WM8804 Software Control

[fmak]

To my annoyance. the WM8804/5 does not work at 176.4 kHz in hardware mode, even though it seems to provide good results at other frequencies. It also has a problem of always locking on when fs is changed, requiring a reset.

Has anyone implememented software control as a diy project? I would like to use the chip as a dejitterer outputting both I2S and spdif.

[Jambo]

Yea, I have successfully done it on a WM8805, see my thread here:

http://www.head-fi.org/forums/f6/jambo-dac-288159/

[rossl]

I made a comment in the following thread about the 176K problem with the Wolfson.

Digital Audio Receiver / SRC Chips

Even in software control, it is going to be hard to fix. I suppose a micro can watch the LOCK and TRANS_ERR outputs and make it switch.

Even so, that would add more time to lock, and that may be undesirable.

I gave up on using the Wolfson part in the DAC that I am working on... just because of this problem. I may look at it later.

[fmak]

Originally posted by Jambo
Yea, I have successfully done it on a WM8805, see my thread here:

http://www.head-fi.org/forums/f6/jambo-dac-288159/

Jambo

I am interested in your board with AD797. Do you still have one with parts?

You can email me.

Fred

[kevinkr]

Originally posted by fmak
To my annoyance. the WM8804/5 does not work at 176.4 kHz in hardware mode, even though it seems to provide good results at other frequencies. It also has a problem of always locking on when fs is changed, requiring a reset.

Has anyone implememented software control as a diy project? I would like to use the chip as a dejitterer outputting both I2S and spdif.

I use mine only over the range of 32K to 96K and over this range the TPA receiver module locks just fine in hardware mode. I'm not aware of any untoward behavior as long as the data rate is in this range. Below this range results in interesting noises being generated, I have deliberately set my media server default sample rate to 44.1kHz so that the dac almost always has a valid spdif signal to lock on when idle. The sample rate is not locked so it can change dynamically as required by whatever player mode I am using. (M-Audio 2496 Audiophile PCI sound card)

Otherwise I am completely happy with the performance of my new dac.

I would be interested in the software control project as well, specifically because I am interested in getting at the de-emphasis flag for automatically controlling de-emphasis when required on the few disks that do use it.

[rossl]

Originally posted by kevinkr


I use mine only over the range of 32K to 96K and over this range the TPA receiver module locks just fine in hardware mode. I'm not aware of any untoward behavior as long as the data rate is in this range.

Yes, I concur with that. My test of the WM8804 in hardware mode shows that it works wonderfully in that range of sample rates and also at 192K.

It will not work at all at 176.4K in hardware mode.

bummer!

[kevinkr]

Anyone working on a pic uP or similar for software mode control of the WM8804.. I'm still interested..

[powerpan]

I use AVR software control 8805.
not know if it could work under 176K

[Telstar]

Originally posted by fmak
To my annoyance. the WM8804/5 does not work at 176.4 kHz in hardware mode, even though it seems to provide good results at other frequencies. It also has a problem of always locking on when fs is changed, requiring a reset.

Has anyone implememented software control as a diy project? I would like to use the chip as a dejitterer outputting both I2S and spdif.

Bumping this because I plan to use this receiver.

[kevinkr]

I'm also interested in this. I haven't had any issues with synchronizing to different sample rates, (without a reset) but none of my sources go above 96K.