Remote power supplies

[karatestu]

The resistance of the supply cable need not be significant depending on the gauge of cable used but, with the final smoothing capacitor/s in the equipment case the capacitance of the feeder must be considered too. I suspect however that a power supply with a large capacity, beyond that required to power the equipment, will have a greater effect on the sound than will the feeder cable or the location of the final smoothing capacitors.

Thanks for your input Geoff.

I refer to the following thread from nearly two years ago. My post (no.2) and the doc's (no.3).

viewtopic.php?f=29&t=48816&hilit=distance

[Geoff.R.G]

The resistance of the supply cable need not be significant depending on the gauge of cable used but, with the final smoothing capacitor/s in the equipment case the capacitance of the feeder must be considered too. I suspect however that a power supply with a large capacity, beyond that required to power the equipment, will have a greater effect on the sound than will the feeder cable or the location of the final smoothing capacitors.

Thanks for your input Geoff.

I refer to the following thread from nearly two years ago. My post (no.2) and the doc's (no.3).

viewtopic.php?f=29&t=48816&hilit=distance

Then I will refer you to my post (nr 4) in the same thread.

[Geoff.R.G]

Stu, my observation, based on the Phono 2 design with separate PSUs for each stage of amplification, is simply that a bigger power supply will have more effect than will the cable (length wasn't what I meant). 30cm or 60cm of feeder from a PSU to an Amplifier won't make much difference in terms of resistance, especially if you use a bigger cable for the longer distance.

It is apparent from user reviews of the Phono 2 that PSU capacity can be a limiting factor, the Phono 2, having two PSUs doesn't have that problem.

[karatestu]

Hi Geoff. Thanks for your observations.

In your first post of this thread what did you mean by "capacitance of the feeder" ?

[montechristo358]

apologies for the thread hijack Stu, but seemed the logical place

I've read several times about keeping the BMU well away from the sources if possible. How about separation from remote PSUs? Necessary? Desirable?, or no real difference?

Having a kit reorg at the moment and whilst a good distance between source and PSUs is achievable, separation between PSU and BMU is a bit more challenging

[karatestu]

Hi Monte.

When i messed about with transformer placement i did think the sound was better when a transformer had some distance from other transformers. But it was no where near as important as distance to amplifier and regulator boards.

If you can experiment with the bmu in a temporary position which is further from the psu's and see if the music improves. That is the only way to know for sure. The bmu transformer is 1000VA so a bit of a monster and emi gets worse as transformers get bigger.

[Geoff.R.G]

Hi Geoff. Thanks for your observations.

In your first post of this thread what did you mean by "capacitance of the feeder" ?

Stu, If you take a piece of two core cable say 1m long it has resistance and capacitance. Any two conductors running parallel to each other for a, small, capacitor. So, if your feeder from your PSU to an amplifier is a two core cable you have added some capacitance. Depending on the value of the final smoothing capacitor, the capacitance of the feeder will normally be insignificant. It would however be remiss of me not to mention it.

Obviously if you run well separated -ve and +ve wires the capacitance will be insignificant.

[karatestu]

Thanks for clarifying that Geoff. I couldn't work out if you meant the cable or the first smoothing capacitor which would be local to the transformer and rectifier.

I think the psu for the nva phono 2 has only one cable so the wires must be all together in a bundle. Knowing Doc he would probably have gone for untwisted to keep the capacitance as low as he could. Or maybe not. In my build i am going to house everything in a cabinet much like a sideboard so i have a more scope to put a bit of distance between the wires (positive, negative and 0V).

[Lurcher300b]

so i have a more scope to put a bit of distance between the wires

Just be aware that the larger the distance between the wires, the larger the area you are creating that can act as an aerial. There is a reason for keeping the wires together and twisted.

[karatestu]

so i have a more scope to put a bit of distance between the wires

Just be aware that the larger the distance between the wires, the larger the area you are creating that can act as an aerial. There is a reason for keeping the wires together and twisted.

Hi Nick. Thanks. Yes i was aware of loop area but i always (rightly or wrongly) try it Doc's way first and if it does pick up noise then i do something about it.