HydrogenAudio

CD-R and Audio Hardware => CD Hardware/Software => Topic started by: mccarthyk on 2013-01-28 07:01:09

Title: 24bit CD Players
Post by: mccarthyk on 2013-01-28 07:01:09
CD players seem pretty outdated nowadays.  I even replaced my laptop's CD drive for an SSD - because I download nearly all of my music online, and when I want to rip a CD I just plug a drive into my eSATA port.  But I was looking for a CD drive to complete my new stereo setup - which I don't think I am even going to get because I have a turntable for my vinyls and my laptop for everything else...

However, I found that there are a lot of 24bit CD players on ebay that sell for 2 to 5 thousand dollars!  As far as I was aware CDs are physically 16bit storage devices.  Am I wrong?  Are CDs actually 24 bit, or are these multi thousand dollar CD players just complete gimickes?
Title: 24bit CD Players
Post by: Kohlrabi on 2013-01-28 07:42:32
Snake oil for the gullible.
Title: 24bit CD Players
Post by: Wombat on 2013-01-28 11:57:35
There may be an advantage if the CD Player is used with a build in volume control or if it applies things like de-emphasis. 24bit precision can help here to have enough headroom.
Title: 24bit CD Players
Post by: skamp on 2013-01-28 12:00:25
Also, HDCD decodes to 20/24 bit.
Title: 24bit CD Players
Post by: db1989 on 2013-01-28 12:07:23
But neither of these hypothetical benefits warrant a price in the range of hundreds of pounds, never mind thousands, especially not nowadays.
Title: 24bit CD Players
Post by: 2Bdecided on 2013-01-28 12:14:54
I don't think anyone has made a strictly 16-bit only 44.1kHz only CD player for decades.

Once you oversample to allow digital anti-alias (anti-image) filtering, you no longer have the original "bits" anyway. You need a DAC that has a sufficiently low noise floor and linearity to reproduce the signal cleanly. That could have any number of bits, from 1 to 24 (or, in marketing speak, even more  ). A DAC that failed on the noise and/or linearity requirement could also have any number of bits.

Cheers,
David.
Title: 24bit CD Players
Post by: Arnold B. Krueger on 2013-01-28 15:54:29
CD players seem pretty outdated nowadays.  I even replaced my laptop's CD drive for an SSD - because I download nearly all of my music online, and when I want to rip a CD I just plug a drive into my eSATA port.  But I was looking for a CD drive to complete my new stereo setup - which I don't think I am even going to get because I have a turntable for my vinyls and my laptop for everything else...

However, I found that there are a lot of 24bit CD players on ebay that sell for 2 to 5 thousand dollars!  As far as I was aware CDs are physically 16bit storage devices.  Am I wrong?  Are CDs actually 24 bit, or are these multi thousand dollar CD players just complete gimickes?


Any music player that goes for over $200 is IMO very, very hard to justify.  You can get fine BD players with web and LAN access for under $100.

Given that CDs are and will always be 16  bit entities, I don't even know what 24 bit CD player means.
Title: 24bit CD Players
Post by: Arnold B. Krueger on 2013-01-28 16:02:00
There may be an advantage if the CD Player is used with a build in volume control or if it applies things like de-emphasis. 24bit precision can help here to have enough headroom.


The Cirrus CS 3308-3318 provides a ready analog-domain solution for a music player volume control:

http://www.cirrus.com/en/products/volume_controls.html (http://www.cirrus.com/en/products/volume_controls.html)

Title: 24bit CD Players
Post by: Wombat on 2013-01-28 16:44:01
The Cirrus CS 3308-3318 provides a ready analog-domain solution for a music player volume control:
http://www.cirrus.com/en/products/volume_controls.html (http://www.cirrus.com/en/products/volume_controls.html)

Why use another chip when recent DACs have a build in digital volume control?
http://hifiduino.wordpress.com/2012/01/31/...er-than-analog/ (http://hifiduino.wordpress.com/2012/01/31/the-sabre-dac-digital-volume-control-better-than-analog/)
Title: 24bit CD Players
Post by: LithosZA on 2013-01-28 17:13:14
Just for interest sake, what benefit does a volume control give at other levels of the audio chain (like at the DAC)?
I always just change the volume right at the end of the audio chain; usually at the amp.
Title: 24bit CD Players
Post by: Wombat on 2013-01-28 18:31:49
Just for interest sake, what benefit does a volume control give at other levels of the audio chain (like at the DAC)?
I always just change the volume right at the end of the audio chain; usually at the amp.

Imagine your amp has no volume control that can be changed over remote. Use the build in one then.
In my case i didnĀ“t use a pre-amp since the second CD-Player generation. I always feeded power-amps directly over the exit of a CD-Player and later a DAC.
Now i use the build in 24bit volume of my Network Player feeding 2 monoblocks. No pre-amp needed.
You see i for example did use volume control at the source for a while now.
Title: 24bit CD Players
Post by: Arnold B. Krueger on 2013-01-28 18:51:18
The Cirrus CS 3308-3318 provides a ready analog-domain solution for a music player volume control:
http://www.cirrus.com/en/products/volume_controls.html (http://www.cirrus.com/en/products/volume_controls.html)

Why use another chip when recent DACs have a build in digital volume control?
http://hifiduino.wordpress.com/2012/01/31/...er-than-analog/ (http://hifiduino.wordpress.com/2012/01/31/the-sabre-dac-digital-volume-control-better-than-analog/)


The solution I mentioned is a pure analog domain solution from the standpoint of the audio signal.

For example the CS 3318 handles 8 channels with 127 dB dynamic range and is particularly cost effective in AVRs.  You can match its performance with a digital domain solution but not for anything like the price per channel.  It is commonly used in AVRs following DAC chips with far more humble specs (e.g 100 dB or less) for dynamic range, while providing a cost-effective overall system with equal or better dynamic at low listening levels as compared to all-digital solutions.

It seems a bit backward but current production AVRs generally implement the volume control and most signal switching in the analog domain, while running the DSP at levels close to FS.
Title: 24bit CD Players
Post by: Arnold B. Krueger on 2013-01-28 18:53:03
Just for interest sake, what benefit does a volume control give at other levels of the audio chain (like at the DAC)?
I always just change the volume right at the end of the audio chain; usually at the amp.


That is pretty much current generally accepted practice - put the main volume control at the input to the power amp.