AKG BAP1000 Digital IO

[rfbrw]

No need to make any changes to the DIR board. Just set to I2S. MCLK not needed.

 

[huelskemper]

Great!

 

[huelskemper]

Hi,

I hope you are doing well.
The CS8421 board arrived (really tiny).

I am curious what to do next.

 

[rfbrw]

No changes to the input side. On the output side two resistors have to change.
Resistor 1 . 4K02 to 16K2.
Resistor 2 . 1K96 to 1K.

 

[huelskemper]

Thank you so much!
Nice task for the weekend.

 

[rfbrw]

No problem. It is all good fun. If you have any problems let me know.

 

[huelskemper]

Resistors are changed and wiring is done...do I have to lift some pins of the CS5338 ADC not to damage it? Not sure if he likes to get signals on the output...

 

[rfbrw]

It is best to lift the CS5338 pins. If the ADC output pins are at 0v they will pull down anything connected to them. You could also connect APD and DPD to 5v. This will power down the analogue and digital sections of the ADC.

 

[huelskemper]

I lifted the CS5338 pins (and ripped the BCK pin off ).
LED on CS8421 board shows "locked".
BCK and L/R signal unchanged but DATA is now at only 88kHz instead of 705.7kHz prior.
Analogue output is only garbage.
Feeding the DIR9001 board with a sine wave (via TOSLINK) does not result in anything sine wave kind at the output.

Any idea?

 

[rfbrw]

The DIR9001 input will only respond to a SPDIF encoded signal even over Toslink. And the output will also be digital. Have you anything with digital audio. It can sometimes be used for testing.
On the output side of the CS8421 BCK and LRCK are inputs. When the input side is ok the left led is blue.

 

[huelskemper]

Yes, I used a SPDIF signal from my PC (external USB sound card with TOSLINK out), but the DATA input signal for the BAP1000 did not change if signal was applied yes or no.
BCK and LRCK (coming from BAP) signals are as before: 2.8 MHz and 44.1kHz. Only the DATA signal is different.
The CS8421 board shows red light on the "locked" LED. DIR9001 board is set to I2S out.

 

[rfbrw]

My board has two blue leds. Have you got a picture of your board ?

 

[huelskemper]

sure.

 

[huelskemper]

while startup first the left (unlocked) then the right (locked) LED is on.

 

[rfbrw]

1. As connected in the picture the unlock led locks with a SPDIF input signal ?
2. On the ADC are pins data, bclk and lrclk all lifted ?

 

[huelskemper]

correct. DATA pin even ripped off...

 

[rfbrw]

How long are the wires for bclk and lrck from the AKG ?

 

[huelskemper]

about 5cm...

 

[rfbrw]

Have you got a GND wire on the output side ?

 

[huelskemper]

I have connected the DGND of the BAP1000 to the CS8421 board output and routed it to the DIR9001 (from CS8421 input connector)