Go Back   Home > Forums > >

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

WM8805 problem
WM8805 problem
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
Old 23rd May 2017, 10:29 AM   #1
kropka235 is offline kropka235
diyAudio Member
 
Join Date: Sep 2011
Default WM8805 problem

Hi.
I've been playing with wm8805 chip lately and i really love the sound of that chip but i cant get it to lock on anything higher than 16/44.
If i play higher res.like 24/96 Files the sound gets hiccups and if i play 24/192 than i get no sound and lots of crackles.
Im using spdif input with cap in series and 75ohm to ground. ...the chip is connected to wm8741 dac (i2s).
The chip is setup in hardware mode and it suppose to support all data up to 192.
...i cant figure out what im doing wrong.
But it sound amazing with 16/44 files.
Has anyone experience similar problem with wm8805?, if you have any suggestions please let me know.
K.
  Reply With Quote
Old 23rd May 2017, 05:40 PM   #2
percival007 is offline percival007  England
diyAudio Member
 
Join Date: Sep 2007
I've never managed to get a WM8805 to accept anything above 96kHz in Hardware Mode.
If it is possible I'd be interested to know how to do this. I have a vague feeling there is something in the Datasheet that says it isn't capable in H/D Mode but having just trawled through it I can't find it !!

I have though no trouble in getting it to work with 96kHz material.
What is your SPDIF source? Optical or Coaxial?
I had trouble with one particular Optical Receiver and ended up doing away with the 75 OHM Resistor across the 8805's Digi I/P.

P.
  Reply With Quote
Old 23rd May 2017, 10:34 PM   #3
kropka235 is offline kropka235
diyAudio Member
 
Join Date: Sep 2011
Hi
Percival007 ...and many thanx for your reply.
...my spdif source is coaxial and i do everything as described in data sheet and still cant get it locked on 96 properly.,...the sound is there but it crackles.
...i use 12mhz oscillator with dedicated 5v psu.
Pins that i keep high are: 4,8,10,11
Pins kept low : 5,7
Spdif input pin 3
....any suggestions?
Best and many thanx.
  Reply With Quote
Old 24th May 2017, 07:07 AM   #4
percival007 is offline percival007  England
diyAudio Member
 
Join Date: Sep 2007
Quote:
Originally Posted by kropka235 View Post
...i use 12mhz oscillator with dedicated 5v psu.....
Do you mean that the Oscillator has it's own dedicated 5V Supply? If you mean you are supplying the 8805 with 5V this may be a problem. It may be better run from a 3.3V Supply. +5 is an absolute Max according to the datasheet.
Quote:
Originally Posted by kropka235 View Post
.....Pins that i keep high are: 4,8,10,11
Pins kept low : 5,7
What are you doing with Pin 9?
Pin 10 is a Reset and needs a Cap to Ground too.

What DAC are you feeding from the 8805?

I feed a TDA1541A and I configure it like so.......
Pins 5,8 and 9 = Low
Pin 4 = High

Cheers,

P.

Last edited by percival007; 24th May 2017 at 07:09 AM.
  Reply With Quote
Old 24th May 2017, 09:20 AM   #5
kropka235 is offline kropka235
diyAudio Member
 
Join Date: Sep 2011
Thats right, i use 3.3v to power dvdd and pvdd and 5v is just to power 4 pin crystal
Thats the power that crystal needs to work.
Perhaps you are using 12mhz 2 pin crystal connected between pins14/15.
...i keep pin 4 high obviously, ...pin 5 kept low,...pin 9 i didn't even connect so im assuming that is low and as far as i understand pin 9 is just Unlock flag in HW mode.
Pin 8 i keep high opposed to you.
Keeping pin 8 high means i2s 24bit....and that's what i want.
...you keep that pin low and that means you selectedi2s 16bit or 24bit left justified with flags.
...im not using any flags.
...i will try to change to your settings but i dont think that will change anything.
...im using my wm8805 with wm8741 dac chip.
I2s connection with 33ohm resistors.
..and pin 10 reset has 10uf to ground.
  Reply With Quote
Old 24th May 2017, 06:07 PM   #6
percival007 is offline percival007  England
diyAudio Member
 
Join Date: Sep 2007
Pin 9 (CSB/GP02) is a Flag once the IC is up and running, before this, in H/W Mode the pins 4,5,8 & 9 set up the chip.
Pin 9 tells the IC how to route the SPDIF.

