How do I hook up a SPDIF digital output to an analog input (RCA or 3.5mm stereo plug)

[Borg20001]

I'm trying to see if I can patch these two things together. I have an older Vizio HDTV with SPDIF digital audio output and I don't have a home theater set up but I do have an old Logitech Z540 5.1 setup.

Is there any way I can hook up the SPDIF digital output into the analog input for the Logitech Z540 or even to the analog RCA inputs for an older soundbar?

I was wondering if this connector would work to modulate the digital output to an analog signal for the speaker systems that I am limited to at this point (from a budget standpoint -since I have no budget left).

http://www.monoprice.com/products/product.asp?c_id=104&cp_id=10423&cs_id=1042302&p_id=6884

If this link would work, then would all I need be a digital TOSlink cable to get the digital audio output from the back of my TV into this "modulator" and then just connect the analog output from the modulator to my speaker system (either the Z540 or the soundbar)?

Appreciate any feedback.

 

[Howard]

It looks like that would work, but only if your TV can output stereo PCM.

Get yourself a receiver later.

 

[Borg20001]

It looks like that would work, but only if your TV can output stereo PCM.

Get yourself a receiver later.

Thanks Howard. I just had a chat with tech support at Monoprice and they told me that I need to find a converter that will support compressed audio signals. So their converter will not work with the output from TV's unfortunately.

So I am trying to figure out what keywords I should put into my google search to see if there is anything out there that will convert my signal that doesn't cost more than just buying a HT system. May be stuck I'm afraid.

 

[Howard]

Run the S/P-DIF to your computer and run your sound card's line-out to your speakers? Your motherboard or sound card should have a digital-in.

 

[Borg20001]

Run the S/P-DIF to your computer and run your sound card's line-out to your speakers? Your motherboard or sound card should have a digital-in.

Thanks, I thought about that but my desktop is in another room so I'd need a good amount of cabling to connect them.

 

[Ross Ridge]

Note that most of the time your TV won't be outputting compressed Dobly Digital (or DTS) through its SPDIF output. Mainly it'll just be plain PCM, with most TVs the the only time they'll output Dolby Digital is when you're tuned into a TV show (using the TV's internal ATSC tuner) that happens to have a DD 5.1 soundtrack. Your TV probably has a setting to downmix this automatically to two channel PCM.

If you want to actually get 5.1 surround sound from TV shows broadcasting with DD 5.1 then what you need is a Dobly Digital decoder box. I'm not sure if they're generally available or cheap. If you want 5.1 surround from a DVD player or something like that you've connected to the TV by HDMI you'll need to get an AV recevier and probably a new set of speakers.

 

[SithSolo1]

Dolby Digital decoder boxes are hard to come by and usually more expensive than a basic receiver.


I can't imagine a TV having Optical out but not RCA analog out. Can't us just do analog to analog?

 

[Borg20001]

Dolby Digital decoder boxes are hard to come by and usually more expensive than a basic receiver.


I can't imagine a TV having Optical out but not RCA analog out. Can't us just do analog to analog?

Thanks for the feedback Sith,

Unfortunately, the TV I have does not have analog audio out - only SPDIF optical audio out. When I picked it up, I still did not know the nuances of the various TVs so I was not even considering the need for analog audio out.

Its a Vizio which may explain much. Here's a link to the specifics on this TV -
http://www.vizio.com/led-lcd-hdtvs/m470vt.html?___SID=U

So unless there is an inexpensive fix out there, I think I may be doomed to watching HDTV with tinny audio.

Any ideas?

 

[nsafreak]

Nope, unfortunately you're stuck without some kind of receiver to take the digital signal that the TV is outputting to an analog signal that your speakers can play. You might want to check your local craigslist and see if there's somebody looking to sell a receiver cheaply.

 

[Ross Ridge]

So unless there is an inexpensive fix out there, I think I may be doomed to watching HDTV with tinny audio.

Change the "Digital Audio Out" setting of your TV to "Force PCM". Page 38 of the manual.

 

[NutBucket]

One thing that you haven't mentioned is what video sources you are using. Depending on what your setup is, you could simply bypass the tv by connecting the speakers directly to the dvd player, cable box, etc.

 

[Borg20001]

Change the "Digital Audio Out" setting of your TV to "Force PCM". Page 38 of the manual.

Okay so if I understand this correctly - If I buy this converter at monoprice: http://www.monoprice.com/products/pr...2302&p_id=6884

And then get a digital TOSlink cable to get the digital audio output from the back of my TV into this "modulator" and then just connect the analog output from the modulator to my speaker system (either the Z540 or the soundbar).

The I would need to change my Digital Audio Out setting to "Force PCM" - then I have a work around which will not produce 5.1 sound but will enable the digital audio out signal from the TV to send a signal through the converter to the analog sound system that I have so I can get either the sound bar going or the Z540 with subwoofer producing the sound from the TV - more or less.

Is that correct? Not an elegant fix but one that will get me louder (if not better) sound than the regular TV speakers produce....right?

 

[Borg20001]

One thing that you haven't mentioned is what video sources you are using. Depending on what your setup is, you could simply bypass the tv by connecting the speakers directly to the dvd player, cable box, etc.

Yes, I have an XBox 360 that plugs into the TV via HDMI and a BluRay player that also plugs in via HDMI. My regular TV comes in via the coaxial cable that goes directly into the TV as well. I think only the BluRay player might produce the 5.1 signal and I can hook that up to the Sound Bar via the RCA connectors. I can also use an 3.5mm to RCA splitter cable to patch the RCA outputs into a stereo 3.5mm input for the old Z-540 5.1 PC speaker system - I think. But I have nothing to get the 360 audio to either of the external speaker systems that I have (unless I go 480 p by using the regular XBox 360 connector and patch off the two RCA cables from that to either speaker systems.

 

[Ross Ridge]

Is that correct? Not an elegant fix but one that will get me louder (if not better) sound than the regular TV speakers produce....right?

That's the idea. According to the manual (pg 25) the SPDIF output "is active when receiving audio with the programs being viewed no matter the what input is selected", so it should work with any source.

 

[Borg20001]

Thanks for your advice. I ordered the converter and a tos optical 5.0mm cable and we'll see if it all works with the Vizio TV's digital audio output. I now know how to change the audio output to Force PCM so I'll see how it all goes and leave an update here in case anyone is interested.

Thanks again. Let's hope it all works like I think it will.

I picked up one of the Bose Companion 3 series II pc speaker systems on clearance at Target for cheap so I may try that 2.1 system with this before I hook the Bose system to my PC and switch out the old Logitech z-540 system.

 

[Borg20001]

Update, I bought the converter and a TOS link cable, hooked it up to the TV's SPDIF output and set the TV Audio to Force PCM, then hooked up the RCA cables to the input for the soundbar and it works fine.

I'm going to try to hook it up next to a 2.1 PC Speaker system using a stereo RCA to 3.5mm jack connector and see if I can get the subwoofer to work from that audio signal.

Thanks to all here for their input.

 

[NutBucket]

Glad it worked out for you.

 

[thomsbrain]

I probably would have bought a $20 used receiver on craigslist, but that's probably a lot easier to mess with and uses less power.