How do I make a high-quality stereo master?

I have so far been able to “record” (save) Ardour files/projects to disk, but obviously this is a bulky and ‘proprietary’ format.

Up to now I have simply connected the master-output to the D/A Outputs for monitoring.

I suppose I could either take a ‘digital out’ (SPDIF?) from an appropriate card,
or else pump the output into an external third-party tape unit to make an analog stereo master tape.

But surely this may be adding processing and noise, and deteriorating the signal.

Ideally I would really want to pump the output of Ardour’s master tracks directly to disk,
in the highest sample-rate/quallity possible.

It isn’t intuitive how I would do that:
Is there a 3rd-party piece of software that is the default recommended method?

What should I be running, in order to produce a high-fidelity file I can play back with Alsaplayer or share with friends?
What is the best format for such a file? I am thinking gathering songs to later burn a high-fi audio CD.

Any hints or recommendations?

@nazaroo2

I have so far been able to "record" (save) Ardour files/projects to disk, but obviously this is a bulky and 'proprietary' format.

Not sure why you think WAV is a proprietary format, it is pretty much uncompressed PCM audio with a header describing it, and fairly standard.

Ideally I would really want to pump the output of Ardour's master tracks directly to disk, in the highest sample-rate/quallity possible.

Export or Bouncing, either of these will do this. Bounce will use the same sample rate and bit-depth as the rest of your project so no dither or sample rate conversion is needed, and will just create another file in your audiofiles folder that you can put anywhere in the same format as the rest of your session, either WAV or BWF, whichever you are using.

Export gives you the option to do sample rate conversion and dither if it is needed. The sample rate conversion is pretty high quality, I don’t have complaints about it, but take that as you will.

What should I be running, in order to produce a high-fidelity file I can play back with Alsaplayer or share with friends?

Ardour. That is all you need for this.

What is the best format for such a file? I am thinking gathering songs to later burn a high-fi audio CD.

Depending on what you mean by ‘high-fi audio cd’ will determine the best format. If you mean a standard red book CD, or something similar(As many CDs these days aren’t technically red book) then an uncompressed PCM 16 Bit/44.1kHz file is ideal, applying sample rate conversion if appropriate to change your sample rate to this and dither. If referring to SACD or similar the answer is different, but I don’t mess with SACD much and apparently it uses DSD, the merits of which are debatable compared to PCM.

Ardour has a capability of exporting TOC or CUE files along with the audio file, which can be very good for creating a CD as it allows you to define what the tracks would be and the space between them in a linear fashion on your timeline using CD ranges. If you are exporting for burning to a standard audio cd, this is worth looking into.

Seablade