I have found these pins aren't good if left 'floating'. It's best to tie them to Supply or 0V.

Cheers, P.
  Reply With Quote
Old 24th May 2017, 07:40 PM   #7
kropka235 is offline kropka235
diyAudio Member
 
Join Date: Sep 2011
...that makes sens and i will give it a go and let you know my findings.
...thanx!
  Reply With Quote
Old 25th May 2017, 08:41 AM   #8
kropka235 is offline kropka235
diyAudio Member
 
Join Date: Sep 2011
Pin 9 made no difference. I did have it low/high...and back to floating.
Changing oscillator from 4 pin to 2 pin and placing it between pins 14/15 with two 15pf caps to ground ....finally made 24/96 possible! .
So partially problem solved! .
But 16/44 and 24/96 are the only formats the chip locks on at the moment. ..other formats still crackling
Any idea?.
many thanks for your valuable suggestions
K.
  Reply With Quote
Old 25th May 2017, 05:57 PM   #9
percival007 is offline percival007  England
diyAudio Member
 
Join Date: Sep 2007
That's great news.

Can you get 48kHz or 88.2kHz to work?

Anything higher than 96 kHz I really don't think is possible. I'm not 100% certain I really understand it but on Page 28 of the Datasheet it says.........

''.............The PLL register settings are configured by default to allow 32/44.1/48/88.2/96kHz (modes 2/3/4) sample rate S/PDIF receiver operation using a 12MHz crystal clock. The PLL register settings must be updated if:
• Any crystal clock frequency other than 12MHz is used.
OR
• A S/PDIF stream with 192kHz sample rate (mode 1) is detected................''

I don't think you can change those 'Modes' other than in Software Mode. If you find out how, I'd like to know also.

Cheers,

P.
  Reply With Quote
Old 25th May 2017, 10:13 PM   #10
nattawa is offline nattawa  Canada
diyAudio Member
 
Join Date: Apr 2010
Location: Mississauga, Ontario
WM8805 needs a bit of "help" if wished to receive streams of sample rate higher than 96K, namely 176.4K and 192K.

This is because in order to lock onto a 192K sample rate stream, WM8805's internal PLL must start to operate at a different set of division parameters (PLL_K and PLL_N) than a common set of parameters that's good for all other sample rates, yet ironically, WM8805 is unable to tell a 192K incoming stream from a 176.4K one, and therefore, unable to decide by itself when to switch to the correct set of PLL parameters.

The data sheet has no info about how the PLL parameter switching are handled in hardware mode. I would then hazard a guess that it is not handled at all, hence the chip would stick with one set of parameters, which is good for up to 176.4K, and ditch the support to 192K.

In my Whazon Spdif switch project (software mode operation), an Arduino Nano micro-controller helps by clocking the recovered LRCK cycle period and then accordingly, loading the control registers with proper set of PLL parameters. This seems to be the only way of getting WM8805 to reliably operate on 192K and all other supported sample rates.
  Reply With Quote

Reply


WM8805 problemHide this!Advertise here!
Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
WM8805 as MCLK source? elektryk Digital Line Level 0 17th May 2015 10:38 AM
Help Using WM8805 in HW Mode bimbla Digital Line Level 21 2nd March 2015 01:47 PM
WM8805 - AD1865 mkanna Digital Source 1 23rd November 2014 03:58 PM
Wanted: 1 piece WM8805 Groundloops Swap Meet 2 8th May 2013 08:44 AM
WTB wm8805 Kovax Swap Meet 0 22nd May 2010 06:12 PM


New To Site? Need Help?

All times are GMT. The time now is 10:28 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki