Editing S/PDIF (section)

==Hardware specifications==
[[File:Digital coaxial audio cable (orange).jpg|thumb|Digital audio coaxial RCA connector (orange)]]

S/PDIF was developed at the same time as the main standard, AES3, used to interconnect professional audio equipment in the [[professional audio]] field. This resulted from the desire of the various stakeholders to have at least sufficient similarities between the two interfaces to allow the use of the same, or very similar, designs for interfacing [[Integrated circuit|IC]]s.<ref>Finger, Robert A. 1992 'AES3-1992: The RevisedTwo-ChannelDigital Audio Interface', J.AudioEng.Soc., Vol.40, No. 3, 1992 March, p108</ref> S/PDIF is nearly identical at the [[Communications protocol|protocol]] level,{{efn|Consumer S/PDIF supports the [[Serial Copy Management System]], whereas professional interfaces do not.}} but uses either [[coaxial cable]] (with [[RCA connector]]s) or [[optical fibre]] ([[TOSLINK]]; i.e., JIS F05 or EIAJ optical), both of which cost less than the [[XLR connector|XLR connection]] used by AES3. The RCA connectors are typically colour-coded orange to differentiate from other RCA connector uses such as [[composite video]]. S/PDIF uses 75&nbsp;Ω coaxial cable while AES3 uses 110&nbsp;[[Ohm (unit)|Ω]] [[balanced]] [[twisted pair]].

Signals transmitted over consumer-grade TOSLINK connections are identical in content to those transmitted over coaxial connectors. Optical provides electrical isolation that can help address [[Ground loop (electricity)|ground loop]] issues in systems. The electrical connection can be more robust and supports longer connections.<ref>{{cite web |url=https://blog.teufelaudio.com/spdif-connections-get-connected-not-confused/ |title=SPDIF connections: Get connected, not confused |access-date=2024-05-15}}</ref>

{| class="wikitable"
|+ Comparison of AES3 and S/PDIF<ref>{{cite web |url=http://www.nu9n.com/images/AES3-SPDIF-notes.pdf |access-date=18 January 2011 |title=Interfacing AES3 & S/PDIF |page=2 |year=2001 |author=Dennis Bohn |publisher=[[Rane Corporation]]}}</ref>
|-
! rowspan=2 |
! colspan=2 | AES3
! colspan=2 | S/PDIF
|-
! Balanced
! Unbalanced
! Copper
! Optical
|-
! Cabling
| 110&nbsp;Ω STP
| 75&nbsp;Ω coaxial
| 75&nbsp;Ω coaxial
| [[Optical fibre]]
|-
! Connector
| 3-pin [[XLR connector|XLR]]
| [[BNC connector|BNC]]
| [[RCA connector|RCA]] or [[BNC connector|BNC]]
| [[TOSLINK]]
|-
! Output level
| 2–7&nbsp;V peak to peak
| 1.0–1.2&nbsp;V peak to peak
| 0.5–0.6&nbsp;V peak to peak
| {{N/A}}
|-
! Min. input level
| 0.2&nbsp;V
| 0.32&nbsp;V
| 0.2&nbsp;V
| {{N/A}}
|-
! Max. distance
| 1000&nbsp;m
| 100&nbsp;m
| colspan=2| 10&nbsp;m
|-
! Modulation
| colspan=4| [[Biphase mark code]]
|-
! Subcode information
| colspan=2| [[ASCII]] id. text
| colspan=2| [[Serial Copy Management System|SCMS]] copy protection info.
|-
! [[Audio bit depth]]
| colspan=2| 24 bits
| colspan=2| 20 bits (24 bits, optionally){{citation needed|reason=Not addressed in above ref|date=September 2022}}
|}