Hi I'm new here and have searched for my problem. It's probably been covered before so please post a link to the topic if this is a repeat topic.

I have recently purchased a philips lcd tv and use the coaxial digital output to connect to my kenwood digital amp.

The problem is that the sound stops after a random period of time. If I turn the amp off or just change to say the radio and back to the digital connection the sound comes back. If I change the tv channel and back again this also brings the sound back.

It appears to happen on the tv channels that broadcast dolby and I don't think it has occured on the channels that broadcast in mpeg sound. Not certain on this though.

I have previously been using a dvd player using an optical cable connected directly to the amp and haven't experienced the problem.

With the dvd connected via coaxial through the tv and passed through to the amp I also get the problem.

So I was thinking it may be a cable issue causing the sound to cut out. I don't get any popping in the audio at all, it just mutes and never comes back unless I do what I said above.

I am using what I believe is a video 75ohm rca coaxial. I don't really want to buy a proper coaxial digital cable and find out it was wasted money.

I will try the dvd directly to the amp using coaxial but won't have the time to sit down and wait to see if the problem happens for a day or two.

Thanks for any help or suggestions you can give.

I have recently purchased a philips lcd tv and use the coaxial digital output to connect to my kenwood digital amp.

With the dvd connected via coaxial through the tv and passed through to the amp I also get the problem.

Do you mean kenwood receiver? Why would you run a digital connection to your TV first?

Yes it's a kenwood receiver.

The reason I run the dvd via digital coaxial through the tv and then to the receiever is so when I change the tv to the dvd input I don't have to change the input on the reciever as well. TV and dvd sound go through the "video 2" coaxial digital input on the reciever rather than different inputs.

I realise this is increasing the connections and cable length but this doesn't appear to be the problem as the tv sound output goes directly to the receiever and this seems to be where the problem lies.

I have tried using a different set of rca leads (normal audio rca's that I use to use for analog sound) but they both seem to cut the sound out randomly.

I don't think the amp is going into a sleep mode or anything like that because I didn't have this problem with the optical connection I was using before direct from the dvd player.

I have tried using a different set of rca leads (normal audio rca's that I use to use for analog sound) but they both seem to cut the sound out randomly.

Digital audio requires 75ohm coax cabling. Analog audio does not, and the cables you have may not be 75ohm coax. If they're not coax cables, say twisted pair, then they certainly aren't 75ohm. Try a proper 75ohm cable and see if this goes away. Those analog audio cables may be 75ohm, but unless they're labeled as such you don't really have any way of knowing. A proper cable is super cheap anyway, so it's not a big deal to test this first before assuming something much more expensive is at fault...

Does your TV pass multichannel audio from external components out the digital port? Very few do. With nearly all sets, you will only get 5.1 audio from the TV's internal tuner. Everything else gets downmixed to stereo.

I suggest you (A) buy the proper optical or coax cables. They cost about $3 from monoprice. Monoprice is an AVS Forum sponsor and there's a link at the top of the page. (B) Connect the audio from your components to the receiver, not the TV. Televisions are not designed to be audio switchers. (C) Get a Harmony remote. Harmony is easy to setup and even easier to operate. Push one button and all of your gear powers up and switches to the correct inputs for whatever you want to do. You can pick one up for less than $100.

Thanks for all yout help. I had thought about the harmony remotes so may go down that path later.

I think the tv passes through multichannel. I only set the tv up yesterday so only put a dvd on to make sure everything worked. I think I remember the kenwood reciever saying dolby digital with the multi channel display on but I will conform that later.

Looks like it's worth my time and money buying proper digital coaxial cables due to the responses here.

I live in Australia so I will probably purchase them locally. That site gives me a good idea how expensive some of the other brands of cables are so thanks for the link.

Just an update.

The tv does pass through multi channel digital.

I have changed the kenwood receiver to digital rather than auto detect. I now get brief drop outs so I'm fairly confident it is the cable causing the drop outs. I will go out and get a decent coaxial cable so the dropouts don't occur and I can turn my receiver back to auto so the mpeg broadcasting tv channels have sound.

I'll keep you all posted.

The tv does pass through multi channel digital.


It does? Wow. What model is that? (Most TVs don't do this.)

BTW, a subwoofer cable also works for digital coaxial.

Thanks for th info. I may try my sub cable just for verification.

The tv model is Phillips 32PFL7532D/79. 32 inch lcd. Happy with it. The pictures nice and the picture setup makes it easy to get prefered picture settings, but it's no way a high end tv.

I have found no reference to it being capable but it definately does output via the internal tuner and pass through multi channel digital.

I know it passses dolby 5.1, haven't tested dts though or any other format of digital audio.

Any RCA plug cable with a 75ohm rating works. That includes digital coaxial, most sub cables, and composite (yellow RCA plug) video cables.

In fact, Monoprice markets the same cable as all three.


I have found no reference to it being capable but it definately does output via the internal tuner and pass through multi channel digital.

So it lights up a Dolby Digital indicator on the receiver or something?

Yes it does. With 2 channel dolby it shows two speakers on receivers display and dolby pro logic, but when on multi channel tv broadcast and also dvd it shows the 5 speakers, sub and dolby digital rather than dolby prologic.

The receievr is a 6.1 channel but I don't have anything that has 6.1 or 7.1 channel to see if it passes more than 5.1 channels.

Yes it does. With 2 channel dolby it shows two speakers on receivers display and dolby pro logic, but when on multi channel tv broadcast and also dvd it shows the 5 speakers, sub and dolby digital rather than dolby prologic.

That's kind of cool. A lot of people have audio routed through the TV and are disappointed to learn they only get stereo.


The receievr is a 6.1 channel but I don't have anything that has 6.1 or 7.1 channel to see if it passes more than 5.1 channels.

There are some DVDs with 6.1. 7.1 is getting into the realm of Blu-Ray.

(Most TVs don't do this.)some do

Yeah, apparently. I'd just never heard of a specific model that did.

Plenty of threads about models that DON'T. Especially in this forum.

I bought a proper digital audio 75ohm lead. It's a dick smith titanium series.

I still get cut outs. Hasn't really changed much from what I can tell. I have diagnosed that the sound cut outs and stays off when in auto detect mode but will come back on after a cut out when set to digital mode.

It appears like turning on lights can cause the sound to cut out which makes me think it may be an interference problem. But it's not always because of lights though. Whether the noise is through the lead or whether it's the amplifier getting the noise I am not sure and can't think how to diagnose this. I may run the amp of another phase in the house.

Any other suggestions?????

I may look into getting a coaxial to optical converter if they aren't too expensive and run digital through the optical lead I already have.