Audiolab 6000 transport vs vintage Sony

I have been using a Sony 608ESD CD player via digital out and was very happy...how could something that just put out a numbers stream affect sound? The Sony is old but it’s a digital stream...
But then I saw a post or two about how it could make a difference.Finally, after much forum lurking and review reading, I ordered a audiolab 6000cdt transport.
Got it yesterday, hooked it up and played a variety of music going back and forth with the Sony, just switching the toslink back and forth.
Fully surprised!
The audiolab provided more soundstage, better separation of voices etc, crisper- more defined bass and just more definition overall. No negatives.
A good example was on Hans Theessink and Terry Evans Visions, the track “ Talk to your daughter” their voices just separated and became singular and clear...
i thought going in that it might be a touch better at something and I was fully prepared to pack it up and send it back not being able to justify the dollar to sound improvement.
How is it possible for a digital stream to sound so different?

For reference my system is Vandersteen 3a signatures, Benchmark amp, Benchmark DAC3 hgc, Benchmark speaker cables....