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Discussion Starter #1
I wanted to bounce some ideas off you guys so that I know if I'm understanding things correctly or not. Let's say I compare a CDP to a Blu-ray player listening via digital connection. Theory would say that it should sound the same. I had two units in my room today but the Blu-ray player sounds very different while playing back the same music via digital.

It then dawned on me that perhaps the output voltage between both players are different. I wanted to know that I'm not crazy here - can a different output voltage affect what I hear when listening to music, if I keep the volume levels on my amp the same?
 

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Yes. Recordings sound different at different volume levels. You need to level match with a voltmeter across the speaker terminals.
 

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Maybe it's just a difference in the electronics, DAC's or a bad mood. :)

IMHO, use whatever device sounds best to you.
 

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Coax from Blu-ray to receiver. From CDP, coax to receiver, different input.
A difference in voltages on the coaxial "shouldn't" make any difference - that is not the musical signal.

The music is in the data that is being transferred, 0's and 1's.

Unless the voltage on the coax is so far out of spec that the coaxial receiver can't read the data without error, there should be no difference.

So, if there is a difference, it 'should' lie someplace else. Verify the receiver isn't handling the inputs differently. Verify the BluRay isn't changing the data format.

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Swap the coax at the receiver and see if the 'difference' moves - if yes, something different in the sources.

If no, then something different in the receiver (or your imagination is doing it).

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I have multiple digital sources of different types - Coax, Optical, USB - TV, HDRadio, Cable Box, Roku, CDP, Oppo, PC streams - I don't notice any difference in the character of the different sources, just differences in the material being played.
 

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Discussion Starter #7
A difference in voltages on the coaxial "shouldn't" make any difference - that is not the musical signal.

The music is in the data that is being transferred, 0's and 1's.

Unless the voltage on the coax is so far out of spec that the coaxial receiver can't read the data without error, there should be no difference.

So, if there is a difference, it 'should' lie someplace else. Verify the receiver isn't handling the inputs differently. Verify the BluRay isn't changing the data format.

--

Swap the coax at the receiver and see if the 'difference' moves - if yes, something different in the sources.

If no, then something different in the receiver (or your imagination is doing it).

--

I have multiple digital sources of different types - Coax, Optical, USB - TV, HDRadio, Cable Box, Roku, CDP, Oppo, PC streams - I don't notice any difference in the character of the different sources, just differences in the material being played.
So when can the output voltage affect the volume? Only on the analog outs? Not the digital?
 

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So when can the output voltage affect the volume? Only on the analog outs? Not the digital?

Only on the analog side is the voltage level changed to create volume (loudness) changes.

On the digital side, the voltage level is interpreted as ON or OFF, 0 or 1. There is a threshold voltage that the receiver distinguishes where a 0 or 1 is being signaled. If the voltage is wrong, expect errors in the data, and noise or dropouts in the conversion of the data to an analog waveform.
 

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As for analog voltage output, it's conceivable that different disc players from different technologies/manufacturers/eras could scale their DAC outputs differently.

It's possible that two different digital inputs are scaled differently.

Did you swap input connections and compare again?
 

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As for analog voltage output, it's conceivable that different disc players from different technologies/manufacturers/eras could scale their DAC outputs differently.

It's possible that two different digital inputs are scaled differently.
Measure a few different brands and models and you'll find it's very rare for them to output the same level with the same signal. The only time there was any consistency was early in the CD era when Sony/Phillips set the output levels to 2Vrms single ended but I don't recall any company getting into trouble if they were a bit different. Now, they're all over the place.

Looking at a few random players at Stereopool:
Primare CD32 CDP: 2.07V SE, 4.16V diff
Parasound Halo CDP: 1.97V SE and 3.94 diff.

If you compared these in the same system just switching between inputs, most people would rate the Primare higher because it's fractionally louder by 0.43dB.
 

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Discussion Starter #12
Measure a few different brands and models and you'll find it's very rare for them to output the same level with the same signal. The only time there was any consistency was early in the CD era when Sony/Phillips set the output levels to 2Vrms single ended but I don't recall any company getting into trouble if they were a bit different. Now, they're all over the place.

Looking at a few random players at Stereopool:
Primare CD32 CDP: 2.07V SE, 4.16V diff
Parasound Halo CDP: 1.97V SE and 3.94 diff.

If you compared these in the same system just switching between inputs, most people would rate the Primare higher because it's fractionally louder by 0.43dB.
Are you suggesting that it's possible there may have been volume differences on the digital outputs/inputs between players? I'm perfectly prepared to admit that I imagined a difference as my test was casually done, but if there is a physical explanation then I would love to know.

I'm just trying to rule out any possibilities and I thought that perhaps there might be a volume difference, but I don't have the tools to measure that kind of stuff. Just thought I would ask.
 

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Are you suggesting that it's possible there may have been volume differences on the digital outputs/inputs between players?
Digital I/O such as SPDIF it doesn't matter. The levels in my previous post were the measured L/R analogue outputs.

I'm just trying to rule out any possibilities and I thought that perhaps there might be a volume difference, but I don't have the tools to measure that kind of stuff. Just thought I would ask.
Sorry, I misread the OP. In my test I was assuming analogue outs from both players into a preamp and them switching between them.

I would need to see your test done blind for me to believe there is a difference.
 

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Can jitter in digital components audibly effect the sound that one hears?
If it's really, really bad, far worse than the products on sale today.
Be careful, you might awaken the jitter monkey.
 
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It might be the same music but is it the same master?
If the Blu-ray contains a remastered version in 24/96 it sure will sound different.
Well, it may sound different, not always, and not because it's 24/96.

Don't go down that jitter hole....
 
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