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Digital 101 – I/O Connectivity Specs 5-2-99
Enabling
Technologies – A Connected Digital Progression Unleashed!
Update: See End Of Article –
June 7, 2001
-
PC
Computer Audio Technologies
-
WavToMidi
Conversions
-
Translator
- Pro Sampler Audio Conversions
- SMDI
– SCSI Musical Data Interchange
All of this technology yet how do we
make the connections work for us instead of against us?
How do we keep digital in the
digital domain without converting back and forth in analog formats through
AD/DA converters? The Computer Audio/Video scene exemplifies new digital
opportunities into ‘Desktop Digital Media Creation.’ Everything boils
down to the end result – What’s our preferred method of transport
& delivery now and later including MiniDisc, MP3, MP4, FireWire (IEEE
1394 – i.Link) 400 Mbps; S/PDIF (electrical & optical [TOSLinkTM
mini]), etc.
Trying to connect your CD-ROM S/PDIF
(Sony Philips Digital InterFace) connector to your sound card or MiniDisc
Deck? Having trouble understanding S/PDIF digital I/O connections on
SoundBlaster Live! audio cards and CD-ROM’s? The S/PDIF connector exists
on most CD-ROM drives. Not all CD Drives activate this connection. Even
fewer drive manufacturers mention S/PDIF use.
Just want to have fun preserving
those old 33’s, 45’s or classic 78 LP’s onto your very own CD? Too
much scratchy noise you say? Easy to fix! All of this and more can be done
on today’s PC’s. In this article, we’ll highlight digital S/PDIF I/O
connectivity issues and technologies. The relevancy pertains to sound
cards, CD-ROM’s and MiniDisc S/PDIF (electrical & optical [TOSLinkTM])
connections.
Sony
VAIO Digital Studio –
The
“Digital 101 I/O” title derives from Sony’s 2nd
stab into this web of digital fabric we now weave. VAIO is a graphical
interpretation of the convergence of the analog and digital worlds (sine
wave to the binary 101010). VAIO
(pronounced "vie-oh"), stands
for Video Audio
Integrated
Operation and
represents the concept behind Sony's multimedia computer products.
Sony’s goal of
lifestyle integration is represented by the VAIO concept.
Even
though we do not recommend
a ‘ready built’ PC Computer box, Sony’s VAIO has most everything you
want in one box except room for future expansion.
The
Gotcha’s:
Limited Hardware
Expandability - (1) available PCI Slot and (1) available 3˝-inch concealed
drive bay.
The
Hardware Pluses:
1.) FireWire
(IEEE-1394) a.k.a. Sony I.LinkTM
(S400) – Video / Audio (In/Out) Link.
2.) TOSLink
a.k.a. LightPipe (developed by Toshiba), S/PDIF-optical audio link (AC-3 Dolby
Digital Audio
Out) and
3.) S.LinkTM
(Control-A1 technology) – The Control Link interface, so
far, exclusive to Sony.
Sony
has taken their VAIO PC from a top of the line PII-450, 128 Megs of Ram,
13 Gig HD and DVD-ROM Drive to a PIII-500 with CD-RW. You may still be
able to purchase the PII-450 from either the Online Sony Factory Outlet or
Sony Factory Outlet Store in San Marcos, Texas (512) 396-1882. If you want
VAIO, get a refurbished or customers return merchandise, with same ‘like
new’ purchase warranties for a better deal. To see VAIO, go to
MicroCenter where they may have the older PII-400’s available. Sony
dropped the PII-450’s upon introduction of the newer PIII-500’s. These
PIII’s are too expensive considering what you get for now.
Linking
Technologies –
Although IEEE 1394 is an
"open standard," the i.LINK™ Sony name and logo brand the
digital interface for high-speed communication on Sony products.
