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Mr White's "Opus", designing a simple balanced DAC

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Decided to buy an Opus...
After thad decided to not buy an Opus...
Three weeks ago I suddenly changed my mind and
decided to Buy an Opus.
Then lightning struck and I needed new glasses so I decided
again to not buy an Opus.
But since I'm only human I decided to buy an Opus after all...
And now it is out of stock. Just my bad luck...

Any idea when it wil be back in stock again? Before I change my mind again?
:p
 
Last edited:
Decided to buy an Opus...
After thad decided to not buy an Opus...
Three weeks ago I suddenly changed my mind and
decided to Buy an Opus.
Then lightning struck and I needed new glasses so I decided
again to not buy an Opus.
But since I'm only human I decided to buy an Opus after all...
And now it is out of stock. Just my bad luck...

Any idea when it wil be back in stock again? Before I change my mind again?
:p

I think they are to busy with their families .;)
 
Decided to buy an Opus...
After thad decided to not buy an Opus...
Three weeks ago I suddenly changed my mind and
decided to Buy an Opus.
Then lightning struck and I needed new glasses so I decided
again to not buy an Opus.
But since I'm only human I decided to buy an Opus after all...
And now it is out of stock. Just my bad luck...

Any idea when it wil be back in stock again? Before I change my mind again?
:p

Hesitated some more and finally jumped. My Opus is waiting for a plane in New York at the moment!
:D
 
Member
Joined 2008
Paid Member
Hey all,

Managed to hook up my LCDPS + OPUS DAC 2.1 board to a jkeny hiface USB I2S module last night. Sounding great from 44khz to 96khz files. Doesn't seem to work with 174khz or 192khz files. Just get a constant 'FM radio static' like noise. I noticed this when I try the Test bell playback sound under windows 7 -> control panel -> sounds -> playback devices -> supported formats. 44/48/88/96 would play perfectly, but 174/192 would just give off that static noise and stay like that until I play something between 44-96khz. Have asked jkeny for any advice and his reply:

- the Hiface uses MCLK of
- 128*fs for 176.4 & 192KHz;
- 256*fs for 88.2 & 96KHz;
- 512*fs for 48 & 44.1KHz.

You might check that this is the MCLK speeds that the WM8741 expects?


I'm not technical enough to understand if there is a compatibility issue or I have not configured the settings of the dac properly? I did show jkeny the photos below and he did say they seem to be wired up correctly.

Is anyone able to shed any light as to why or what may be causing me not to be able to playback the 174/192 signals? As far as I know, the WM8741 chip supports 24/192 and the jkeny hiface usb i2s (based on hiface evo) supports 24/192 output too..

thanks in advance :)
Tuyen

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.
 
Member
Joined 2008
Paid Member
Hi HAL2010,

I just did some intense googling and found what each dip switch does and I did notice that OSR one you mention.

As my DAC was on default recommended settings as in OPUS manual, it was set on the middle point (88/96). If I switch it to 1 (176/192) will it affect the quality of playback (in theory) of 44 and 88/96 files ?

Thanks for your prompt reply.

Muchly appreciated. :)
Tuyen
 
Hi HAL2010,

I just did some intense googling and found what each dip switch does and I did notice that OSR one you mention.

As my DAC was on default recommended settings as in OPUS manual, it was set on the middle point (88/96). If I switch it to 1 (176/192) will it affect the quality of playback (in theory) of 44 and 88/96 files ?

Thanks for your prompt reply.

Muchly appreciated. :)
Tuyen

I use the switch to select the native sample rate of the file played.

You will have to decide if the difference in sound quality is audible in your setup.
 
Hi HAL2010,

I just did some intense googling and found what each dip switch does and I did notice that OSR one you mention.

As my DAC was on default recommended settings as in OPUS manual, it was set on the middle point (88/96). If I switch it to 1 (176/192) will it affect the quality of playback (in theory) of 44 and 88/96 files ?

Thanks for your prompt reply.

Muchly appreciated. :)
Tuyen

What is happening is that you turn off the internal oversampling when setting the switch to high sample rate, use 2x oversampling with the middle setting and 4x oversampling with the lowest setting.

H I F I D U I N O: OSR bits in WM8741
 
Member
Joined 2007
Paid Member
What is happening is that you turn off the internal oversampling when setting the switch to high sample rate, use 2x oversampling with the middle setting and 4x oversampling with the lowest setting.

H I F I D U I N O: OSR bits in WM8741

In addition you influence the internal filter performance. In my experience it is definitely best to match the OSR setting to the source frequency. To simplify this, I usually up/down sample everything to 96kHz in the player OS, which is clearly less destructive than playing with OSR set wrong on the 8741.

YMMV, of course...

Frank
 
Member
Joined 2007
Paid Member
I use a modified version of glt's HiFiDuino code on an Freeduino uC to control the Opus via the I2C bus for both the OSR and FSEL settings for each file I play back. It is easy with an IR remote control to do this for every song if needed.

Elegant implementation! I have front panel switches for OSR and FSEL, but run a blend of Opus and Buffalo DACs.
 
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