Amanero or Xmos USB to I2S converter to Hypex PSC 2.400d (DSP2W)

[bavmike]

Hello, I am pulling my hair out trying to connect either my Amanero or my XMOS USB to I2S converter to I2S header on my Hypex PSC 2.400D DSP plate amp.

I'm pretty sure it can be done some how. The biggest problem I seem to be facing is in order for the Hypex DSP software to show the option of a digital input, the AES/EBU board needs to be connected. I'm sure there's a way I can fool the DSP board into thinking the AES/EBU board is connected though.

I am attaching some pics of the DSP board header, AES/EBU board and the header pin layout from the DSP2W datasheet.

Another thing is I'm not sure which pin to connect the FSCLK on the Amanero to. Hopefully one of you digital gurus can help me out.

Thanks in advance

 

[Hsmeets]

Most likely the hypex will communicatie with the aes board via the i2c sca/scl lines to detect the board and set/get the operationele mode of the aes board. You need to know the protocol and hypex likely Will not disclose.

 

[bavmike]

Most likely the hypex will communicatie with the aes board via the i2c sca/scl lines to detect the board and set/get the operationele mode of the aes board. You need to know the protocol and hypex likely Will not disclose.

I managed to get the green light to pop up indicating a digital signal was detected in the Hypex software, when I connected the DATA and I2SCLK wires to the pins on the backside of the box header of the AES/EBU board.

Maybe I can leave this board plugged in and solder some pins to the back side of the box header. I'm just not sure which pins I will need to connect and where.

On the AES/EBU board, after the inputs the signal goes through a digital chip. I imagine this chip decodes the digital signal back to I2S to be sent to the main board. So if I let the board do what it does to allow the main board to accept the signal, it just might work.

I don't want to fry my Amanero in the process though.

 

[Hsmeets]

I think there is fair change of frying the electronics, maybe not within a minute...but eventually as you tie two i2s outputs together and have no clue how electronics behave under that situation.

There is also the Sample Rate Conversion you need to take care of, if i'm not mistaken seeing your pictures the IC on the EBO/AES pcb is an SRC4293 that amongst other takes care of this. Given that de clock on the connector is output it indicates that you need to run the USb-I2s interface likely in slave mode. The DSP inside de plate amp runs at (if not mistaken, 48Khz) and all input needs to be resampled to that (hence de 4392 on the EBU/AES board). AFAIK the two mentioned USB to I2S bridges don't do sample rate conversion.

There also the question what I2S format is used by Hypex: Philips, Left-Justified, etc....

 

[bavmike]

I think there is fair change of frying the electronics, maybe not within a minute...but eventually as you tie two i2s outputs together and have no clue how electronics behave under that situation.

There is also the Sample Rate Conversion you need to take care of, if i'm not mistaken seeing your pictures the IC on the EBO/AES pcb is an SRC4293 that amongst other takes care of this. Given that de clock on the connector is output it indicates that you need to run the USb-I2s interface likely in slave mode. The DSP inside de plate amp runs at (if not mistaken, 48Khz) and all input needs to be resampled to that (hence de 4392 on the EBU/AES board). AFAIK the two mentioned USB to I2S bridges don't do sample rate conversion.

There also the question what I2S format is used by Hypex: Philips, Left-Justified, etc....

Well sounds like I'm better off giving up on this mission by the sound of things.

The reasons I'm trying to do this in the first place are

1: Avoid the need for a USB to AES/EBU converter.
2: Avoid the jitter introduced in the process of converting to AES/EBU and back to I2S
3: Have a very short direct signal path from the Amanero to the DSP board.

I suppose the biggest bottleneck in the system is the DSP chip and onboard DACs themselves. In the end this may be overkill.

What I'll probably do now is pull off the DSP board altogether, and replace with high quality DAC modules. I'll do my DSP in the software instead.

 

[bavmike]

Only problem with this is I'll need a multichannel USB to I2S converter. Only one I know of currently available is the Rigisystems USBPAL now that the EXAu2i has been discontinued. And I'm not sure if the quality of that unit is on par with the EXA.