I've posted this question to the audio theory, but thought the problem may be with the source too...

I have two setups, one is an Adcom GTP 860 in my main theater, and the other is a cheapo Yamaha in the living room. Both were fed with Samsung MPEG2 HD D* boxes using coaxial, and its been fine for years.

I recently upgraded to the new MPEG4 boxes, which don't have coaxial, so I've had to switch to optical. On the yamaha, totally out of the blue the audio will go away, all except for the LFE channel. I'm not even bringing up the lip sync issues, this is totally losing the audio stream, or having it lose certain channels.

On the Adcom, something similar happens, all the audio disappears, although it still senses a dolby digital bit stream present. When it comes back it causes such a huge pop that my Crown amps go into protection. When its out, changing channels doesn't do anything. I also tried running the optical through a converter/switch that outputs over coaxial, and I still have problems with dropouts and pops. Seems like something is wrong with the optical audio stream?

Has anyone else had problems like these on the new MPEG4 box??

Which model MPEG4 boxes?

I've posted this question to the audio theory, but thought the problem may be with the source too...

I have two setups, one is an Adcom GTP 860 in my main theater, and the other is a cheapo Yamaha in the living room. Both were fed with Samsung MPEG2 HD D* boxes using coaxial, and its been fine for years.

I recently upgraded to the new MPEG4 boxes, which don't have coaxial, so I've had to switch to optical. On the yamaha, totally out of the blue the audio will go away, all except for the LFE channel. I'm not even bringing up the lip sync issues, this is totally losing the audio stream, or having it lose certain channels.

On the Adcom, something similar happens, all the audio disappears, although it still senses a dolby digital bit stream present. When it comes back it causes such a huge pop that my Crown amps go into protection. When its out, changing channels doesn't do anything. I also tried running the optical through a converter/switch that outputs over coaxial, and I still have problems with dropouts and pops. Seems like something is wrong with the optical audio stream?

Has anyone else had problems like these on the new MPEG4 box??

My digital optical connection on an H21 has been trouble-free. Are you very sure that the optical connection is secure at both ends? Not only do the connectors only fit in the terminal one way but they have to snap in place to be secure. I vaguely recall having a problem months ago - not involving current equipment - and discovered that I hadn't really managed to get the optical cable snapped into the terminal socket. Let's hope that's all it is.

Dana

I have a digital coax connection between my DVD player and my amplifier - and I realised I was getting sound drop-outs caused by my central heating boiler switching on... (I was using standard cheap RCA audio cable - probably not screened!) Do you have anything like a freezer, fridge, central heating system that is switching in correlation with your audio drop-outs?

I have a digital coax connection between my DVD player and my amplifier - and I realised I was getting sound drop-outs caused by my central heating boiler switching on... (I was using standard cheap RCA audio cable - probably not screened!) Do you have anything like a freezer, fridge, central heating system that is switching in correlation with your audio drop-outs?

These would be logical sources of interference - if he was using digital coax. But, he says he switched to digital optical cable so he can discount electrical interference.

Dana