I removed the digital filter from my Philips based CD player in order to do the NOS mod. All is fine, but now there is no SPDIF output. So far it wasn't a problem, but now I want to try an external DAC. Any ideas?
Do you have schematic or a service manual for your player? If we can see how it worked originally, then it may be possible to figure out how to hook up an external dac. May also depend a lot on which external dac you might have in mind, or if you are thinking about building your own.
This is a Marantz CD-94. I have the SM for it. What I want to try is an external DIY DAC, the interface is not decided yet. I was thinking about I2S, perhaps it would be easier to install a Lemo connector and buffer the internal I2S signals (BCK, LRCK, DATA). The new external DAC has I2S input anyway. By adding MCK even reclocking will be possible. 5-pole connector, hm...
LVCMOS I2S signals should't be very long. Maybe a few CM at most, although I have used 50-ohm coax with u.fl connectors to go a longer distance. Also used galvanic isolation at the receiving end along with reclocking using using MCLK. Even for short distances, each I2S signal wire should have its own dedicated ground wire. Loosely twisting each signal wire with its dedicated ground wire can help maintain signal integrity over short distances.
OTOH, dacs that have I2S inputs use LVDS signals (there is a standard defined by PS Audio, but not everyone follows it exactly). Since LVDS signals are balanced low voltage they can run much longer distances, while having better noise immunity. There are ICs available for converting between LVCMOS and LVDS signal types.
Database with multiple sheets at: https://docs.google.com/spreadsheets/d/1h5PMUBkldkpt1rCnAR4ZHYGZNeCe-vwIFyKWYMZWsX0/edit?pli=1#gid=0
Some other info: https://www.ricable.com/en/il-protocollo-i2s-e-il-cavo-supreme-hdmi/
OTOH, dacs that have I2S inputs use LVDS signals (there is a standard defined by PS Audio, but not everyone follows it exactly). Since LVDS signals are balanced low voltage they can run much longer distances, while having better noise immunity. There are ICs available for converting between LVCMOS and LVDS signal types.
Database with multiple sheets at: https://docs.google.com/spreadsheets/d/1h5PMUBkldkpt1rCnAR4ZHYGZNeCe-vwIFyKWYMZWsX0/edit?pli=1#gid=0
Some other info: https://www.ricable.com/en/il-protocollo-i2s-e-il-cavo-supreme-hdmi/
Hi, I need to get a better performing spdif output from my Philips CD 960 than the one generated by the SAA7220 filter.
The idea would be to split I2S coming from SAA7210 and send it to the input of WM8804. I would need to confirm that the WM8804 setting is correct especially regarding PIN1 SCLK AIF/MS .
Please see settings below;
The idea would be to split I2S coming from SAA7210 and send it to the input of WM8804. I would need to confirm that the WM8804 setting is correct especially regarding PIN1 SCLK AIF/MS .
Please see settings below;
Recommended I2S IN/SPDIF OUT Configuration:
| PIN1 | SCLK | AIF/MS | 0 NOTE:SLAVE MODE MCLK IS INPUT |
| PIN2 | IGPO0 | *AIFCONF1 | 0 NOTE:I2S@16BIT |
| PIN3 | SDIN | HWMODE/SOFTMODE | 0 NOTE:HW MODE |
| PIN4 | SDOUT | *AIFCONF0 | 0 NOTE:I2S@16BIT |
| PIN5 | CSB | TXSRC | 1 NOTE:TRANSMIT FROM DATA IN |
Audio Interface Format Table
AIF Configuration Format | ||
| IGPO0/AIFCONF1 | SDOUT/AIFCONF0 | |
| 0 | 0 | 16 bit I2S |
| 0 | 1 | 24 bit I2S |
| 1 | 0 | 24 bit right justified with flags |
| 1 | 1 | 16 bit left justified |
I2S PIN INPUT
| PIN13 | DIN | DATA IN |
| PIN14 | BCLK | BIT CLOCK IN |
| PIN15 | LRCK | LEFT/RIGHT WORD CLOCK IN |
| PIN16 | MCLK | MASTER CLOCK IN |