converting optical to rca analog

[kazoo]

Hey guys,
Here is my situation. I have a 400 disk changer in one room and want to run the signal to my other setup in another room. I was thinking of running an optical cable from the cd player to my tube setup and then converting it to rca analog so I can hook it up to the preamp. The run would be about 25 feet so I don't want to run a normal cord that far. Is there anything out there that would decode the signal and still keep the quality of music high. Just looking for opinions if this is possible and what I can use. Thanks for any help.

John

[ckng]

Hi,

Other than a DAC which takes optical in (TOSLINK) I can't think of any other way you can do what you want. Not sure also if there are optical cables that are 25' long.

Regards
CK

[kazoo]

Hi, thanks for the reply. The optical cable is not a problem. I found a couple of places that sell 5m lengths real glass cable or also a place that has 30 ft (9M) real glass cable. I was thinking I probably need a DAC, so which one do you recommend. I need something good that won't cost me a fortune.
Thanks,

John

[phn]

It doesn't matter if you use optical or SPDIF/RCA as long as the signal is digital.

Google TDA1543 DAC.

[mrshow4u]

It's good that can get real glass optical cable for that length of a run. I had a situation where I had to connect two TOSlink (plastic) cables to increase the length and the results were iffy. I believe there is a ton of attenuation (per foot) on the plastic stuff when compared to glass.

...are you saying that there's a TOSlink connected cable that is real glass? ...or are you using something else? ST, FibreChannel, etc??

[kazoo]

Originally posted by mrshow4u

...are you saying that there's a TOSlink connected cable that is real glass? ...or are you using something else? ST, FibreChannel, etc??

Its real glass optical cable with toslink ends. If you do a search on ebay for glass toslink you will get couple of places that sell them. I bought some while back and they work real good. They dont yellow and the bend radius is 2 inches I believe.

[kazoo]

Originally posted by phn
It doesn't matter if you use optical or SPDIF/RCA as long as the signal is digital.

Google TDA1543 DAC.

Thanks I will check this out. But I think it would be cheaper to run optical cable than a digital cable that long.

[mrshow4u]

Thanks I will check this out. But I think it would be cheaper to run optical cable than a digital cable that long.

...Cheaper?? Hmmm. I use Belden 1505A (RG-59) with Canare 75 ohm RCA's (or BNC's). The crimper and stripper was expensive, but you can buy made to order cables for not too much. I've looked at the termination side of the transmission line (interconnect) and the signal quality remains very good. ...even at 100 meters!!

Thanks for the info about glass on TOSlink, that's good to know.

One thing to keep in mind: I have to perform jitter measurements in my daily work and optical jitter is always worse than copper, for a given system. I/we think it's because of duty cycle distortion in extinguishing/illuminating the LED. The total jitter can be still, very low.

[kazoo]

Originally posted by mrshow4u


...Cheaper?? Hmmm. I use Belden 1505A (RG-59) with Canare 75 ohm RCA's (or BNC's). The crimper and stripper was expensive, but you can buy made to order cables for not too much. I've looked at the termination side of the transmission line (interconnect) and the signal quality remains very good. ...even at 100 meters!!

Thanks for the info about glass on TOSlink, that's good to know.

One thing to keep in mind: I have to perform jitter measurements in my daily work and optical jitter is always worse than copper, for a given system. I/we think it's because of duty cycle distortion in extinguishing/illuminating the LED. The total jitter can be still, very low.

Well I stand corrected. Thanks for letting me know about the Belden 1505A and using it as a digital IC. I guess what I was worried about is the resistance running it that long. I though it be better to run the optical but now you brought up jitter. I can't remember but I think the changer only has optical and analog rca outs. Well first I need to find a good dac and then I will figure out the cable. Any good kits out there already put together using the TDA1543?