AC-3 is exactly the same as Dolby Digital, Right?

[Seth=L]

So, I was showing a friend of mine my find (Sony DVP-S7000) and we where doing a side by side comparison of his player and mine. It outputs PCM just fine but when I set it to "AC-3 Digital" we get no output. We tried direct on the receiver (Onkyo TX-DS787) as well as regular input. We used Toslink and it did work for PCM as mentioned already.

From what I have read and understand there is no difference between AC-3 and Dolby Digital, Dolby just though that they needed to give it a better name. RF is another story entirely of course, and almost virtually exclusive to Laser Disc, so obviously not part of the issue. We ruled out the receiver as the problem, it works fine with the other DVD player.

So, there is something wrong with the player, or AC-3 is a different animal, or I am missing something (I have scanned through the settings to find the culprit for this error.)

(I have not tried connecting this DVD player via SPDIF to any other receiver, DAC, or processor.)

If there are any details you need to diagnose the problem just ask and I will provide the appropriate information sometime later.

Thanks in advance for any help.

 

[no. 5]

Yep, AC-3 is the 'working title' of Dolby Digital.

history

 

[mtrycrafts]

So, I was showing a friend of mine my find (Sony DVP-S7000) and we where doing a side by side comparison of his player and mine. It outputs PCM just fine but when I set it to "AC-3 Digital" we get no output. We tried direct on the receiver (Onkyo TX-DS787) as well as regular input. We used Toslink and it did work for PCM as mentioned already.

From what I have read and understand there is no difference between AC-3 and Dolby Digital, Dolby just though that they needed to give it a better name. RF is another story entirely of course, and almost virtually exclusive to Laser Disc, so obviously not part of the issue. We ruled out the receiver as the problem, it works fine with the other DVD player.

So, there is something wrong with the player, or AC-3 is a different animal, or I am missing something (I have scanned through the settings to find the culprit for this error.)

(I have not tried connecting this DVD player via SPDIF to any other receiver, DAC, or processor.)

If there are any details you need to diagnose the problem just ask and I will provide the appropriate information sometime later.

Thanks in advance for any help.

AC3=DD.

AC3 was the early name used, Audio Code 3, 3rd generation of the code.

That 7000 was a robust player, so it may be something we are overlooking here.

 

[Seth=L]

Ok, so we have ruled out AC-3 being different in any way from Dolby Digital, which doesn't get me much closer to the answer because I was already pretty much convinced that AC-3 was just the name of Dolby Digital before they changed the name. I hope that I am missing something on the player, but I don't think I am. The set-up features are fairly elementry. So until I find something that caused it I will assume there is something wrong with the player.

 

[Adam]

Seth=L, I doubt that this will be it because you know a lot...but is it set up to output bitstream for AC-3?

 

[Dolby CP-200]

Last I heard the terms can be rather confusing Dolby SR-D AC-3 Dolby digital.

 

[Johnd]

Many ac-3 players of that vintage (late '90's) did not have processors to decode the signal...an external processor was necessary.

Case in point: my Denon DVD-5000. I can play dd through analog cables, but not through optical. Maybe that helps.

 

[Adam]

Many ac-3 players of that vintage (late '90's) did not have processors to decode the signal...an external processor was necessary.

Case in point: my Denon DVD-5000. I can play dd through analog cables, but not through optical. Maybe that helps.

John, that confuses me. If the player can't decode the signal, wouldn't it then be able to output the bitstream through the optical line but not be able to output an analog signal? Thanks.

 

[Seth=L]

Maybe I should try the coaxial output instead of the toslink.

Adam,

Yes, it is set correctly (AC-3 Digital and PCM are my only options)

 

[Adam]

Maybe I should try the coaxial output instead of the toslink.

I thought of suggesting that, but forgot about it during the walk from the bedroom to the computer. Too early in the morning at the time.

 

[Johnd]

John, that confuses me. If the player can't decode the signal, wouldn't it then be able to output the bitstream through the optical line but not be able to output an analog signal? Thanks.

Sorry. Let me clarify. I can only play dd by sending the signal to my receiver, and allowing the receiver's processor to decode the signal. An optical (or digital) cable prevents any downstream decoding.

 

[Adam]

Sorry. Let me clarify. I can only play dd by sending the signal to my receiver, and allowing the receiver's processor to decode the signal. An optical (or digital) cable prevents any downstream decoding.

Okay, I'm off to make more coffee to get my brain started. But, that still doesn't sound right to me. I completely understand the notion that a DVD player wouldn't have a built-in decoder (been there, done that). However, I thought that the digital cables are the only ones that DO allow downstream decoding.

 

[no. 5]

An optical (or digital) cable prevents any downstream decoding.

The only way anything other than the DVD player could decode Dolby Digital is if it had access to the RAW bitstream from the disc, and the only way to get the RAW bitstream out of the player is to use a digital connection (i.e. S/PDIF).

 

[Johnd]

Okay, I'm off to make more coffee to get my brain started. But, that still doesn't sound right to me. I completely understand the notion that a DVD player wouldn't have a built-in decoder (been there, done that). However, I thought that the digital cables are the only ones that DO allow downstream decoding.

No, no. I'm the one that needs coffee...a pot of it. Scratch most of what I said.

The issue may simply be that your player lacks the processor...so it becomes a cabling issue.

Adam, good catch. I'm off to get some coffee!

 

[Johnd]

The only way anything other than the DVD player could decode Dolby Digital is if it had access to the RAW bitstream from the disc, and the only way to get the RAW bitstream out of the player is to use a digital connection (i.e. S/PDIF).

Yes, yes, no. 5. Just made the catch. Where in Wisconsin? I'm near brew city.

 

[no. 5]

A bit north, in Door County.

 

[Dolby CP-200]

Many ac-3 players of that vintage (late '90's) did not have processors to decode the signal...an external processor was necessary.

Case in point: my Denon DVD-5000. I can play dd through analog cables, but not through optical. Maybe that helps.

Wasn’t it a (Dolby AC-3 demodulator) I have many laserdiscs still but no modification to the laserdisc players I own two I think the (Dolby AC-3 demodulator) is still obtainable thou a bit pricy on some sites for a technology that is about 10 to 17 years old.

 

[Johnd]

A bit north, in Door County.

Sweeeet. Nice area...away from all the hubbub.

 

[Johnd]

Wasn’t it a (Dolby AC-3 demodulator) I have many laserdiscs still but no modification to the laserdisc players I own two I think the (Dolby AC-3 demodulator) is still obtainable thou a bit pricy on some sites for a technology that is about 10 to 17 years old.

Perhaps. But any processor, as in an av receiver, will decode the signal on his player. Laser disc? You're a dinosaur! But so am I. I still have my Sony El Casette player from 1979.

 

[no. 5]

Nice area...away from all the hubbub.

Except for this time of year.