Power-supply and DAC : 2 cabinets ?

Eldam

Banned
2012-09-13 12:25 am
France
Hi,

My DAC has 5 R-Core power supplies !

I have around 15/20 cm of wire between them and each diodes bridges.


Is it usefull to "isolate" the active circuits from the C-Cores PS ?
They have a primary-secondary isolation with a yellow wire.

Need I to put them in a separate box in ferite material from the DAC cabinet or does it not matter ?

If yes, are the thickness of walls enclosure and proofness of the cabinet important ?

What should be the max length between the secondaries and diodes bridges if matters ?

Thanks for your help
 
You need to keep the charging pulse loops as small as possible. That means transformers, rectifiers and reservoir caps as close together as possible, with twisted pair wiring between them. After that things are less critical.

About the worst possible option is to put the transformers in one box and the reservoir caps in another box. In that case it doesn't matter which box you put the rectifiers in, as the outcome will be bad either way.
 

Eldam

Banned
2012-09-13 12:25 am
France
Ahaha, I like a lot the point 2 : that's why I make in life most of the time ! Even in a conversation during a dinner if more than one personn is agree with me I'm asking myself if I'm not a fool !

@ Marce : unluckilly it's not a design from scratch : it's the AYA II TDA1541A board which sound good very good to my ears after some "mods" (oh no !)...(btw it sounded already good before !)

According to you : will I hear a difference if I get closer the C-Core to the diodes bridges by making shorter the secondaries wires ? e.g. 5 cm instead the 15-20 cm distance ? Do I need a minimum shielving or screw each C-Core at 160° from the other one near it to minimize "bad" EMC ?? (no problems if C-Core are close to each others ? I screw their primary/secondaries shieldings yellow wire in the metal case in a star configuration ? - unluckilly I have no earth in my living room ! )
 
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Eldam

Banned
2012-09-13 12:25 am
France
picture for the fun and to make you laugh !


I have to learn to draw...
 

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Eldam

Banned
2012-09-13 12:25 am
France
Is it Worthing to turn each C-Core 160° from each other for EMC ?

Or putt a 10 cm height aluminium wall just before the pcb (bridges) when C-Core are close (less than few 2 or 3 cm) ?

About the vibrations of PS traffo ? Is it a myth as well or do I need to isolate them by screwing on a wood pannel for instance to cancel vibrations :eek: ?

Btw the main pcb is isolated from the case by plastics pins and double side scotch-tape !
 
Is it Worthing to turn each C-Core 160° from each other for EMC ?
I don't know.

Or putt a 10 cm height aluminium wall just before the pcb (bridges) when C-Core are close (less than few 2 or 3 cm) ?
No. Aluminium does not stop low frequency magnetic fields.

About the vibrations of PS traffo ? Is it a myth as well or do I need to isolate them by screwing on a wood pannel for instance to cancel vibrations
Some mains transformers vibrate. Putting them on a wooden panel is likely to make the noise much worse, as the wood acts as a sounding board. Use flexible mounts, such as grommets.