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OPUS '41 does not work with 192 Khz sampling rate
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Hi,
Just replaced the old opus with the new opus. It works with 96 KHz, but if fed 192 KHz there is just static (using Metronome 1.0 which was set at 96, but also working at 192 with old opus). Any idea?
Thanks.
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glt wrote:Hi,
Just replaced the old opus with the new opus. It works with 96 KHz, but if fed 192 KHz there is just static (using Metronome 1.0 which was set at 96, but also working at 192 with old opus). Any idea?
Thanks. I am not able to replicate that. I am feeding my WM8741 192/24 music regularly both with the metronome and without. Perhaps another issue? Please give more details on how you have it setup. Source, wiring, etc. Cheers! Russ
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Rank: Member
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Hi Russ, thanks for the quick reply,
I put in the old 8740 OPUS and it works fine with 192K (thus the metro is fine).
My settings on the 8741 OPUS is as follows:
I2S +
DSD -
DEEMPH -
MODE -
IWO +
DIFFHW -
FSEL 0
MUTE 0
OSR 0
Thanks.
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I will also need to know how you have the metronome setup.
But FWIW there is no difference between the WM8741 and Wm8740 that would cause this.
My metronome is setup right now for 192/24 into the WM8741.
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Hi Russ, The metronome is set up just like this picture http://picasaweb.google....rU1Y#5150580913165881426(it is from your web site, but I can't find it now in your web site) Right now the 8740 is in the rig with the Metro in the above configuration. When I had it like this wiht the 8741 I was only getting loud static/hissing with and without music fed to the receiver thanks again for your help.
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Hi, all I really need is your actual jumper settings on the metronome.
Cheers!
Russ
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Hi Russ, here are the settings:
Metronome v1.0
MUTE open
RST open
IFMT2 -
IFMT1 -
IFMT0 +
BYPASS -
LGRP open
--- open
RDY open
OWL1 -
OWL2 -
OFMT1 -
OFMT0 +
MODE0 +
MODE1 - (works if +)
MODE2 -
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I did some more experiments:
The (-) pin for mode 1 has continuity to gnd
If I leave the mode 1 pin floating then it has the same static/hissing sound.
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Try setting the OSR pin high(+) on the Opus. You have it set low right now.
Cheers!
Russ
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Hi Russ,
That did it. Thank you so much!
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glt wrote:Hi Russ,
That did it. Thank you so much!
:) My pleasure. Cheers! Russ
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Hi,
On the Opus if i would put OSR to high, would lower sample rates still play.
My set up is Musiland 24/192 > Mux > Opus stereo
When i play 192Hz i only get hiss with OSR put at medium.
Gerard
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This one reason why people use our Metronome. :) Then you can setup the opus for one sample rate, say 192khz.
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So, I would need a metronome to play all sample rates without having to dip switch all the time ?? Nothing i can do with the mux clock frequenties to solve it? Edited by user Wednesday, March 9, 2011 9:15:33 AM(UTC)
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Thats the simplest way yes. You could also use some sort of firmware to detect the incoming sample rate and set OSR on the DAC, but that's not going to be nearly so easy. :)
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Thanks for quick reply, i will concider it, but i dont have much 192KHz material anyway and 96Khz is very satisfying.
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zonneveld wrote:Hi,
On the Opus if i would put OSR to high, would lower sample rates still play.
My set up is Musiland 24/192 > Mux > Opus stereo
When i play 192Hz i only get hiss with OSR put at medium.
Gerard That is the correct behavior. This is how it works: OSR-low tells the WM8741 to apply maximum oversampling, so only low sample rate content works. OSR-med tells the WM8741 to apply medium oversampling, so low sample rate and medium sample rate content works. OSR-high tells the WM8741 to NOT apply any oversampling, so any sample rate content works. Additional info here: http://hifiduino.blogspo...1/osr-bit-in-wm8741.htmlKeep in mind that the filters behave differently depending on the OSR as indicated in the data sheet and also explained here: http://hifiduino.blogspo...8741-filter-setting.htmlSo the only automatic solution is what Russ proposed: upsample everything before sending it to the OPUS
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Or as I said earlier to detect the sample rate and set the OSR via firmware (one could make good use of a counter on the word clock to do that). :) Either solution is viable, but up-sampling is by the easiest.
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Russ White wrote:Or as I said earlier to detect the sample rate and set the OSR via firmware (one could make good use of a counter on the word clock to do that). :) Either solution is viable, but up-sampling is by the easiest. I wonder why Wolfson did not implement a SR detector in the chip.
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Rank: Administration
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That would just make it way too easy ;)
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OPUS '41 does not work with 192 Khz sampling rate
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