I`m on the way soldering my Buff III together.
Since I want to minimize interferences I`m trying to mix power grounds as less as possibe.
So, six separate pre-regulated supplies instead of one common prereg (one additional for powering sidecar, spdif board and teleporter) will feed the whole thing.
I disconnected the 5 reg inputs from the +VD plane and connected them separately.
Since also the sidecar doesn`t get his power over the +VD plane, I think that there is nothing more connected to it
(am I right?).

Now my somewhat unusual question:
Since the +VD plane seems loose now, can I connect it to ground?
This shouldn`t be a bad thing since there would be an additional ground plane, shielding the DAC.
Could this be done?

Edited by user Wednesday, August 15, 2012 9:28:39 AM(UTC)  | Reason: Not specified

Yes, I`m on my own
Despite of that, it makes me thoughtful when you Russ, as one from the creators of the Buffalo wouldn`t do it.
I`ll leave it floating for now, checking out how the other components work together.

Thanks, Marcel

Sure it has.
It is very practical for directly tapping power lines.
Furthermore I think, the different power currents take the shortest way to their dedicated places (in this case the five parallel-reg input tappings), like return currents in a ground plane do.
Or is there another, maybe secret reason (you arouse my curiosity)?

I`m wondering...
I`m not a RF-specialist but until now I thought, that shielding has very little to nearly no effect on external common mode noise.
I suppose, that common mode noise (and I mean also the internal one) is more or less unavoidable in a digital circuit with such a high clock rate.
Now, even with differential circuits (as the sabres integrated analog sections probably are, but not the oscillator and a big part of the main digital stages), the RF-energy is capacitively coupled trough the regulators and not supressed!
In the worst case, the shield (plane) is radiating noise itself, which is often true.
Embedding planes like your ground could be a cure to some degree.
Isolating every reg with its own choke or current source (your parallel regs surely have some in series) and additionally supporting every reg with its own supply like I`m trying to do shouldn`t be a bad thing neither and in theory has some further benefits.
Please, correct me if I`m wrong...

Mmmmh, think I mixed things and departed myself from my original intention.
Don`t take me wrong Russ, I`m far from critizising your design.
It`s surely well-tought-out, high quality (never had such a sturdy board in my hands) and from what I heard and read very good sounding.
I`m really curious, how it will do with the separate supplies (and maybe the grounded power plane)
Still have some soldering work left...

Thanks for your patience and your openness
Marcel

Edited by user Saturday, August 18, 2012 12:28:46 PM(UTC)  | Reason: Not specified