Regarding the transformer snubber values, these should be reasonably in the ballpark:
The snubbers are of course optional, but on some of my other DAC projects snubbing the isolated digital supply has made a noticeable difference to sound. Snubbing the analog supplies goes without saying
- For Block FL8/6 transformer: R1=100 Ohm
- For Triad FP12-475 transformer: R1=150 Ohm
The snubbers are of course optional, but on some of my other DAC projects snubbing the isolated digital supply has made a noticeable difference to sound. Snubbing the analog supplies goes without saying
Here is an updated power supply PCB design. It allows to use larger rectifiers.
The BOM is here: https://docs.google.com/spreadsheets/d/1JSQe4oLrP-48RUtvBtkkBYZrWAU63KZXvamnQo9BDqQ/edit?usp=sharing
I have also updated the input board documentation. It is linked from the first port of this thread.
The BOM is here: https://docs.google.com/spreadsheets/d/1JSQe4oLrP-48RUtvBtkkBYZrWAU63KZXvamnQo9BDqQ/edit?usp=sharing
I have also updated the input board documentation. It is linked from the first port of this thread.
Attachments
normundss,
I received and my integrated the input en switch boards to the DAM V2. Thanks again for arranging the group buy, very nice build and usefull!
Still a question: I want to add some GPIO and serial python2 code on my RPI2, I simply managed to read the DIYINHK status lines to drive and LCD. I could not get the serial connection working, I scoped the DAM TXD output, a 3.3V puls measured, but I can't read the same puls at pin 10 or 13 of the 40pin connector. What is the difference between RXD0 and RXD1? and it seems RN3 blocks the signal, what's RN3?, does it need control?
I received and my integrated the input en switch boards to the DAM V2. Thanks again for arranging the group buy, very nice build and usefull!
Still a question: I want to add some GPIO and serial python2 code on my RPI2, I simply managed to read the DIYINHK status lines to drive and LCD. I could not get the serial connection working, I scoped the DAM TXD output, a 3.3V puls measured, but I can't read the same puls at pin 10 or 13 of the 40pin connector. What is the difference between RXD0 and RXD1? and it seems RN3 blocks the signal, what's RN3?, does it need control?
For a single DAM build, the RXD0/TXD0 lines are used. RXD1/TXD1 are connected to the second DAM in balanced build, when serial port chaining is not used. It would require special configuration on RPi side to define a second serial port on these pins.
RN3 is a 1k resistor array that limits current to RPi GPIO pins to protect them in case of GPIO misconfiguration. If it blocks the signal, there is a chance it may not be soldered properly. Check it with a loupe to see if all pins are actually soldered. You can also check pcb continuity. Disconnect Raspberry and DAM, and measure resistance between pin8 of J19 connector and pin14 of the 26-pin connector (which is basically a breakout of DAM J2), and between pin 10 of J19 and pin 16 of 26-pin connector. Each should be 1 kOhm.
Also check the resistance between pin8 and pin10 of J19. It should be open circuit.
Has anybody a reference for a Raspberry Pi implementation in combination with the soekris dac ?
I try moode audio and have a lot of trouble.
I connect the Raspberry via normundss Input Board v2.
I don't find a solution to play music with different sample rates.
In case of direct I2S connection moode work well with setting upsampler to 192kHz/24 bit.
In case of connection to the Input Board via Raspberry adapter the soekris don't play the music. Playing music is possible after setting upsampler to only to 44.1kHz/24 bit and set the input switch to I2S. Set the switch to "Auto" it will not work.
I am confused and hope to get some hints.
Daniel
I try moode audio and have a lot of trouble.
I connect the Raspberry via normundss Input Board v2.
I don't find a solution to play music with different sample rates.
In case of direct I2S connection moode work well with setting upsampler to 192kHz/24 bit.
In case of connection to the Input Board via Raspberry adapter the soekris don't play the music. Playing music is possible after setting upsampler to only to 44.1kHz/24 bit and set the input switch to I2S. Set the switch to "Auto" it will not work.
I am confused and hope to get some hints.
Daniel
Auto selection will not work for I2S-2 (Raspberry) input. DAM1021 only has one I2S input that it can sense for auto selection, and it is configured on the input board to be I2S-1 (USB).
As for the sample rate problem, I don't know, have not used moode. The input board design was tested with up to 384 kHz sample rates from USB interface. I will try different sample rates on Raspberry, but from hardware perspective there should not be any difference between the two I2S inputs.
As for the sample rate problem, I don't know, have not used moode. The input board design was tested with up to 384 kHz sample rates from USB interface. I will try different sample rates on Raspberry, but from hardware perspective there should not be any difference between the two I2S inputs.
Thanks for Information!
What Raspberry Solution do you use with your Input Board?
Where is the difference between I2S-1/2? Where is I2S-2 connected to the dam ?
Is it possible to get the shematic from the Input Board?
Direct connection between the I2S and Raspberry works with upsampling set to 192kHz / 24 Bit.
But sorkris will not lock with same settings connected over the Input Board.
Daniel
What Raspberry Solution do you use with your Input Board?
Where is the difference between I2S-1/2? Where is I2S-2 connected to the dam ?
Is it possible to get the shematic from the Input Board?
Direct connection between the I2S and Raspberry works with upsampling set to 192kHz / 24 Bit.
But sorkris will not lock with same settings connected over the Input Board.
Daniel
I have tried plain Raspbian with mpd, and piCorePlayer. But I don't think I have specifically tried Raspberry with 192kHz output, only the USB input was tested with all sample rates.
I2S-1 and I2S-2 are both connected to the multiplexer chip on the input board. The output of that MUX goes to DAM. By default I2S-1 is selected, that is why DAM can use it for Auto input selection. There are no other differences between
I2S-1 and I2S-2. Do you have an Amanero or DIYINHK USB interface that you could try at higher sample rates?
I will try to test it with Raspberry at higher sample rates after the holidays.
I2S-1 and I2S-2 are both connected to the multiplexer chip on the input board. The output of that MUX goes to DAM. By default I2S-1 is selected, that is why DAM can use it for Auto input selection. There are no other differences between
I2S-1 and I2S-2. Do you have an Amanero or DIYINHK USB interface that you could try at higher sample rates?
I will try to test it with Raspberry at higher sample rates after the holidays.
No, I don't have an Amanero or DIYINHK USB interface.
Thanks for the explanation and shematic! Nosy about your raspberry test with higher sample rates.
When EXT PWR jumper is closed, 3.3V power is supplied from the onboard regulators.
When EXT PWR is open, 3.3V power is supplied externally. Typically this would be the case when using Amanero, which outputs 3.3V power derived from the USB bus.
Check the documentation for various other power options.
How are you powering the input board for your build?
When EXT PWR is open, 3.3V power is supplied externally. Typically this would be the case when using Amanero, which outputs 3.3V power derived from the USB bus.
Check the documentation for various other power options.
How are you powering the input board for your build?