At Alpha Audio we regularly dive deep into the abyss of technical complexity. Think about investigating power conditioners, cables and of course: the network. In this episode of Alpha Labs, we’re going to look at how noise over the network affects the clock in your streamer. Nerdy? Yes… but we like that!
We pulled out quite a bit of gear for this episode of Alpha Labs. It also takes quite some stuff to do this measurement. First, we need a realistic scenario where it becomes clear how noise across the network can affect playback. For that, we grabbed the Volumio Primo. A nice streamer where we can also easily get to the clock. This clock times the d/a converter chip. In short: jitter on the clock directly affects playback.
To measure the jitter we need the Wavecrest SIA-3000. We take a Rohde Schwarz probe (X10 / 300 MHz bandwidth) and a Matthews impedance buffer to get the clock signal into the Wavecrest.
On the network side, we have a CDN – coupling / decoupling network – to isolate the network as well as to show the noise. The RF port on the CDN goes directly into the spectrum analyzer. This allows us to see how high the noise is that we are dealing with.
We manipulate the noise very simply: we have a current probe into which we can put white noise and we have a switch mode adapter that we place next to the network cable. The result is immediately visible on the spectrum analyzer. Finally, we also have a “dirty switch” that we use to show you what this can do.
We hope this Alpha Labs gives some insight into this somewhat nerdy side of our hobby!