Circuit to convert coax digital signal to optical?

[bobo box]

I have an AMC CD8b CD player, which i'm very happy with, but which only has coax digital out. I'd like to be able to connect it to my MiniDisc, which takes a TOSLink (optical) digital signal.

Is there a simple circuit i can build to convert the signal? I'm imagining something with a cheap buffer IC and a red LED...



Thanks,

bobo

 

[dsanders]

I don't know of a circuit, but you can get devices for like $60. I have a CO2 midiman that will do this. I know this is not exactly what you asked for but as an alternative if no body else can help. A couple companies make similar products.

 

[bobo box]

Thanks, but i'm fairly sure such schematics exist on the 'net. I've seen one for converting the digital out from a computer's CD-ROM drive to optical, so i would assume that there would be designs for the more common task of converting coax digital to optical digital.


here's hoping... 🙂


-robo

 

[dsanders]

Check out this link, click on view thread. It may not be really what you are looking for. Also you may want to post asking that specific question on that forum I have found that place to be very helpful (start at Oade.com then go to tapers section, then forum) The guy who runs is Doug Oade is very knowledgable and usually helps alot.
http://64.27.110.248/cgi-bin/miva?showmsg.mv+message=1113
The site is geared towards people who record concerts (like the Grateful Dead, Allman Brothers) just so you know what the place is about. Maybe another place to try,
David

 

[rfbrw]

Try this http://www.minidisc.org

 

[Taligent]

If you're intent on building your own I put up <A HREF="http://www.taligentx.com/projects/opticalconverter">a project</A> a while ago - your best best if you just want a single conversion (one input to one output) is to use some of the converters available from <A HREF="http://www.soundprofessionals.com">The Sound Professionals</A> (Audio Hardware -> Digital Converters). At $25 it's hard to beat it by building the unit yourself...I'll get around to updating the page above to reflect availability of this unit.

 

[johan]

I simply used a buffer, a resistor and a red LED. Worked fine. Use a Toshiba TOSLINK module if you want a better light transmitter. Look for schematics at for instance http://www.epanorama.net. Elektor elektronics have also published these types of circuits (splitters, DACs, ADCs etc.).

 

[A'af]

hey folk, would you help me about the change equipment with toslink (optical) output to have coax output, i want build my old Laserdisc player be a transport, I think a few component can added in the box to get coax out, thanks for attn and companion

 

[johan]

Everything you need you should find at http://www.epanorama.net/documents/audio/spdif.html . Consider also to make an optical to coax converter on your receiver if you don't have optical inputs. Optical is sometimes better to use to avoid ground loops (I have experience of this). This is a more expensive solution, though.

 

[tiroth]

Optical gets rid of the ground loops that shouldn't exist considering there should be an AC-coupled pulse transformer in there somewhere. It also adds a pile of jitter.

 

[peranders]

Just wanted to tell you that I've tested 25 meters of nylon fibre, worked allright (no errors) but the light was considerly weaker than the "max" 10 meters. I suspect that it works to about 30-35 meters.

 

[Tieftoener]

The EASY way...

Alright, don't get to involved here. There is an easy way, and it only requires $1.58 + shipping + maybe a short piece of wire. Just get a Toslink transmitter. Toshiba makes some, but Sharp makes some more reasonably priced (same thing as Toshiba w/o the "Toslink(R)". The GP1FA511TZ transmitter can be bought and seen here from Digikey. The price is $1.58 each, and it only requires three connections (see the link above for spec sheet/schematic).

Power it with a 5V supply from the existing PCB in your unit and attach to pin 2 (Vcc), tie pin 3 to ground, and run the coax output line into "Vin", or pin 1.

You could integrate this directly into your CD player chasis, or run the coax digital input into a female RCA connector mounted in a project box with this connector mounted right next to the coax input. Just use a small piece of COAX (I would recommend RG-6) to run from the RCA connector to the Vin pin on the Sharp Toslnik transmitter. Then just add a little battery operated power supply...

It's cheap... its easy... and you get the exact same thing that comes out any consumer DVD/CD/Minidisc player with a toslink output. I just can't understand why some companies dont' put the coax connector on there when they're running the electrical line right to the edge of the PCB and case to mount the Toslink connector/driver... ?!?! Doesn't make sense to me, but who am I?

Anyhoo, good luck -

 

[Tieftoener]

Oh yeah...

Oh yeah, and you can just use a standard Toslink cable then 🙂 Which was my whole point of ease of integration - and it has a semi-professional look too (providing you don't botch up your case with the Dremel 😉

Good luck

 

[A'af]

Hey tieftoener, my player already got toslink transmitter so how come I got coax out from this, perhaps I'll look back to my player to get your mention, thx for the help

 

[Elso Kwak]

Toslink Output

Hi bobo box (these Monnikers get more and more exotic)
Just have a look here:
http://www.diyaudio.com/forums/show...ge=15&highlight=transformerless&pagenumber=7;)
To Toshlink in the schematic means to TOTX174 transmittor😉

 

[emuman100]

I am requiring the direct opposite. I need to convert optical to coax. I looked on the net for those but cant find any that has a toslink receiver on the input, just a TTL level signal. I connected the output of the toslink receiver (The 3 pin receiver from toshiba) to the TTL input of the circuit and I get nothing. The logic high of the output of the receiver is 4V, and the TTL input is a 74HC04. The circuits I'ver tried are here and here and neither work with the receiver. The datasheet with the receiver is here. With either circuits, nothing works. The only thing that is missing is the power supply filter for the receiver. The power supply is 5V which also drives a DC fan. Still, it should work, and noise from a DC fan should not be a problem to get it working. Anyone have any schematics or anything else that may work?

Thanks.

 

[Jocko Homo]

Did someone mention jitter????

Big difference between "it works without errors" and "it adds a plie of jitter".

Which it does. Yuk.

Oh......btw......I probably have some TOSLINK TX & RX parts......ripped out of gear. Yours for the cost of postage.

Jocko

 

[emuman100]

But why doesn't the circuits I've tried with this toslink transmitter work?