Optical audio out (via toslink) information

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Hi guys, I was just looking for a bit of information about the Optical Audio output on my girlfriends Samsung PS50C6900 TV.

My current knowlege isn't amazing when it comes to DIY audio, I know a fair bit about pro-audio, in regards of crossovers, DSP, amps etc. So am able to grasp most concepts but am very keen on learning what I have to, to make this a successfull project.

If I could just give a bit of background information about what I'm wanting to do. I'm purchasing a pair of JBL 8340 cinema speakers from a friend of mine and I'm wanting to use them as speakers for my girlfriends TV, in stereo. My initial idea of how I was going to go about this is go from the optical out (there is a headphone out I could use as I am going to be getting a small chip amp but I like a challenge and it's all a learning curve also) to an analogue-digital audio converter, connect that to a Hifimediy T1 alps TK2050 chip amp (my friend has used some of their amps before and recommended them) and then from there to the JBL's.

Future plan is to incorperate a seperate sub and an active crossover but for now would be relying on the JBL's internal crossover's.

So what I'm wanting to know is:

1. Is there any specific reason why I should not do this, i.e. it doesn't work like this or whatever.

2. If I do it like this, i.e. using the optical out, should I perhaps look at another amp instead that has optical input or maybe a pre-amp with optical in.

3. May sound like a silly question (it does in my head) but you don't learn without asking, what frequency range would be put out from the Optical output, would I need any filtering ? Lowcut perhaps ?

4. Would I get any feedback from anywhere in the signal chain ? If anything I'd think possible from the converter ?

Sorry if any of this information has been outlined elsewhere, I have had a look through a lot of the other sections but couldn't find anything. And would rather ask people that would give me defined answer to my questions. As I've said, I'm very keen in learning new things, very interested in sound in general, have my own soundsytem (PA sized) and love anything DIY and technical.

Thanks,

Myles.
 
Or can someone point me in the right direction of where I can find out what I'm looking to find out ? I appreciate this may be all very basic stuff for most people on here, but I'm new to all this and don't wanna spend out money on bits and pieces and it not work.

Also for anyone thinking that I'm over complicating things, I do like this stuff and would like to see this idea work, also paves the way for future projects.

Thanks,

Myles.
 
There may be no volume control on the optical out, if it's intended to be plugged into an AVR or pre/processor. Check the settings on the TV. It's convenient to be able to use the Volume and mute buttons on the TV remote. You're probably better off using the headphone or line level audio output. Usually the line level outputs are controlled by the TV volume control, but not always.

If you do go ahead with using the digital out, there are readymade DACs on eBay for under $20 shipped. Try searching on digital audio converter optical.

If you check local classified ads, thrift stores and pawn shops you may be able to pick up a complete AVR (audio video receiver) with digital inputs for well under $50. Mine cost $20, but I had to spend another $15 for a remote. I'd hesitate to spend much more, since in the long run you're better off with a more recent AVR that supports HDMI audio. Another advantage of an AVR is that the receiver will have a built-in subwoofer crossover, when you're ready to add the sub. Normally an AVR will have flexible "bass management" that can be configured according to whether you have big or small speakers, and whether there's a subwoofer connected, so the bass won't get lost if you don't have the sub yet. I say "normally" because low end home-theater-in-a-box hardware probably won't have those choices. Proper AVRs can also be configured for "phantom center" so if you watch movies from Dolby Digital DVDs with only two front speakers, the dialogue won't get lost.

Another possibility in thrift shopping is to spot a Dolby Digital processor which was intended to be used with "digital ready" AVRs that had line level 5.1 inputs. The Technics SH-AC500D came with a remote control for volume and input selection, so if you add external amps you've got a fine "digital preamp". They're not extremely common, but I have seen one in the flesh in a thrift store. There were similar boxes from other brands, but AFAIK only Technics produced one with a DTS decoder. After that, digital AVRs became the rule, and digital pre/pros moved upscale for folks with the money for separate amps. (One caveat with the SH-AC500D is that the DTS mode did not implement the normal bass management and phantom center features. I resorted to using an external DIY analog crossover that summed C and S into the L and R channels.)
 
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Thanks for the reply dangus, had a check at the headphone line. The remote control does handle volume up and down and mute, so yeah is quite handy.

Haven't got a DAC yet, think I'll just use the headphone out for now, it means I only really have to buy the amps/psu's. It'll save money this way.

Also made the decision to go through an active crossover. I'm going to be building a sub box for it, so can just have left and right for the JBL's and mono sum the bass.

Think I've got everything I need to know to be able to move forward.

Thanks,

Myles.
 
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