vintageaxeman

Question re: Digital outputs from CD players....

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Super Wammer

Question re: Digital outputs from CD players....

This is actually specifically a question to do with upsampling CD players.

The output from a Redbook CD laser is at 44.1 16 bit.

Some CD players have an upsampling or conversion chip which changes the signal to 96kHz/24 bit or 192kHz/24 bit before the DAC, and then it is fed to the analogue output stages.

My question concerns the digital output socket of such players. Arcam, Astin Trew, etc, etc.

I had always been under the assumption that ALL CD players put out a 44.1kHz signal through their digital output socket. 

Am I wrong?

Or do some CD Players actually send an upsampled 96 or 192kHz/24 bit signal to their digital SPDIF output socket?

(This is a quote from Arcam's website re their Wolfson Multi Dacs:  "An Analog Devices AD1896 second generation asynchronous sample rate converter is used to upsample the incoming16bit, 44.1kS/sec CD data stream to a 24 bit signal at a rate of 192 kS/sec, which is then fed to the left and right DACs.")

So in most cases, where is the digital output socket connected? Almost straight to the cd drive itself? Or after the upsampling chip? Or to the DAC itself?

help, please!

Edited by vintageaxeman

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I have been lead to believe that some players like the Philips cd723 are not bit perfect, but I would imagine most are.

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My CD player can output 44.1kHz, 88.2kHz or 176.4kHz depending on which type of digital output you use.

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If the cd player has an spdif specified digital out phono socket then the output will be sony/phillips digital interface which will be red book.  

I am not sure but provided your DAC is capable of resolving up to 24 bit 192khz you should not have a problem with most if not all cd digital outputs.

I have no idea of the outputs of devices other than a £5 dac from china sorts out the optical output from my TV to provide analogue input to my preamp and my cambridge dacmagic (the one that goes up to 192) works a treat with my HB burnit pro and Marantz 6004 cd players.  You might ask why I use a cheap dac on the tv - that is because i already had analogue wires run from the pre to the tv and when the new tv only had a digital out I did not want to try and then wire in a 20 foot optical cable.

There may be some cd players that feed an upsampled signal but as said if the socket is marked spdif then it will be a red book signal.

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Super Wammer
3 hours ago, Blackmetalboon said:

My CD player can output 44.1kHz, 88.2kHz or 176.4kHz depending on which type of digital output you use.

Can you explain a bit more please? Thank you.

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Super Wammer

I should have made my question clearer and shorter. Sorry!

what I am trying to find out is:

Do spdif digital outputs on integrated cd players always put out 44.1/16?

Or, in the case of cd players with internal  upsampling chips, do their spdif output sockets actually put out those higher rates, or are the 96/24 or 192/24 only used as part of the internal circuitry en-route to the cd player’s analogue stage?

Anyone know for sure?

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15 minutes ago, vintageaxeman said:

Can you explain a bit more please? Thank you.

My CD player (Chord Electronics Red Reference MKIII) upsamples to the three above frequencies which are user selectable. The three digital outputs (Toslink, S/PDIF and AES/EBU) are limited to 88.2kHz unless using the “Chord-centric” dual data mode, which allows up sampling to 176kHz, which in my CD players case requires the use of two AES/EBU cables to connect to a compatible DAC. 

I think you've asked a very good question as I’ve never really thought about it before. 

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Super Wammer

I don’t know for sure, but had always assumed 16/44.1 was the standard output.  Anyone using an external DAC should know, if they have a display.

I recognise that a few specialist products like the Chord mentioned above, can do other things! 

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Moderator

My dCS upsamples internally (switchable) but the S/PDIF output is tapped off before that so it's always 16/44.

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Super Wammer
9 minutes ago, Blackmetalboon said:

My CD player (Chord Electronics Red Reference MKIII) upsamples to the three above frequencies which are user selectable. The three digital outputs (Toslink, S/PDIF and AES/EBU) are limited to 88.2kHz unless using the “Chord-centric” dual data mode, which allows up sampling to 176kHz, which in my CD players case requires the use of two AES/EBU cables to connect to a compatible DAC. 

I think you've asked a very good question as I’ve never really thought about it before. 

That is useful to know. Thank you!  The reason I asked is because I have a couple of midrange CD players which include upsampling to 96 or 192.

However, I also have a PS Audio DAC which upsamples to 96 or 192. The PS unit doesn't have a 'screen'so I cannot discover what frequency the incoming signal is.

And I didn't know if, by using one of these players connected via SPDIF to the PS Audio unit, that the PS unit would be genuinely upsampling from a 44.1 output, or whether the upsampling process was actually unnecessarily being repeated to no advantage.

I do find it difficult to explain this!

Edited by vintageaxeman

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Super Wammer
4 minutes ago, meninblack said:

My dCS upsamples internally (switchable) but the S/PDIF output is tapped off before that so it's always 16/44.

OK, got that. Thank you. Is it a Verdi or a P8i or what?

Edited by vintageaxeman

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Super Wammer
8 minutes ago, Nopiano said:

I don’t know for sure, but had always assumed 16/44.1 was the standard output.  Anyone using an external DAC should know, if they have a display.

I recognise that a few specialist products like the Chord mentioned above, can do other things! 

Thanks Nopiano. That is useful. I have three DACs....only one in use....but none of them have a screen....

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2 minutes ago, vintageaxeman said:

OK, got that. Thank you. Is it a Verdi or a P8i or what?

It's a P8i MkII, so with the Esoteric mech but the most basic version of the dCS DAC.  I use it with a Victor XP-DA999 because it sounds better.

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It’s a bit like upscaling on a DVD. Having said that, CD players can only process red book std being 16/44.1 regardless of information being sent to the DAC internally. If CD players have a digital in that is reading 192/24 say from a streaming service then it is possible if the inbuilt DAC has the ability.

Red Book is what it is 16/44.1

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I am not an expert on this but i do know that sacd players don`t output dsd from digital output . which is a pain as i have to go direct from the analogue outputs rather than my dac 

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