Søren, I see from the 1941 thread that you’re in a firmware kind of mood 
As it’s still winter and the weather isn’t quite summer-like can you move the 1121 firmware with the 4K filters up the priority list before those summers get in the way again?
Once done, you could reward yourself for all that hard work and come and relax in my part of the world - rum, beaches, sun.... you know, where it’s always summer!!
Signed
Your (2nd) Favourite Nag
As it’s still winter and the weather isn’t quite summer-like can you move the 1121 firmware with the 4K filters up the priority list before those summers get in the way again?
Once done, you could reward yourself for all that hard work and come and relax in my part of the world - rum, beaches, sun.... you know, where it’s always summer!!
Signed
Your (2nd) Favourite Nag
Søren, I see from the 1941 thread that you’re in a firmware kind of mood
As it’s still winter and the weather isn’t quite summer-like can you move the 1121 firmware with the 4K filters up the priority list before those summers get in the way again?
Once done, you could reward yourself for all that hard work and come and relax in my part of the world - rum, beaches, sun.... you know, where it’s always summer!!
Signed
Your (2nd) Favourite Nag
I'm actaully thinking about that, I'm working to change the whole clocking scheme to fix the clicks on the dam1021 and recently also reported on the dam1941, which by coincidence will make the dam1121 easier to update to 4K taps....
Last edited:
Just a note there, Since doing the original dam1121 manual I discovered that the max3280 is not really that good chip for the job, it have a failsave mode which reduce it's sensitivety. I recommend using an old RS422 receiver chip instead, like a 26LV32.
Great! May summer be late this year...at least in Denmark. I shall save that bottle of 23-year old rum I just managed to get hold of for when I upload those taps. Don’t make me wait too long, please....the rum needs opening.
I have a dam1121 on route coming from Denmark
I guess it will certainly improve my e-bay ES9023 board
Preparing on the build I have some questions:
I will use a single board with single-ended outputs, playing only PCM (most 16/44.1)
I have already read the note about changing the max3280 for 26LV32 in the SPDIF circuit.
As I also want to use a switch (between Coax and Toslink), which 2-ch switcher would be best ?
How critical is the analog power supply - we can of course go ballistic but how sensitive is the dam1121 in this regard ?
What other design considerations are worth the extra costs / components ?
Does an external clock make a noticable difference ?
I plan to isolate the I2S signal coming from a BeagleBone Black (botic version) with an IL715 digital isolator. Any potential issues here ?
Thank you in advance
I guess it will certainly improve my e-bay ES9023 board
Preparing on the build I have some questions:
I will use a single board with single-ended outputs, playing only PCM (most 16/44.1)
I have already read the note about changing the max3280 for 26LV32 in the SPDIF circuit.
As I also want to use a switch (between Coax and Toslink), which 2-ch switcher would be best ?
How critical is the analog power supply - we can of course go ballistic but how sensitive is the dam1121 in this regard ?
What other design considerations are worth the extra costs / components ?
Does an external clock make a noticable difference ?
I plan to isolate the I2S signal coming from a BeagleBone Black (botic version) with an IL715 digital isolator. Any potential issues here ?
Thank you in advance
Last edited:
Has anyone encountered the DAM 1121 suddenly unable to lock to the music via I2S?
My unit exhibits this randomly and usually happens between the 2nd or 3rd song. It was working okay until recently. :-(
When this happens, I have to let the unit rest for up to 10 minutes in order to restart it and the problem will occur again.
My unit exhibits this randomly and usually happens between the 2nd or 3rd song. It was working okay until recently. :-(
When this happens, I have to let the unit rest for up to 10 minutes in order to restart it and the problem will occur again.
I used an infrared thermometer to check the boards and there are no signs of hot spots. Also tested all the voltages and they measure correctly.
Currently using 3 Salas UBiB shunt regulators for the digital 5V and analog +/-5V rails.
Will attempt to use an alternative source this weekend to see if the problem persists.
I only swapped a different software which I confirmed working on the TDA1541A which is also via I2S.
If I ever decide to upgrade my dam1121-02 with an external Si570 I guess the termination resistor at the Si570 end must also be 100 ohms ?
The manual describes that there is already a 100 ohm resistor at the receiver end.
From the manual:
The LVDS clock signal must be connected, terminated and routed carefully. It is point to point and must be terminated correctly at the far end only, the dam1121 internal LVDS receiver have a 100 ohm termination.
Is "the far end" the Si570 or the receiver chip ??
Looking at the schematic where 2 boards are linked for balanced operation I see no termination resistors near the Si570.
Can somebody explain how to connect it correctly ?
FYI:
I am planning a PCB with female sockets to mount directly on the dam1121.
On this additional board I can mount the Si570 only mm's away from the J3 pins
This board will also be used for multiple LDO's, SPDIF receiver and Toslink switcher and have a digital isolator for incoming I2S from the BeagleBone Black.
So it is like a Cape known from BBB or RPi with all the needed additional circuitry.
The manual describes that there is already a 100 ohm resistor at the receiver end.
From the manual:
The LVDS clock signal must be connected, terminated and routed carefully. It is point to point and must be terminated correctly at the far end only, the dam1121 internal LVDS receiver have a 100 ohm termination.
Is "the far end" the Si570 or the receiver chip ??
Looking at the schematic where 2 boards are linked for balanced operation I see no termination resistors near the Si570.
Can somebody explain how to connect it correctly ?
FYI:
I am planning a PCB with female sockets to mount directly on the dam1121.
On this additional board I can mount the Si570 only mm's away from the J3 pins
This board will also be used for multiple LDO's, SPDIF receiver and Toslink switcher and have a digital isolator for incoming I2S from the BeagleBone Black.
So it is like a Cape known from BBB or RPi with all the needed additional circuitry.
Oystein - back in this thread is a post confirming that the -01 version of the 1121 uses an Si570. If you’re only using a single 1121 it might be easier to simply upgrade your -02 to an -01 as I suspect that any advantage the external Si570 provides will be lost in all the PCB traces, their implementation etc.