Computers, peripherals, audio and digital camera products with i.LINK
ports can be hooked together with a single cable for both data
transmission/reception and control. Eventually we’ll see new motherboard
chipsets, which have built-in native support of these high-speed
technologies. IEEE 1394 / FireWire cables are still pricey and hard to
find. See: www.monstercable.com
S-Link™ (Control A1) Control system was
designed to simplify the operation of audio systems composed of separate
Sony components. Control A1 connections provide a path for the
transmission of control signals, which enable automatic operation and
control features usually associated with integrated systems. For example,
Control A1 connections between a Sony MiniDisc deck, CD changer, and VAIO
Digital Studio Computer provide automatic function selection and
synchronized recording. S-Link™ (Control A1) cables are usually included
with Sony products which support this feature.
Sony
has incorporated another advancement in the digital world with the Optical
Digital Audio Output (TOSLink). This technology transmits digital audio
data from a CD changer to MiniDisc via light impulses (Optical I/O)
instead of conventional electronic signal, allowing for a clearer, crisper
audio recording. TOSLink / Optical I/O cables are moderately priced
depending upon manufacturer. Currently, MiniDisc TOSLink (Optical I/O) is
for single digital copies. SCMS does NOT allow multiple digital copies.
The
Sony Philips
(Audio) Digital
InterFace
– S/PDIF Electrical Or S/PDIF Optical?
Not all S/PDIF connections wearing the
same moniker are the same pin compatible, electrically compatible
connection even though they share the same generic name. Yes they can be
made to connect with a little help.
What’s the difference and why does it
matter? Ever try connecting a Sound Blaster Live (Electrical) S/PDIF to an
(Optical / TOSLink) S/PDIF MiniDisc Deck / Portable? For the purest,
digital is digital and the preferred medium of choice. Once information is
brought into the digital realm such said information is clean without
distortion and reproducible as such. Or think of digital as no loss in
quality over time or copy. An analog signal will eventually degrade beyond
recovery and thus be lost forever. For example those old analog LP 78’s
and 33’s are going to one day be history. Why not preserve their content
by converting old LP’s to digital format thus archiving what otherwise
might be lost. Using a PC for this makes easy use of digital technology
– A different article.
Once
in the digital domain, what if your analog and or digital creations happen
to require yet a different choice of media delivery? This is why we’re
discussing linking technologies. Media changes might require going beyond
converting RedBook audio to wave or MP3 formats or moving from CD-ROM to
PC to portable MP3 Player or MiniDisc or even DAT and of course Computer
Hard Drives. We do have freedom of choice. Yet for now, we have to
overcome some of the connection hassles in the process. Notice also the
polarized organizational alliances of companies involved. Notice the
linking technologies to get us where we want to go with Audio, Video and
Data.
Digital
(Audio) Format Translator –
Unless you’re handy with a
soldering iron, Core Sound offers the ‘Digital
Format Translator’ (DFT) to make your digital
connections interface properly from MiniDisc to Sound Card. Both devices
are digital, yet different formats with different connection requirements.
The ‘Digital Format Translator’
product costs $95, plus $6 for the optional power supply. They also offer
Fiber Optic Cables (TOSLink / mini - TOSLink and Mini-plug). The RCA (S/PDIF)
cables are standard 75-Ohm video cables. MiniDisc recorders are also
equipped with SCMS (Serial Copy Management System) which limits the number
of possible digital copies that can be made (it is not audible and does
not affect analog copying). In other words, this enables a stream to be
marked as an original or a copy. A DAT recorder sold for the consumer
market or digital recording studio component should mark as a copy
anything it records from the digital input. DAT’s are not supposed to
allow the user to make copies of material, which is already marked as a
copy. Many contemporary Pro DAT recorders though may be switched
between consumer and professional mode. Pro mode overcomes SCMS. Does SCMS
(Serial Copy Management System) hamper our creativity? See: www.ria.org
vs. www.hrrc.org
Two
types of electrical
S/PDIF –
One type is commonly referred to as
"Coax S/PDIF." The signal is typically carried along a 75ohm
coaxial (RCA Video) cable. The signal voltage is +/-500mV. The other type
is TTL S/PDIF (Transistor-Transistor Logic). TTL means the electrical
signal is a 5V digital signal. Fiber-optic
S/PDIF is called TOSLink. Less expensive MiniDisc recorders have only
TOSLink digital inputs and outputs. If you wish to record MP3, WAV, or
MIDI from a soundcard, you will need to convert the electrical
S/PDIF output of the soundcard to TOSLink fiber
optic of the MiniDisc.
