CS4272 noise floor problem - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 21st September 2007, 03:41 PM   #1
2sb18 is offline 2sb18  Canada
diyAudio Member
 
Join Date: Jul 2005
Location: Ottawa, Canada
Question CS4272 noise floor problem

Hi,

I'm using the CS4272 codec to convert to and from digital. I've attached a picture of the noise floor. The red line is the signal going through the analog filters and the CS4272. The black line is just the analog filters. As you'll see, there's a crazy 30dB/octave increase in the noise starting at 10kHz.

I've tried a bunch of stuff, but it seems right now I have a very interesting noise generator instead of a good sounding codec.

I'm posting this in the hopes that someone will see the noise floor graph, remember when they had a similiar problem, and go "oh ya, it was this!"

Any help would be greatly appreciated,

Steve.
Attached Images
File Type: png ns.png (5.6 KB, 159 views)
  Reply With Quote
Old 1st October 2007, 08:52 PM   #2
diyAudio Member
 
Join Date: Nov 2004
Location: Germany
Looks like noise shaping to me. Pretty extreme though - with the CS4382 the increase in noise only starts at 30 kHz, and in the WM8770 this must be beyond 48 kHz. I guess the CS4272 uses a conventional 1-bit DAC, maybe not that fast, and has to do fairly heavy noise shaping to achieve the specified SNR. It's not like you'd hear it, but admittedly it doesn't look too great and one might want to do some lowpass filtering.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
What makes an amplifier have a lower noise floor? pjpoes Solid State 27 2nd July 2007 12:20 AM
Noise floor rise on heathkit W4-AMs when power supply transformers were swapped terminatorx Tubes / Valves 4 8th October 2006 01:31 AM
noise floor w/ and w/o input signal gearheadgene Class D 18 6th September 2006 08:04 AM
noise floor problem johndiy Solid State 12 31st August 2006 01:32 AM
HOw close does driver need to be to floor to avoid floor bounce? Kanga Multi-Way 8 24th April 2003 06:09 AM


New To Site? Need Help?

All times are GMT. The time now is 04:58 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2