UcD400 Q & A

[lne937s]

Thanks,

I went ahead and already bought the second pair.... should be good for when the UCD700 comes out. I'll have to look into the capacitor setup you are suggesting- seems interesting.

Best,
Larry

[DSP_Geek]

If you're just starting out, I'd recommend investing in a good DVM. There are some nice little Chinese jobs which have the same feature set as a Fluke for about one-third the price, good enough for light duty.

You can try simulating your supply with this:
http://www.duncanamps.com/psud2/
which will give you a decent idea of what to expect.

You also have a goodly amount of filter capacitance, so you might want to look into a soft start circuit to reduce your inrush current. Your rectifiers and capacitors will thank you.


Cheers and happy soldering,
Francois.

[WJMackintosh]

[QUOTE]Originally posted by ewildgoose
[B]I have a couple of UCD400s and also some Zappulse. So the other day when I realised that it's impossible to get reception on my FM radio placed in the front room I initially suspected the Zappulse... Turned that amp off and still I could barely get recption... Turned off the UCD400 amp and .... reception back to normal..

Can someone recommend an appropriate ferrite from farnel or RS that should do it? Can I get away with popping the ferrite around the wires inside the amp case? (Do you need a complete loop around the ferite or does it just clamp on?)

Hi Ed,

I have just finished fitting split ferrite cores to the outputs of a pair of ZapPulse modules that I recently finished. I can now report that my FM tuner is still unusable and there are still interference patterns on my TV. I will have to fit longer wires to the outputs to allow me to put another turn through the cores.

I am surprised there has not been much discussion on this subject on this forum and that there is no reference (to my knowledge) to the potential of this sort of problem on the Hypex or LC Audio websites.

Regards,
Bill

[Jan-Peter]

Originally posted by WJMackintosh;

I have just finished fitting split ferrite cores to the outputs of a pair of ZapPulse modules that I recently finished. I can now report that my FM tuner is still unusable and there are still interference patterns on my TV. I will have to fit longer wires to the outputs to allow me to put another turn through the cores.

I am surprised there has not been much discussion on this subject on this forum and that there is no reference (to my knowledge) to the potential of this sort of problem on the Hypex or LC Audio websites.

This is a very difficult topic for SMPS and Class-D amplifiers. In the second version of the UcD400 we have solved this matter to a very low level of EMI by improved PCB design and a new design of outputcoil.

With a good setup (metal case) you can use your FM tuner in combination with the UcD400.

Regards,

Jan-Peter

[peranders]

Just curious Jan-Peter, but do you have any EMC measurements(*) over your modules in a typical setup or even a typical DIY setup?

*) Which you want to share.

[tiki]

Hello Jan-Peter,

is it possible, to share the advanced output coil data with us? So anybody, who bought an early UcD180 or UcD400 could change his coils to prevent from these interferences, if necessary.
Second question: Was it possible to lower the output coil temperature of the UcD400 by the new design?

Thank you in advance,

Regards, Timo

[Jan-Peter]

Originally posted by Peranders;
Just curious Jan-Peter, but do you have any EMC measurements over your modules in a typical setup or even a typical DIY setup?

We have an Advantest R3131A Spectrum Analyzer (http://green.advantest.co.jp/techinf.../R3131A_e.html) with a Current Clamp.

Originally posted by Tiki;
is it possible, to share the advanced output coil data with us? So anybody, who bought an early UcD180 or UcD400 could change his coils to prevent from these interferences, if necessary.
Second question: Was it possible to lower the output coil temperature of the UcD400 by the new design?

It's not possible update the outputcoil with this newer coil. The size and connection is completly different, so it will NOT fit in the PCB.

The EMI of the UcD180 and UcD400 is below the official limits. If you still have problems and like to reduce the EMI you can always use a ferrite clamp and ofcourse a good metal case.

Actually the EMI of the new version of the UcD400 is a little bit ABOVE the noise level of the Advantest R3131A.......

Jan-Peter

[tiki]

Hello Jan-Peter,
please excuse me, if I'm annoying you.
Was it possible to lower the UcD400 output coil temperature by the new design?
Thanks, Timo

[Jan-Peter]

...hm, the outputcoil temperature is no problem in every UcD version. There are already more as >1.000.000,00 channels produce with the same coil as in the UcD180. When this is not ok, Philips would changed this, don't you think so??

Besides this the new coil on the UcD400 is indeed reduced in heat, hower that was not the reason for this new coil. Philips has designed this new coil for more outputcurrent and lower EMI.

Regards,

Jan-Peter

[IVX]

There are already more as >1.000.000,00 channels produce with the same coil as in the UcD180.

Jan-Peter, it's unbelievable!! 100 millions UcD's which have the same coil, and seems there is some quantity with other coils.. Where is this ocean of the UcD's, on the stock? All this UcD's put one by one, would be way from you to me and back again, i'm sure..
100000000 pieces it isn't wrong?