Hello,
I am building a digital crossover for my active loudspeakers based od Audiophonics XMOS USB-I2S - miniSharc - and 3x Audiophonics PCM5102 DAC. The crossover is ready and it works fine however I have a problem with startup. If all the boards are connected the XMOS is not recognized by the PC. A can start-up the crossover only if I disconnect minisharc from the XMOS board, connecting the PC to XMOS and then connecting the minisharc to XMOS board. In that case everithing works. whre can be the problem and how can I solve it?
Thank you in advance!
Frank
I am building a digital crossover for my active loudspeakers based od Audiophonics XMOS USB-I2S - miniSharc - and 3x Audiophonics PCM5102 DAC. The crossover is ready and it works fine however I have a problem with startup. If all the boards are connected the XMOS is not recognized by the PC. A can start-up the crossover only if I disconnect minisharc from the XMOS board, connecting the PC to XMOS and then connecting the minisharc to XMOS board. In that case everithing works. whre can be the problem and how can I solve it?
Thank you in advance!
Frank
Does it behave the same when you connect the USB-I2S directly to one of the PCM5102 (thus without the MinSharc in the chain)?
I have not tried, I can try to recable it. Do you think the I2S isolator could help to solve the problem?
Frank
Frank
I2S isolator: don't know. Which one?
If the XMOS USB-I2S behave's the same (not being recognized by your PC) when directly connected to a DAC as when connected to the MiniSharc you'll have to get support from audiophonics.
With PC you mean a PC with Windows operating system? Do you have the possibility to test with Apple or linux? Maybe it's not a hardware but ome software conflict.
Do you have the USB connection to the MiniSharc also in use when you power on your cross-over?
If the XMOS USB-I2S behave's the same (not being recognized by your PC) when directly connected to a DAC as when connected to the MiniSharc you'll have to get support from audiophonics.
With PC you mean a PC with Windows operating system? Do you have the possibility to test with Apple or linux? Maybe it's not a hardware but ome software conflict.
Do you have the USB connection to the MiniSharc also in use when you power on your cross-over?
I have no USB connected to the minisharc. If I have everithing conncted (also minisharc to USB) and minisharc is not connected to the XMOS it starts up. If I have everithing disconnected, also the dac, etc and the minisharc is connected to XMOS it does not start up. I have win7. After starting up I can connect everithing (all the 3 DAC boards, minisharc, USB to minisharc) and disconnect..... it works.
Does it make a difference when you power up your cross-over with or without the XMOS connected to your PC (and everything else inside the x-over connected)? Maybe it is recognized after power up but only when not initially connected to the PC.
No difference. I can switch it on with or without the USB connection. If the minisharc is connected it is not recognized, when the minisharc is disconnected it works.
I have started to study the minisharc manual if there is any difference if the minisharc is powered via main mower connector or via J2 however there is no any information which pins have to be connected to the source. There are 7 GND pins and 2 3,3V pins. No any information whether they are an input power or output power pins to the DAC. No information which GND pins have to be connected or it is enough if I connect the GND via main power (DC Input).
I have started to study the minisharc manual if there is any difference if the minisharc is powered via main mower connector or via J2 however there is no any information which pins have to be connected to the source. There are 7 GND pins and 2 3,3V pins. No any information whether they are an input power or output power pins to the DAC. No information which GND pins have to be connected or it is enough if I connect the GND via main power (DC Input).
The 2 pin connector is there to power the MiniSharc. The 3.3V on the extension header is only output.
The strange thing is that when you connect the XMOS to the Minisharc after it is powered up your PC recognizes the XMOS USB.
I strongly suggest to run a few wires directly to one of the DAC's and see if it behaves the same.
The strange thing is that when you connect the XMOS to the Minisharc after it is powered up your PC recognizes the XMOS USB.
I strongly suggest to run a few wires directly to one of the DAC's and see if it behaves the same.
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Some random thought: what happens if you do not disconnect the I2S wires but leave the MiniSharc un-powered and power it up after the XMOS has powered up.
Nothing happens. The XMOS starts op only in case that the 3 wires are disconnected from minisharc(data, bck lrck). I have tried lot of combinations. It always starts up if this 3 wires are disconnected and never if they are connected before the xmos is recognized by PC.
I find it difficult to understand why the USB to I2S interface malfunctions when the output is connected to the MiniSharc during power-up. Scratching my head.....
Aside the 2 clock and 1 data line, did you also wire a GND return between the USB and the Minisharc board?
Can you post one or more pictures?
Are you running the MiniSharc in Master or Slave mode? Do you use the ASRC on the I2S input?
Aside the 2 clock and 1 data line, did you also wire a GND return between the USB and the Minisharc board?
Can you post one or more pictures?
Are you running the MiniSharc in Master or Slave mode? Do you use the ASRC on the I2S input?
Do you use this USB to I2S board?
It looks like this board outputs 5V signals whereas the MiniSharc expects 3.3V levels on I2S.
It looks like this board outputs 5V signals whereas the MiniSharc expects 3.3V levels on I2S.
No, I use this board:
audiophonics xmos interface usb vers i2s 24bit/192khz
Maybe it is based on the same chip.
I wire also the GND btw the minisharc and xmos (however nothing changes whe I disconnect it.
The minisharc is running in Input Slave/Output Master mode and it uses an ASRC on the input. As I said, after start-up procedure it runs. Yesterday I have watched 2 movies and listened several CD´s on it.
I red in the MiniSharc manual that in Input Master(default mode) mode the LRCK and the BCK are outputs, maybe during startup it sends some signal to this pins until it switches to Input slave mode and it causes a problem. But I think MiniDSP can not make this mistake.
Frank
audiophonics xmos interface usb vers i2s 24bit/192khz
Maybe it is based on the same chip.
I wire also the GND btw the minisharc and xmos (however nothing changes whe I disconnect it.
The minisharc is running in Input Slave/Output Master mode and it uses an ASRC on the input. As I said, after start-up procedure it runs. Yesterday I have watched 2 movies and listened several CD´s on it.
I red in the MiniSharc manual that in Input Master(default mode) mode the LRCK and the BCK are outputs, maybe during startup it sends some signal to this pins until it switches to Input slave mode and it causes a problem. But I think MiniDSP can not make this mistake.
Frank
Even if MiniDSP made such error in the firmware it still should not bring down the USB I2S bridge. As the XMOS chip functionality (USB to I2S) is also defined thru firmware the error could also exists here.
I have made an I2S isolator board, connected it btw. XMOS board and miniSharc and it works. Hopefuly the problem is solved.
Thank you for your help.
Frank
Thank you for your help.
Frank
Happy for you that you found a workaround with an isolator (IL715?)
Given the solution it seems like it maybe is/was some issue with power or ground levels that prevented the USB I2S XMOS device to boot.
Now both grounds are no longer connected you could maybe measure a voltage/potential difference between the 2 grounds.....that could hint at such problem.
Given the solution it seems like it maybe is/was some issue with power or ground levels that prevented the USB I2S XMOS device to boot.
Now both grounds are no longer connected you could maybe measure a voltage/potential difference between the 2 grounds.....that could hint at such problem.
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