The BCLK or DSD CLK digital waveform looks like a fixed frequency square wave.
The left and right channel data waveforms vary with time according to the music waveform. They appear on the I2S bus lines sometime called DATA and LRCK. For one example, when a fixed frequency sine wave is played it might look something like the green trace below on a scope:
There is also a repeating pattern kind of like the above that is an 'idle' or 'zero' waveform that is used when no music is being played. IIRC an 'idle' or 'zero' pattern never has more than two short pulses in a row before a long pulse occurs. So if you see three or more of the shortest time duration positive-going pulses in a row before a longer duration positive pulse occurs, that would tend to indicate its not an idle pattern, so its probably music. Again, this is from memory so it could be wrong.
Also, if you have a digital scope it may be easier to see what the waveform looks like if you reduce the horizontal sweep frequency so you can see a lot of digital pulses on the screen. Then press the 'stop' acquisition button on the scope to show the last horizontal sweep more clearly. You may need to start acquisition again with a slightly different sweep rate if you see too many or not enough pulses after the acquisition is stopped. May take a few tries to get a good sample of pulses on the screen.
The left and right channel data waveforms vary with time according to the music waveform. They appear on the I2S bus lines sometime called DATA and LRCK. For one example, when a fixed frequency sine wave is played it might look something like the green trace below on a scope:
There is also a repeating pattern kind of like the above that is an 'idle' or 'zero' waveform that is used when no music is being played. IIRC an 'idle' or 'zero' pattern never has more than two short pulses in a row before a long pulse occurs. So if you see three or more of the shortest time duration positive-going pulses in a row before a longer duration positive pulse occurs, that would tend to indicate its not an idle pattern, so its probably music. Again, this is from memory so it could be wrong.
Also, if you have a digital scope it may be easier to see what the waveform looks like if you reduce the horizontal sweep frequency so you can see a lot of digital pulses on the screen. Then press the 'stop' acquisition button on the scope to show the last horizontal sweep more clearly. You may need to start acquisition again with a slightly different sweep rate if you see too many or not enough pulses after the acquisition is stopped. May take a few tries to get a good sample of pulses on the screen.
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Well then, maybe you should care? If think you are playing music and what your scope shows is a DSD idle signal then you may as well have no signal at all, because you won't have any sound. The idle signal is only to keep the output the DAC at zero volts rather than hitting the negative rail. It means the scope would be indicating you have a problem before the DAC. It can happen 
For most purposes I2SoverUSB may be favored over Amanero. It features galvanic isolation, and NDK SDA clocks. http://jlsounds.com/#:~:text=I2SoverUSB v.,up to 32 bit resolution.
The Amanero has recently been updated & now also offers S/PDIF in and out.
I have tried all the other boards & still find Amanero the best.
Dom provides excellent support, build quality is top notch & the firmware tools make it very flexible.
I use the Amanero board in DAC's I manufacture & find them extremely reliable.
For the record I have no financial connection with Amanero just a very happy customer
I have tried all the other boards & still find Amanero the best.
Dom provides excellent support, build quality is top notch & the firmware tools make it very flexible.
I use the Amanero board in DAC's I manufacture & find them extremely reliable.
For the record I have no financial connection with Amanero just a very happy customer
Have also used Amanero with dedicated 5v power instead of USB power. The mod helps a lot. Thank you @clay-speakers for pointing that out
However, I still find that galvanic isolation makes an audible difference when using large panel ESL speakers.
To illustrate, not long ago we had a visitor who summarized later as follows: "Listening to your systems, the main thing I notice is the speakers. They are extremely low distortion, resulting in a lot of transparency and ability to hear down into the preceding components. Also, the ability to play really loud and clean is astonishing..."
For me what it means is, just gotta be very picky about all components in the system. It can be a pain at times, but the system is used to nitpick over all sorts of little audible issues. Could be most people wouldn't care about most of it. Just kinda what we do around here, is all.
However, I still find that galvanic isolation makes an audible difference when using large panel ESL speakers.
To illustrate, not long ago we had a visitor who summarized later as follows: "Listening to your systems, the main thing I notice is the speakers. They are extremely low distortion, resulting in a lot of transparency and ability to hear down into the preceding components. Also, the ability to play really loud and clean is astonishing..."
For me what it means is, just gotta be very picky about all components in the system. It can be a pain at times, but the system is used to nitpick over all sorts of little audible issues. Could be most people wouldn't care about most of it. Just kinda what we do around here, is all.
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