UcD400 Q & A

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My Hypex Mono-blocks (in overkill-style)

UcD 400 HG + Hxr, Sjöström PSU (8 x 10 000uF), Antek 1500VA/2x40V trafo, Jensen JT-11P-1 line-input-trafos.

Arne K
 

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Hi Cobra2,

I think "overkill" is an underestimation in your case :D
Looks cool, man.

In my case, I think a very good PS is not enough:
I have tried some tweaks, like -ECdesigns-'s "charge-transfer supply" to great effect, both in UCD and in my DX HR II amps.
Also worthy is regulation with "PowerReg" from Teddy Pardo, of which I had great experience but with only 30VDC. Soon I will install those in my UCD180 and see if I manage to get 40VDC (uses LM317).

Another of -ECdesigns- ideas is the "stepped rectifier" which will also be tested soon. Much cheaper option.

Congratulations,
M.
 
Guys, a question about grounding.

I have finished my 5 channel UCD400 with 3 SMPS inside. Currently, the 3 SMPS don't share any ground connection (All XLR connectors isolated from the casing) - but it's all driven from a single preamp which does share the ground connections.

Now I want to use a 12V trigger to turn on/off 3 modules which are shared on 3 SMPS - building a circuit with a single transistor (or optocoupler) will mean that the 3 SMPS will be sharing ground that way, possibly creating a ground loop.

What is my best option here? Connect all XLR grounds together, or leave it all as is? Connect all the SMPS grounds together?

Thanks
 
Guys, a question about grounding.

I have finished my 5 channel UCD400 with 3 SMPS inside. Currently, the 3 SMPS don't share any ground connection (All XLR connectors isolated from the casing) - but it's all driven from a single preamp which does share the ground connections.

Now I want to use a 12V trigger to turn on/off 3 modules which are shared on 3 SMPS - building a circuit with a single transistor (or optocoupler) will mean that the 3 SMPS will be sharing ground that way, possibly creating a ground loop.

What is my best option here? Connect all XLR grounds together, or leave it all as is? Connect all the SMPS grounds together?

Thanks

Just curious, what SMPS did you go with?
 
3 times Hypex SMPS400. I couldn't afford 5x mono, and I still had a couple of 400AD's. So I went for a configuration with 1 SMPS powering front left & rear right - 1 SMPS front right & rear left - 1 SMPS center. Front channels are 400HG's HxR - rear channels 400AD's modified for higher voltages.

The trigger circuit I want to build will turn off center and rear modules, effectively turning the amp into a dual mono.

Over dimensioned, especially into 8 ohms speakers. Granite solid amplification for my system.

Thursday I added a W4S DAC-2 (Sabre32 DAC) for music duties - it takes time to open up but now, after a good 20h of running it's starting to feel like I'm in my own audio nirvana. :)

DSC01557.jpg


DSC01560.JPG
 
3 times Hypex SMPS400. I couldn't afford 5x mono, and I still had a couple of 400AD's. So I went for a configuration with 1 SMPS powering front left & rear right - 1 SMPS front right & rear left - 1 SMPS center. Front channels are 400HG's HxR - rear channels 400AD's modified for higher voltages.

The trigger circuit I want to build will turn off center and rear modules, effectively turning the amp into a dual mono.

Over dimensioned, especially into 8 ohms speakers. Granite solid amplification for my system.

Thursday I added a W4S DAC-2 (Sabre32 DAC) for music duties - it takes time to open up but now, after a good 20h of running it's starting to feel like I'm in my own audio nirvana. :)


Very impressive. How do you like the performance of the Hypex SMPS compared to their linear power supplies? I haven't read much discussion of their SMPS regarding sound quality. Hypex hasn't said much to praise them, but that's also true of their other products. They sure aren't prone to hyperbole.
 
The SMPS are impressive. I can't possibly get near max power on these modules, but at testing I was running one SMPS with two modules - turning up volume and never heard any form of compression (=telltale PS can't keep up) - idling, the modules are silent just like with a linear PS. Sound to me is as perfect as it comes. With the DAC-2 now, the UCD's+SMPS just sing. If I went overkill, it's because I can - plenty power :)

PS. Google on IANMAC ATC UCD400 - you'll find a thread with a very happy SMPS+UCD user.
 
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Hi Jan-Peter

I have got a question about over current protection of UCD400 :D

In datasheet UCD400 from Hypex,over current protection is 18A peak,I see UCD400 use resistor R = 0.05R/2512 in place from B+ to Drain of power mosfet (FDP42AN150/TO220),if I=18A,R=0.05ohm => P(on R) = 18x18x0.05 = 16.2W peak # 11.45W rms, resistor size 2512 not enough power 11.45W,I want to question this resistor can really safe? if I always use at near level 18/1.4142 = 12.7A example about 12A(# 24Vrms signal ouput) with 2 ohm load resistor(not speaker) at output and input is sinwave 50-60hz?

Thank you very much
 
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I have a multichannel setup with 5 UCD amp modules (3 x UcD400AD and 2 x UcD180AD). One of my UcD400AD modules has crapped out and I am trying to find a replacement. Unfortunately it is way past warranty and is no longer available for sale. The amp was built in 2005.

If any of you have upgraded to a newer UcD module, like the UcD400ST or UcD400HG (or even jumped to the new nCore modules), and have a spare UcD400AD module, would you be willing to sell it?

Otherwise, what current UcD400 module is the best match for replacing my UcD400AD?

Thanks!
 
I have a multichannel setup with 5 UCD amp modules (3 x UcD400AD and 2 x UcD180AD). One of my UcD400AD modules has crapped out and I am trying to find a replacement. Unfortunately it is way past warranty and is no longer available for sale. The amp was built in 2005.

If any of you have upgraded to a newer UcD module, like the UcD400ST or UcD400HG (or even jumped to the new nCore modules), and have a spare UcD400AD module, would you be willing to sell it?

Otherwise, what current UcD400 module is the best match for replacing my UcD400AD?

Thanks!
Hi Greg
I have one spare UCD400AD module which I can offer you at cost, it has better caps than original and works flawlessly (I kept the 8620 intact).
My email address is yair at audioclinic dot co dot il.
Cheers
Yair