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-   -   Is this kind of PSU normal in a CD player? (http://www.diyaudio.com/forums/digital-source/33265-kind-psu-normal-cd-player.html)

Bricolo 30th April 2004 05:02 PM

Is this kind of PSU normal in a CD player?
 
2 Attachment(s)
That's how my CD player's PSU is
The transformer has only one secondary winding, with multiple voltages. So the current of the +-15V (analog) is shared with the digital ones, and the opposite too.

jean-paul 1st May 2004 08:42 AM

Unfortunately this is standard practice with some brands, you'll probably see the benefits of separate windings now.

In this case adding a small transformer can do wonders.

Bricolo 1st May 2004 01:34 PM

Unfortunately, those Philips/Marantz transformers are only a part number, no other info on that.
So I have no idea about the VA rating I should use as a replacement

Is there a way to calculate the VA? Maybe with the winding's resistance...

Andypairo 1st May 2004 01:37 PM

You can compare the size with other transformers of known rating for example... my CD player's trafo is surely no more than 30VA...so...oversizing your replacement trafo a little won't be that hard (nor particularly expensive)

Cheers

Andrea

Bricolo 1st May 2004 03:58 PM

2 Attachment(s)
What would you say? 30VA too?

I had another idea that xhanging the transformer: using a second one only for the analog PS (+-15V)
So the "2nd wires from gound" on the secondarie would be unused on the first transformer. Or is the VFT power supply more harmfull for the digital that the digital is for the analog?

Fin 4th May 2004 02:48 AM

Similar layout - similar idea!
 
Hi Bricolo

The power supply in your CDP (CD62???) looks the same as that used in my CD624.

From what I can tell, the +/-15V only supplies the output opamps and there is a -15V going to the Kill circuit.

The +/-5V supply feeds all of the other ICs including the decoder and dac.

The +/-10V supply feeds the servos.

I have thought of adding a new 25-30VA transformer to supply the +/-15V for the opamps and the +5V for the DAC/filter and decoder.

The original +/-15V supply could then be used as a pre reg for the main -/+5V supply, with the added benefit of moving the +/-5V supply further away from the +/-10V servo supply.

I haven't tried any of this yet, but I think it is possible and might be worthwhile.

Fin 8th June 2004 07:50 AM

Bricolo

Have you had any progress here?

Bricolo 8th June 2004 02:08 PM

nope, I haven't worked on the PSU now.
I'm trying to have Rudolf's super pair I/V working:smash:

Fin 9th June 2004 12:03 AM

I'm busy collecting info on it now - so when you get there, let me know.


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