I have asked similar questions in the Class D forum but it seems here they are more home.
I have completed a digital xover on PC. Filtered signal for individual speaker drivers (4 channels needed, i.e. two stereo) is output by M-Audio Delta 410 soundcard. It works without problems with Delta SPDIF. Now I am trying to connect i2s from the soundcard’s audio controller directly to the Panasonic SA-XR55 Equibit receiver main board. I would not like to use SPDIF for two good reasons – better quality and even more since Panasonic has only one SPDIF while I need two stereo signals (fed directly digitally).
I want to connect the Delta i2s lines to a Panasonic 26-pin connector between a DSP PCB (with an SPDIF transceiver, A/D and Yamaha YSS944 DSP) and the main board with two TAS5076 PWM processors.
I checked that:
- both (Envy and TAS5076) operate at 3,3 V,
- the master clock is 256fs for both,
- Panny is 64-bit per frame, so can be configured Envy,
Envy outputs signal in the proper i2s, Panny can accept them as well as many others.
Yamaha DSP that feeds 5076 in the standard Panny also can output different formats including the proper i2s. Do you think there is a good chance of format match or it is likely that I will have to set some 5076 control registers ?
I have worked out more less the internals of the Panny and would like to begin experimenting but as I am not experienced with low-level digital chip mods I would like to confirm with you that I am doing the right things:
1. From the Envy24 soundcard controller (ICE 1712) I will tap into the following lines (basically off the input pins of the mujltichannel codec AK4529VQ):
- SDT0-3 for I2S data (standard i2S),
- BICK – bit clock,
- LRCK – wordclock
- MLCK – master clock
And here the first question: on the soundcard PCB it seems there is a very small resistor in the MLCK signal path –shall I tap into the signal before or after it ?
Another is can I safely connect to the current circuit or do I have to cut the paths on the PCB and put some buffers or whatever needed ?
2. Do you think it is safe to disconnect completely 26-pin connector between a DSP PCB (with an SPDIF transceiver, A/D and Yamaha YSS944 DSP) and the main board with two TAS-es 5076 and provide only the i2s signals ? Is it risky experimenting with that or the typical thing that can happen is that it will not play ?
I have completed a digital xover on PC. Filtered signal for individual speaker drivers (4 channels needed, i.e. two stereo) is output by M-Audio Delta 410 soundcard. It works without problems with Delta SPDIF. Now I am trying to connect i2s from the soundcard’s audio controller directly to the Panasonic SA-XR55 Equibit receiver main board. I would not like to use SPDIF for two good reasons – better quality and even more since Panasonic has only one SPDIF while I need two stereo signals (fed directly digitally).
I want to connect the Delta i2s lines to a Panasonic 26-pin connector between a DSP PCB (with an SPDIF transceiver, A/D and Yamaha YSS944 DSP) and the main board with two TAS5076 PWM processors.
I checked that:
- both (Envy and TAS5076) operate at 3,3 V,
- the master clock is 256fs for both,
- Panny is 64-bit per frame, so can be configured Envy,
Envy outputs signal in the proper i2s, Panny can accept them as well as many others.
Yamaha DSP that feeds 5076 in the standard Panny also can output different formats including the proper i2s. Do you think there is a good chance of format match or it is likely that I will have to set some 5076 control registers ?
I have worked out more less the internals of the Panny and would like to begin experimenting but as I am not experienced with low-level digital chip mods I would like to confirm with you that I am doing the right things:
1. From the Envy24 soundcard controller (ICE 1712) I will tap into the following lines (basically off the input pins of the mujltichannel codec AK4529VQ):
- SDT0-3 for I2S data (standard i2S),
- BICK – bit clock,
- LRCK – wordclock
- MLCK – master clock
And here the first question: on the soundcard PCB it seems there is a very small resistor in the MLCK signal path –shall I tap into the signal before or after it ?
Another is can I safely connect to the current circuit or do I have to cut the paths on the PCB and put some buffers or whatever needed ?
2. Do you think it is safe to disconnect completely 26-pin connector between a DSP PCB (with an SPDIF transceiver, A/D and Yamaha YSS944 DSP) and the main board with two TAS-es 5076 and provide only the i2s signals ? Is it risky experimenting with that or the typical thing that can happen is that it will not play ?
Regarding question 1), it does not really matter, the resistor is there to provide a little bit of extra insulation. What I would do, I would use a line driver / buffer chip for each of these signals. For standard TTL, ALS would do nicely, i.e. something like 74ALS244. If you have to bridge more than say 1 m, try differential transmitters and receivers.
Are you positive that Envy and AKM have been set up to use I2S data? The AKM data sheet is back online (it wasn't available last time I looked over a year ago), and the chip acutally has left and right justified modes in addition to I2S. Also, the digital audio interface can be reconfigured to TDM mode, which would further complicate interfacing.
As far as I can see, all these modes are controlled by pins rather than software, so measuring the voltage at these pins should be sufficient.
Are you positive that Envy and AKM have been set up to use I2S data? The AKM data sheet is back online (it wasn't available last time I looked over a year ago), and the chip acutally has left and right justified modes in addition to I2S. Also, the digital audio interface can be reconfigured to TDM mode, which would further complicate interfacing.
As far as I can see, all these modes are controlled by pins rather than software, so measuring the voltage at these pins should be sufficient.
Resurrecting this thread as I wish to do the same thing. Has anybody else achieved this?
Could you connect to the input pins marked on the schematic attached & retain volume control?
I would hope to provide a cleaner PS supply to the output stage probably using batteries & I don't know how these vol issues would work out!
Could you connect to the input pins marked on the schematic attached & retain volume control?
I would hope to provide a cleaner PS supply to the output stage probably using batteries & I don't know how these vol issues would work out!
Any answers yet guys? Did anybody achieve this?
I'm looking at the same issue with XR57 but wondered how you did it - I don't think the amp will work without the 26 pin connector between DSP board & main board.
Did you consider the splicing into the pins going into the YSS944 IC from IC1004, a logic IC?
I'm looking at the same issue with XR57 but wondered how you did it - I don't think the amp will work without the 26 pin connector between DSP board & main board.
Did you consider the splicing into the pins going into the YSS944 IC from IC1004, a logic IC?
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