Hi all, I’m very new to digital audio but have always loved good quality music. Recently I and a friend both set our hifi system but our approach to achieve better sound is very different. I studied computer communication in university so I don’t really believe in the metaphysical stuff.
I agree with my friend that everything after DAC is worth investing, they all significantly changes the sound. However, instead of buying fancier computers (or very expensive dedicated players) to feed the DAC, I went the Roon route. What I understand the player is decoding common music file format(FLAC, AIFF, or even MP3) to PCM streams and deliver it to the DAC(I’m not talking about DSD as I don’t have the source), The PCM is a unprotected bit stream works with a clock and then can be reformed to analog output. The main target to improve sound quality before the DAC is to guarantee the PCM is not broken before it enters the DAC. Even clock is not too much an issue here if the DAC is under USB async mode and uses its own clock. Can this task justify a multi thousand dollar spend? Not any computer can do this?
In Roon environment, the Roon core does the decoding part and put PCM into data packets under RAAT protocol and send over Ethernet to Roon endpoint. Personally I think the Core is not worth much investment as long as it can run the software properly. The decoding process is pretty error proof. The decoded PCM must be correct no matter how slow or noisy your computer is, just like a slow computer does not do the calculations wrong. This process does no effect on sound quality as the PCM before coding(the raw file the record company worked on) and after decoding are perfectly the same.
Then the core will pack the PCM into data packages under RAAT. I can’t believe this process or the RAAT data packages can be affected by your computer performance or noise otherwise the software should be able to verify and do this again. The procedure is not relevant to the clock as this is all done with the computer clock, there isn’t another clock to sync. Again, computer power isn’t much an issue here. Well, if you want DSP or other more complicated task it might be another story. But just keeping a bit perfect transmission, a moderate computer will do the task. I am using a Synology NAS. I believe it does the job.
Then Roon Core will send the packages to Endpoint. This process can’t go wrong either because it’s RAAT data packages being transferred. Roon Endpoint must have a way to verify the packages received are correct, or it will tell the Core to send the package again. That’s the whole purpose of the protocol. It doesn’t matter if the file is transferred through Cat cable or wif. Just like any other files you copy through cable or wifi are exactly the same. The endpoint only work with verified perfect files or it will stop working. The stability of the transfer route only affects how quickly the files can be transferred. If it is slow or interfered, the sound will be interrupted but not defected.
Then it comes to the key part, the endpoint. The endpoint will unpack the RAAT file and restore them to PCM data stream. Then it will send the PCM stream through USB port(or other interface) to DAC. This is where we want to spend money for better equipment as the PCM is only a stream of 1 and 0s and no body(DAC) can tell if it is correct or not. The noise the endpoint generates, from the power supply and on the connection to DAC should be reduced to ensure the 1s and 0s don’t get messed. The endpoint can be a very simple computer generates very little noise. I am using a microRendu and PSU and a fairly good USB cable to DAC. Minimizing the noise of the endpoint. The endpoint like MicroRendu will even reclock the file for better syncing with the DAC.
Above is my thoughts. In Roon environment only the equipment directly connected to your endpoint is worth heavily investing, because they might deliver noise to the output file. I did assume Roon, as a delicate music software, was designed to put sound quality on top priority, so there is ZERO error tolerance on the Core or the Endpoint to work on defected data. If your equipment is too wrong to do it, the software will just stop working and report error. Under this circumstance, Roon is extremely cost efficient as Endpoint is a simple computer not required to do much, it can be well protected from noise. Yes there are very expensive equipment can work as endpoint out there($X000), but that’s because they are sophisticated products themselves, not dedicate endpoints.