Gents,
My understanding is
audio on
YouTube is
compressed and therefore not suitable for a real audiophile to use for testing purposes. I suspect the same is true for an
Audioholic .
IMHO the type of source material (or container if you will) is almost as important as what material is used. It should be various tunes well known to the listener, and hopefully heard numerous times before on a "good" system. Shy away from MP3s and the other Lossy formats; and stick to CDs, BluRay Concerts, and FLAC Tunes from decent source material. A FLAC tune from an MP3 is only as good as the MP3. The same holds true for FLAC tunes Ripped from Vinyl.
I hope this is helpful.