. The
most common type is the USB or Universal Serial bus. Some
computers like the Apple iMac and Sony VAIO come equipped with
one or more IEE 1394 (Fire Wire) ports. Both the USB and
IEE 1394 (Fire Wire) ports can support the transmission of
digital audio. The IEE 1394 port has enough capacity to
transmit hundreds of simultaneous channels of CD quality audio
or SACD audio or even several channels of hi definition
video. Digital audio output cards are available for Personal
Computers that provide S/P DIF and TOS digital outputs as
well. Before you buy your next computer check it out to
see what kind of digital inputs and outputs it is equipped
with.
New Devices
As technology progresses there will certainly be new sources
of digital signals to consume. We should always be aware of
the connectivity options available on new equipment we
purchase so we can make the best choices. That digital input
or output might not seem so important right now. But in the
future you may be closed out of using your legacy equipment in
a pure digital system if it lacks the proper
digital inputs or outputs. Before you buy your
next TV Set, VCR, PVR ect. check it out to
see what kind of digital inputs and outputs it is equipped
with.
Digital Video Sources
Digital Video Cameras
Most digital video cameras on the market have an IEE 1394
digital output. Some digital video cameras on the market
have a digital recording medium like tape, Compact Disk or
Mini Disk as well. Before you buy your next Hi Definition
TV Set, VCR, or digital camera check it out to
see what kind of digital inputs and outputs it is equipped
with or what type of digital media it uses.
Digital Video recorders
New digital video recorders should have an IEE 1394
digital input and output. Before you buy your next
Digital VCR or PVR check it out to
see what kind of digital inputs and outputs it is equipped
with.
Digital Television Sets
New Digital TV sets and Hi Definition TV sets should have an IEE 1394
digital input and output. Before you buy your next
Digital TV sets or Hi Definition
TV Set check it out to
see what kind of digital inputs and outputs it is equipped
with.
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