I stream from the same server (STi5) + uR and the ripped files from CD do not sound as good as the ones through Tidal. This is frustating as I've got hundred of track that are not available on Tidal. Is it because they are stored in a USB Hard Disk? Shall I nuy a SSD to store the files. Will they sound better? Shall I buy NAS? Any help will be appreciated. Thanks.
A good starting place is by understanding what do you mean by better?
I will start by using a simple example.
When I started using the Mojo, I used both the usb input and the optical input.
With optical the music/vocals was very clean and pure.
With usb the music was very clean and pure, but sounded slightly brighter. I added a ferrite choke to the usb cable, to remove any RFI that was being picked up, but some of the brightness still remained. That extra brightness was caused by the residual electrical noise from the computer internals, travelling through the usb cable, and entering the mojo internals.
Some people prefer the more realistic sound quality from using the optical input, but others prefer that false brightness created via the residual electrical noise.
There is no right or wrong answer, because so much depends on peoples preferences.
It is possible that there is little that you can do, to reduce any residual electrical noise from your server, reaching your dac.
However there is a simple experiment that you could try. Some owners who only have usb outputs on their computer, buy a usb to optical converter from amazon, and use that to discover if they prefer the sound, when using the optical input.
Little explorations like that, can help owners understand what they want to achieve, and possibly steer their route to achieve it.
It is certainly cheaper than rushing out and immediately buying SSD drives.