Glad the cable thing got sorted out. There are very good, professionally made digital coaxial cables on the market (don’t worry about gold connectors though) that don’t cost a fortune. So if you dread working with small pliers, soldering irons and such, just buy a pair. Tip: the ones you find in the box with some home-grade stereo setups are NOT the right ones 😀 .
On the bigger question: what makes digital digital and different from the analogue RCA sitting next to it?
Good question and hopefully I an answer it in a comprehensible way without going my trademark wall-of-text, LOL.
Whether you use CDs,USB-sticks, streaming audio, whatever, it all starts as digital music. CDJs, controllers, iPhones all are able to “read” digital music. Most devices will manipulate the music in it’s digital form before offering it to a DA-converter (Digital to Analogue). It is at this point that sound goes from being written in zeros and ones to actual analogue (varying voltage) sound. Speakers and headphones need analogue input to be able to correctly translate electronic analogue signals to audible output our ears can process.
Many modern mixers and certainly all controllers do their sound processing digitally. At the end they too need to DA convert to get audible sound eventually.
In your typical CDJ/mixer setup this would be the signal path:
* digital source (CD/MP3, etx.)
* processing inside device
* DA conversion to analogue signal on RCA
* RCA to mixer analogue input (also RCA)
* AD (Analogue to Digital) conversion of incoming signal (so you can use all those nice digital FX and EQ in your mixer)
* processing inside mixer
* DA conversion to analogue master output on mixer
* Analogue signal to speakers
As you see this can lead to 3 DA/AD conversions which is something you really don’t want if possible. Another thing is that there is not option for error correction with analogue signals as the receiver of that signal has no means to double-check if what it received is the way it should be. Digital signal do have error correction (usually checksum).
Analogue signals are also much more prone to outside influence which create actual audible noise or drop-outs. Digital signals carrying only 0 and 1 as information are much harder to disturb and with the error correction have a far better chance of being restored on the receiving end.
So let’s do the same gear as above but now digitally connected:
* digital source (CD/MP3, etx.)
* processing inside device
* digital sound through coaxial output/cable to mixer
* processing inside mixer
* DA conversion to analogue master output on mixer
* Analogue signal to speakers
As you can see, there is only one DA conversion left, at the end of the sound chain before it goes out to the speakers.
So, if both your devices and your mixer support digital connections you should use those for better sound quality (every conversion hurts the signal quality some, depending on the quality of the converters it will be more or less) and lesser chance of outside influence due to the environment (old lighting dimmer packs for example are notorious for their influence on nearby signal cables).
Hope that helps some.
.
