UcD400 Q & A

[Sidiropa]

having replaced the buffer opamps from 5234 to LM4562 and prepared the module to accept an external buffer supply, would I be able to supply 15v or would I have to stick to 12V? The LM4562 definitely can, but are there any other parts that would object?

[Junpu]

Can someone send me a copy of UcD400 datasheet R10 version? I have only R9 on hand, but I need R10 for my UcD400 sample evaluation.
Thanks

[Yves Smolders]

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

[greggp]

Originally Posted by Yves Smolders

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?

[Yves Smolders]

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.

[greggp]

Originally Posted by Yves Smolders

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.

[Yves Smolders]

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.