TV sound d/a conversion

I had the same with my most recent TV. I can't recall which model of opto DAC I got but I did find one that could be powered directly by a USB socket on the TV to avoid yet another wall wart syndrome.

I'd caution against the very cheapest and would have preferred mine if it had produced true line out spec signals when compared to my existing signal sources. The TV opto DAC is about 6dB quieter than everything else connected to the main power amp with the one I bought. YMMV

The DAC I used for this seems to work OK.

Jim

Nice TV, why not investigate the bits to do surround sound?

Lots of 5.1 dolby digital receivers on eBay, folks get rid of them cheaply (< £50) the ones that don't have HDMI sockets.

I first used a pro unit I had lying around - had inputs for all the common digital standards and balanced and unbalanced outputs. Snag with that - other than its size - was it booted up to the AES input, so had to be toggled to Toslink, or left powered up all the time. It also had a nasty AC wall wart which induced hum on the record player/

I bought an el cheapo off Ebay - looked the same as the cheaper one you've listed. Well under a tenner. Can't really say it sounded any different. Except the analogue output from it was very low - compared to every other source to my Hi-Fi. I think you'll find both of those you've listed are the same in that way. Of course that may not matter to you.

I was going to build it in to a unit with adjustable gain.

Then decided I might as well use the posh mini-disc I have in the system - not much used as such, but has a Toslink input with adjustable gain.

The cheap one is likely to be made in a secondary factory in China with minimal quality control from components which are either classed as seconds or recycled. You may get a very good one but you are just as likely to get a poor one. There is no power supply with the cheap product.

The quality control of the Lindy product will be much more consistent as they need to protect their reputation and have had good reviews in the HiFi press despite being relatively cheap. (Richer Sounds do a similar product - the CYP AUD3-192)

Some years ago when I got a Samsung monitor TV I was going to get that Lindy DAC but realised that I'd also find use for one that also allowed digital audio via USB and a headphone output with volume control so looked at the more expensive Lindy one:

However I found that Maplin did the same product without the Lindy branding at a lower price - they still do it (although the price is quite a bit more than I paid):

It's worked faultlessly and the sound is good.

Alan

My guess is that might be difficult with a 5 volt supply.

TV sound generally sticks to the EBU standard of never peaking above -10 dBFS. Just have a listen to commercial radio via FreeView to see what it can peak to on that system.

If the output is such that it is clean at 0dBFS, it might well not handle peaks with an additional 10dB of gain - which it would need to match other sources, when just used with ordinary TV broadcast sound.

Because it's a five minute wonder - like 3D? ;-)

Or more likely because they don't use the surround side.

I'd solder wires to the speaker terminals. Sod digital.

Nah, OK, some films do have terrible surround soundtracks, but some are outstanding. Depends if it's a television or a home cinema interest. The size of that screen to me is crying out for the latter, but each to their own :)

Training vs. Benefits.

Following the instruction book is a block to many, these things are complex!

Does it have an earphone socket? Brian

It may well have. But frequently the cable will then show - not something you want for a permanent installation. And the quality may not be as good either.

No headphone socket, I might have tried it otherwise.

Chris

You wouldn't want to tap of the speakers like someone's suggested the Earth on the TV chassis is anything but. Optical link does provide excellent isolation..

I've done it from headphone sockets NP. Earth IS earth pretty much on a modern set..

If only someone did a Toslink adaptor with some makeup gain.

The problem I found was the need for another volume control.

Agreed. A switch to change the DAC reference voltage, would be a good addition.

If DIY, would be trivial for a one off, just find a data sheet for the chip?

FWIW I just used a cheap Velleman/CPC kit for gain and modified it to suit. Easier and quicker then from scratch.

But if you only need variable attenuation, then a pot or some resistors would do.

Jim

I've found the Sennheiser Headphone stereo volume control effective particulalry if one ear is less sensitive than the other.

Alan