TOShiba
LINK (TOSLink) Digital –
TOSLink Digital standard was
invented by Toshiba, and is widely used on all Sony digital audio
equipment. TOSLink transmits the S/PDIF digital audio through fiber
optics. The interconnect cables for TOSLink consist of glass or plastic
fiber optic cables that transmit a 660nm red light from the source device
to the recorder's input. There are two types of TOSLink! A.) Home Audio
TOSLink connectors are larger .25" square. B.) Portable Audio mini-TOSLink
connectors resemble 1/8" mini-plug (headphone-type) connectors. Most
portable CD or MiniDisc players have multifunction jacks which act as both
analog and digital input (or output) jacks. When an analog plug is
inserted, the MiniDisc recorder auto-detects an analog connection and
switches on the analog circuitry. When a digital fiber-optic mini-TOSLink
cable is plugged into the same jack, the MiniDisc recorder auto-detects a
digital cable connection.
Coax
Digital standard
–
Many companies utilize the Coax Digital
I/O standard. The connectors for coax are RCA (phono, or Cinch) type
jacks. The S/PDIF digital data is carried electrically on a coaxial cable
(a cable with an active center conductor and an outer-grounded shield).
Coaxial cable is the same as regular 75-ohm RCA or phono cable. Coax's
electrical standards are +/-500mVp-p (milliVolts peak-to-peak). This means
the digital ZEROES are represented as -500mV while the digital ONES are
represented as +500mV.
TTL
S/PDIF standard –
TTL stands for Transistor-Transistor
Logic. TTL S/PDIF is most commonly found on computer CD-ROM drives that
are equipped with a digital audio output. Some inexpensive PC soundcards
also have a TTL S/PDIF input and output. The connector type used is most
commonly a 2-pin header. It is similar to Coax in that the S/PDIF data is
transmitted electrically, however, where it differs is in its voltage
levels. TTL digital ZEROES are represented as 0V, while TTL digital ONES
are represented as +5V.
For
S/PDIF (Sony/Philips Digital Interface) Details:
If you
don’t understand S/PDIF, read it again! Easy to see why most companies
do NOT define S/PDIF standards to the public through documentation. The
easiest way to understand S/PDIF – Just look! Must be that Missouri
blood in me! (Missouri, the “Show Me” State.) Digital IS
the future and the future is NOW! Distribution is the key. Next Up
– MiniDisc, Internet Audio: MP3 & MP4 and Streaming Technologies. It
all gets easier! ;)
Moving
Forward – June 7, 2001 Update
This
article, originally written for print, though dry and l-o-n-g was very
timely considering the Digital Desktop Recording Studio Access Revolution,
which started full force in 1998. No longer were we relegated to consumer
game 16 bit sound cards. We now were getting into affordable access to 24
bit / 96 KHz pro audio / prosumer / working musician worthy audio cards
differentiated by better specs, better drivers, better gear and better
prices from professional level manufacturers who made Desktop Audio
affordable by using PC Computers as our Recording Studios.
As
technology grows, we have new acronyms and terms, greater flexibility
through better interoperability – Yamaha’s mLAN
(1394 - FireWire), ALESIS
20-bit
ADAT
optical (lightpipe) ports, etc. to name a few. We hope by making this
information available, we’ve helped you in making sense of making it all
work together! People And Technology Working In Concert! It’s all about
new ways of invigorating those creative juices @ odd hours when the moment
is right and the genius flows.
Now
CD-ROM’s with S/PDIF are mostly irrelevant since we rip CD’s as wav
files to the HD. Even playback in real time is preferably done digitally.
Apps such as Microsoft’s Windows Media Player 7 play back CD (RedBook)
Audio digitally, not as analog through the little audio cable but
digitally through the data cable. This alleviates other problems with more
CD drives in a PC than a Sound Card has connections for them. A hardware
problem solved by smarter software.
Resources:
In
time, we will update this resource document with further research. If you
have a particular interest or correction, please let us know.
Gill
Boyd,
Former HAL-PC VP Programs
BuildOrBuy Group
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