A Zen I/V variant for the Saber DAC - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 16th October 2010, 05:06 PM   #11
jcx is offline jcx  United States
diyAudio Member
 
Join Date: Feb 2003
Location: ..
I am simulating a 2 tone balanced current input with dc bias from the PCM1794 data sheet

I like to look at IMD with 2 tone high frequency input as usually being most "stressful" distortion wise - the cs across the inputs is just a spice hack for balanced current excitation, the 2x 20KHz cs have opposite sign ac amplitudes

run the transient analysis and you should see 1:1 7KHz+20KHz output, I look at a 10mS long fft with Blackman window for good IMD product frequency resolution
Attached Images
File Type: png bal_zen_iv.png (73.5 KB, 530 views)

Last edited by jcx; 16th October 2010 at 05:27 PM.
  Reply With Quote
Old 16th October 2010, 05:38 PM   #12
diyAudio Member
 
Join Date: Feb 2010
Location: Dallas Fort Worth area, Texas
jcx,

Understood. Would this be simpler? It would also allow you to include the source imp from the DAC by adjusting the resistors. Those included here are for a 4x4 Sabre.

I will have to try this on the fully paralleled sim for the sabre.

Thanks,
Dave
Attached Images
File Type: jpg intermodsource.jpg (103.4 KB, 521 views)
  Reply With Quote
Old 16th October 2010, 06:28 PM   #13
jcx is offline jcx  United States
diyAudio Member
 
Join Date: Feb 2003
Location: ..
resistors would have to be in parallel with current sources, series with voltage sources

for the ESS9018 the Buffalo manual describes the analog out:

"Each analog output at 0DBFS is equivalent to a voltage of approximately 92.4% of AVCC in series with 195[Omhs]. So given 3.3VDC AVCC it will be about 3.05Vpp across 195[Omhs]. The output will be DC biased at AVCC/2. This works out to about 16ma peak to peak at each output. The amount of bias current will depend of the voltage of the virtual ground."
http://www.twistedpearaudio.com/docs...anual_v1.0.pdf
  Reply With Quote
Old 16th October 2010, 07:11 PM   #14
diyAudio Member
 
Join Date: Feb 2010
Location: Dallas Fort Worth area, Texas
jcx,

Yup, drew them incorrectly as current. I will use voltage sources with resistors to simulate the intermod sources. Thanks!

I use 15.612mA p-p for the simulations run to date (Sabre32 9018 in 4x4 stereo mode). This number is the typ number directly from the 9018 datasheet.

Dave
  Reply With Quote
Old 6th November 2010, 02:09 AM   #15
diyAudio Member
 
Join Date: Feb 2010
Location: Dallas Fort Worth area, Texas
Just an update on this project. I think I have a reasonable solution for Balanced to SE conversion on the Zen IV for balanced DACS like the Sabre. You can read about it here. Additional details about the circuit are here.

Enjoy!
Dave

To the moderator - I hope I am not breaking forum rules by pointing to other threads like this. It is an attempt to keep from polluting threads with off subject conversations while not repeating a bunch of information in multiple places... let me know if I am. Dave

Last edited by fitzfish; 6th November 2010 at 02:13 AM.
  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
hi cap or variant psu rocco gibralter Power Supplies 0 13th August 2009 10:55 PM
Tube output stage for Buffalo Saber 32-bit DAC? Curly Woods Tubes / Valves 0 23rd July 2009 02:18 PM
MP3 (Creative Zen) player to USB DAC? carleast Digital Source 2 7th January 2008 01:00 AM
is this an FE-103 variant? Scioneer Full Range 3 12th August 2007 04:11 AM
Zen DAC !?! Tyimo Pass Labs 14 24th October 2005 05:52 PM


New To Site? Need Help?

All times are GMT. The time now is 12:26 PM.


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