I first ran into this when a new cable company came to town and their cable box only output digital when on the premium channels. On basic cable channels the digital output went dead and only the analog output worked.

That would have been ok with an Integra receiver that I install, but the client had a Harman Kardon (I do not like those things, and like their remotes even less) that would not sense the digital drop and go to analog in - you had to navigate thru menus to get back to analog. Bad!

Yesterday, a new twist. Cust has new Mits DLP 52" and everything is great with digital coax out of the TV (has HD tuner built in) to an Integra receiver set to coax 1. Then flipping thru channels there is no sound on some. I couldn't spend enough time to figure the rhyme or reason, but unplugged the coax cable and the sound returned. The receiver was properly sensing the digital stream when there and when I pulled the cable it popped back to analog automatically. But this TV output a digital stream with no audio whatsoever on it! Dolby Digital light is on in the display of the receiver but zero audio. Change channels and it's back.

I'm guessing it is Comcast's fault and not the TV but I can't be sure. Goofs up configuration pretty well - leave the client with analog audio all the time...I left a button to change to another input for digital ins when they are watching movies, but it's not a clean setup.

Anyone run into this?

Yep, We have problems with the Digital optical outputs on teh cable boxes from time warner. They drop out, or are not there. This is usually due to a low quality cable signal. We always use the Coaxial digital because of less drop out. Also the Optical is much lower in volume.

Mike

Sorry Mike I'm pretty sure that his described problem is not related to cable quality.

This has been a problem for several years now. My experince has been that it happens when there is still an SPDIF carrier present but no audio content. Most receivers and processors will lock onto the carrier and are not smart enough to know that there is no audio content present. They do this in an attempt to keep the receiver input locked onto the digital signal and not keep switching back and forth between analog and digital when there is silence. I feel the problem lies in the source unit - that it should always put sound out on the digital output regardless of whether you land on a digital station or an analog station.

You might try going into the set up menu of the cable box and play around with the settings and see if you can have some sort of success. Sometimes setting digital audio to PCM will solve the problem but then you might not get DD 5.1 when landing on a station with that type of stream. If all else fails you might have to resort to only analog cables.

Harman makes receivers that have digital input polling. (others may too, but I know about these.)

In English, selected models allow you to hook up both the digital and analog outputs from your cable box. The system will prioritize to digital and revert to analog if a signal isn't present.

Makes the problem go away.

With all due respect Fred, I doubt it. If the digtial carrier is still present then most receivers wil lock onto it, which I'll bet is Tom's problem. That "lock" will prevent the receiver from switching over to analog. It can't discriminate from a carrier with no audio content to a carrier with audio content. ANd processors can't lock onto only audio content because it would constantly be switching back and forth during quiet passages.

The older HK's will auto sense Digital/analog on Video 2. All the new HK receivers auto sense on all outputs.

Yamaha & Denon have auto sensed for about 5 or more years. Just some of the cheap brand stuff doesn't at this point. Try Video 2.

The HD cable boxes from GI, SA and Motorola seem to have all gone to all digital audio so this a/d problem is slowly diminishing. The newest SD boxes have been going digital as well.

We still attach the analog cables regardless because we send cable music to zone 2. Zone 2 requires an analog signal on most Multiroom receivers.

It's possible the customer has an older box. Call the cable co and get the newer box.

Had similar probs w SA cable box and Rotel. When changing cable channels, audio would revert to analog and receiver had to be cycled on/off to restore digital. Big Problem... customer" paid for digital and by gosh he wanted it". Rotel responded with a software fix, took some time but they were on it as soon as we informed them and even Mike Bartlett (President of Rotel) called to insure client was happy. That folks is SERVICE.

TJG

I agree with Steve. The problem is in the cable box. I have expereinced this with older cable boxes and the newer boxes in my market do not exhibit this. They seem to put digital audio out on all channels.

We have an AVR-630 hooked to a mits dlp via the digital coax and have the same problem. Still enough signal present on the coax to keep the polling feature from working correctly.

Jason

No cable box - Mits TV with HDTV tuner and Cable Card.
Options in setup are SPARSE to say the least.

This one I recall was an AVR7000 vintage. Wouldn't poll.

The Integra in yesterday's system does exactly what you are referring to, but as FP says, it's seeing a carrier that's got no audio on it.

I have the analog cables on there (always).

No cable box; new HDTV using built in tuner

I have not run into this problem in my area with the Motorola cable boxes from Comcast. Probably just reading this post will cause these failures...;)
Most of what I have in the clients homes at this point are the 6200 series using the toslink,if used for video.The older boxes, if they were already online, are connected the the house music system using the analog outputs.