Internal versus External Clock

[fmak]

I am using a dCS upsampling system with 24/48 to 24/192 digital processor and twin cable 24/192 dac.

The input is digital radio on 24/48 with what looks like a decent clock supplied by a not so decent 7805 regulator.

With such a system, it is usual to run the processor synchronised to the input clock. Both the processor and dac connections have twin plls.

I am, however, finding a much better sound using the processor's internal VCXO clock. This gives a sound which is less bright and more musical.

Can electronics experts on this forum tell me why, and what is going on.

Note: On internal clock as sync source, my dac mutes 4 times as oppopsed to 2 whilst sync is taking place.

[A 8]

I am not familiar with the dcs gear but as you mention upsampling etc.....

I would think that the upsampler has a "new" master clock and reclocks so you should get cleaner (less jittery) clock pulses compared to using the input derived clock.
It may even be so that when you use the input clock you're not getting it upsampled to 192kHz.