2. music
  3. 182775-87347

Learned something new today and it isn't good.

I have been in this crazy hobby for over five decades and thought I knew most of the basic information regarding audio quality.

That was before this morning.

Today I learned about the practise of applying "pre-emphasis" to CDs that was around during the late '70's and early '80's. Apparently this practise was developed as a way of reducing the signal to noise in digital audio. The problem is this was a two-part process and required the CD player to have a "de-emphasis" capability to allow the disk to play properly. Without the application of de-emphasis, cd's would sound "bright".

My question would be, "Does everyone else know about this?"

If you do, "How do you deal with it?"

I still listen to CDs and this is not something I need in my life.

128x128tony1954
onhwy61's avatar
onhwy61
5,143 posts
 

@tony1954 does your CD player have the de-emphasis circuitry?  If it doesn't, then those CDs will sound a little bit bright.

tony1954's avatar
tony1954 OP
898 posts
 

@onhwy61 

I have been trying to find out, but so far no luck.

I have the Cambridge Audio CXC transport.

 

erik_squires
15,798 posts
 

Apparently this practise was developed as a way of reducing the signal to noise in digital audio.

 

Well, it was to INCREASE the signal to noise.  As I recall it had something to do with the early anti-aliasing filters not being great.  AFAIK, any CD player should automatically detect and enable/disable the matching de-emphasis as should most  audio playback systems.  However it's imperfect.  According to this, it's not on a lot of CD's so maybe you don't care??

https://studio-nibble.com/cd/index.php?title=Pre-emphasis_%28release_list%29

kijanki's avatar
kijanki
4,398 posts
 

Pre-emphasis was a way to reduce tape noise from analog recordings.  When studios started recording digital there is no use for it.  CD contains pre-emphasis bit engaging de-emphasis built into every player automatically.

drmuso's avatar
drmuso
76 posts
 

I have an old tube DAC that has de-emphasis circuitry and an indicator light when a CD has pre-emphasis.  Only a few classical CDs in my collection made this indicator light go on; maybe I don't listen to those anymore, but I haven't been troubled that my subsequent DACs lacked this circuitry.

If you think you want a DAC with the de-emphasis circuitry, I'd be willing to sell my Anodyne ATAS.  It was working fine last time I used it.  When I bought it in the 1990s, it sounded better than a well-reviewed Wadia DAC I compared it to in my system.  The ATAS cost $3000 then.  I've intended to put it up for sale, but just haven't gotten around to it.  IIRC, it only goes up to 48kHz, so it won't work for today's high-res files.  But it will give CDs some nice tube warmth. 

More to discover