UcD400 Q & A

[sx881663]

"I hate to be the party pooper but learning on the primary voltage is not a wise idea.

Before anyone plays with mains voltage they should have a TOROUGH understanding of electricity and electronics.

I fully encourage the learning and experimenting but not at the risk of personal harm."
rabstg

Sorry I don't understand your concern at this point. The mains connections have already been done and the discussion has all been about the secondary side of the transformers. I know we probably should have asked what protection he had implemented but this would have been off topic to his immediate problem.
No one advocates direct off line voltage usage that I have seen. What I have seen is the continued stressing of good safety practices in all ways.
ssanmor
Thanks for your response but I did solve my drawing problem. I do a free hand, scan it and then turn it over to my grandson to do his photoshop magic on. This is the really simple solution for me.
It would be real nice if there were a simple CAD type drawing program that had a good library of symbols to use. Of course this program would have to be able to output in the various formats and with selectable resolution. I don’t know of anything like this, do you?
Roger

[johnrtd]

We now also offer the Hypex modules. These are delivered as is (the modules) and as a complete kit including the power supply and the cabinet. Have a look at this picture http://www.hawkaudio.nl/amppic/kast-D-exploded-v.jpg for a two channel amp.
Also look at http://www.hawkaudio.nl

[ninjanki]

Hello everybody!

I've just finished building my first two UCD 400 monoblocks, and I have a few questions on my mind:

Why does one of the UCD Monoblocks get consistently hotter than the other? The hotter Monoblock seems to be always warm to the toutch,a nd I can feel this on both the module alum T as well as on the aluminium chassis it is attached. The other module, mounted exactly the same way, some times even feel cold, and I am sure both modules are working...


What should be the best sounding capacitor bank I could use? Right now I am using a couple of United Chemicon and Samwa 6800uF capacitors(4x6800 per UCD400), as well as one 100uF eletrolytic, a 470nF polypropilene and a snubber circuit(1ohm + 220nF) per rail.
I am wondering what would be, on your experience, the best main capacitors(Fische Audio, BC 154, BHC, Sikorel, etc...) and what should be the best topology for the other filtering components. I've remember reading somewhere that the extra small capacitors may not work very well with the UCD module, but that is in disagreement with all I've read about PSUs for audio...

Thanks,
Allan

[Leeuwarden]

Originally posted by johnrtd
We now also offer the Hypex modules. These are delivered as is (the modules) and as a complete kit including the power supply and the cabinet. Have a look at this picture http://www.hawkaudio.nl/amppic/kast-D-exploded-v.jpg for a two channel amp.
Also look at http://www.hawkaudio.nl

Are you using the same power supply as offered by Hypex?

[Bruno Putzeys]

Originally posted by ninjanki
Why does one of the UCD Monoblocks get consistently hotter than the other? The hotter Monoblock seems to be always warm to the toutch,a nd I can feel this on both the module alum T as well as on the aluminium chassis it is attached. The other module, mounted exactly the same way, some times even feel cold, and I am sure both modules are working...

Any chance you could stick an ammeter in the positive rail (=between the supply and the UcD) and report the idle currents (no loudspeaker attached).

Originally posted by ninjanki
What should be the best sounding capacitor bank I could use? Right now I am using a couple of United Chemicon and Samwa 6800uF capacitors(4x6800 per UCD400), as well as one 100uF eletrolytic, a 470nF polypropilene and a snubber circuit(1ohm + 220nF) per rail.
I am wondering what would be, on your experience, the best main capacitors(Fische Audio, BC 154, BHC, Sikorel, etc...) and what should be the best topology for the other filtering components. I've remember reading somewhere that the extra small capacitors may not work very well with the UCD module, but that is in disagreement with all I've read about PSUs for audio...

The UcD's have local decoupling (the 470uF/100V caps). Adding extra small caps is only done in amplifiers that have no local decoupling e.g. class AB amps.
I prefer to use as few as possible different capacitor types in parallel, because usually the sound is not a mix of the best sonic characteristics of each, but a mix of the worst ones. This is why, if it's not necessary, it's best not to.

[ninjanki]

Bruno, thanks for the reply.

So you do recomend, as a topology, to eliminate the 100uF and 470nF capacitors from the capacitor bank? What about the Snubber circuit, does it also cause more trouble than good?

Thanks,
Allan

[Jan-Peter]

Ninjanki,

Please NO Changes in the snubber!!! This is tweaked on this particuler design and must NOT be changed.

The only thing where you can play is with the 470uF and/or the 22uF on the high voltage rails. And ofcourse the 22uF coupling caps.

Regards,

Jan-Peter

[Bruno Putzeys]

Originally posted by ninjanki
So you do recomend, as a topology, to eliminate the 100uF and 470nF capacitors from the capacitor bank?

The capacitor bank should consist of nothing more than the storage caps. Don't remove any parts from the UcD module (unless you are putting better ones back).

[ninjanki]

Bruno,

About the Amperimeter, I have one, but I am not used to it(use mostly for voltage and resistance measurements...), so I am not sure about how to read given the scale(12A - digital display).

Anyway, it reads 0.05 on the monoblock which seems to remain cold, while it reads 0.07 on the one that is always warm. Is that enough info?

Allan

[ninjanki]

Jan-peter,

I believe I have a Snubber circuit on my capacitor bank too. If there is one on the UCD module, my snubber is useless... I am not thinking, right now, about touching anything on the UCD module... If one day I decide to do so, it will be to replace some caps with Black gates, but not at this point...

Allan