Installing Optical SPDIF Port

othland · November 2nd, 2009, 01:21 PM

Does anyone know how to install a digital optical (TOSLINK) port? Here's what I'm wanting to do:

I have a device with a SPDIF (coaxial) line-in; I would like to replace the coaxial with an optical port. Does anyone have any clue as to how to do this.

Please do not mention external converters, I know that it is possible to buy an external SPDIF converter.

MTAtech · November 2nd, 2009, 04:50 PM

One is electrical, the other is optical. You will need a device that accepts both, such as an AV receiver.

othland · November 2nd, 2009, 05:21 PM

"I have a device with a SPDIF (coaxial) line-in..."

To the best of my knowledge there is no difference between SPDIF coaxial, and SPDIF TOSLINK other than the connection type. So I would assume that the device would be able to decode a digital signal whether it came over Coaxial or Optical. Is there anything which prevents me from swapping a coaxial input with a TOSLINK input?

If so, what?

MTAtech · November 2nd, 2009, 06:44 PM

Quote:

Originally Posted by othland

"I have a device with a SPDIF (coaxial) line-in..."

To the best of my knowledge there is no difference between SPDIF coaxial, and SPDIF TOSLINK other than the connection type. So I would assume that the device would be able to decode a digital signal whether it came over Coaxial or Optical. Is there anything which prevents me from swapping a coaxial input with a TOSLINK input?

If so, what?

Huh? A coax cable is an electrical cable that transmits an electrical signal. A Toslink cable transmits a beam of light. They are not the same or interchangeable. Some devices, such as DVD players, have a digital coax or a Toslink optical connection for digital audio. Some players have both.

What device do you have that you want to accept digital audio into?

othland · November 2nd, 2009, 09:55 PM

I want to install it into a receiver. The receiver has a digital-to-analog converter (DAC), but only has a coaxial input, no TOSLINK.

"There are no differences between the signals transmitted over optical or coaxial S/PDIF connectors—both carry exactly the same information."
Source: Wikipedia article: S/PDIF

MTAtech · November 2nd, 2009, 10:50 PM

Read the next sentence from your source:

Quote:

Selection of one over the other rests mainly on the availability of appropriate connectors on the chosen equipment and the preference and convenience of the user.

Yes, they both carry the same information and in the same format but one is electrical and the other is optical (light.) There is no way of making the light that comes out of a fiber cable go into a port that is expecting an electrical signal.

Saying that, you need a device that converts the signals from optical to electrical, such as this device.

othland · November 3rd, 2009, 01:58 AM

Yes, well, the light which comes out of an optical cable is eventually converted an electrical impulse.

SOURCE > CABLE > PORT > DAC > AMP > OUTPUT

Indeed, if sound is coming out of a speaker, ultimately all the contributing sound sources are converted into the same sort of electrical impulse as every other source. Digital feeds must be converted to analog by a DAC, and it is the job of the port to send the information from an optical line to the DAC as an electrical impulse. Because TOSLINK and Coaxial S/PDIF carry the same information a single DAC can be, and almost always is, used to convert the digital signal into an analog one.

Obviously, one cannot hook up an optical cable to a device without an optical port. That is why this post is titled, “Installing an Optical SPDIF Port,” and the first line reads, “Does anyone know how to install a digital optical (TOSLINK) port?” Where did you get the idea that I was talking about ramming an optical cable into a coaxial port?

I am amazed that this conversation has degenerated in such a way, and it’s probably best to just let the subject drop. For the record: I was looking for advice about how to attach a TOSLINK port to the internal circuitry of a receiver which already converts S/PDIF.

Thank you for your time, but I suspect that I will do better to simply wing it on my own.

bigBonehead · November 3rd, 2009, 05:11 AM

AMF...

ShyguyXPC · November 3rd, 2009, 06:43 AM

LOL, had to look up and see what that was short for.

MTAtech · November 3rd, 2009, 06:53 AM

Quote:

Originally Posted by othland

I am amazed that this conversation has degenerated in such a way, and it’s probably best to just let the subject drop. For the record: I was looking for advice about how to attach a TOSLINK port to the internal circuitry of a receiver which already converts S/PDIF.

Since that's what I did (see below), you could just say, 'thank you.'

From my post above:

Quote:

Saying that, you need a device that converts the signals from optical to electrical, such as this device.