UcD400 dual Mono Build: done right?

[fred sonnen]

I have build a dual mono UcD400 as my LF amplifier. This is my first amplifier build. So would like to ask you if id everythink right....

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I connect the main and the HxR led's were on and I saw and smell no smoke ;-)

Thanks for your feedback

regards
F.S.

 

[Windforce85]

Congrats on right amplifirer choice. Properly assembled it will beat 4x more expensive amplifiers in every aspect.

I have a bunch of advises:

- get rid of mains input filter. SMPS really likes direct connection to the mains
- shorten AC mains wires inside the chassis, twist them tightly in pairs
- twist input signal cables tight in pairs
- use shielded XLR cable inside the chassis. Connect shield to the GND and chassis. Stick to the rules outlined on page 14 of NC400 datasheet:
http://www.hypex.nl/docs/NC400_datasheet.pdf
- consider switching to the XLR connection. Pin 1 of XLR then goes to the chassis.
- you should use 3x plastic spacers below SMPS modules. There is only one metal spacer needed - it is outlined on the PCB.

 

[fred sonnen]

Thanks for your feedback!

...
- get rid of mains input filter. SMPS really likes direct connection to the mains

Do you think the Fuse is a filter?

- shorten AC mains wires inside the chassis, twist them tightly in pairs

I am not sure if I will shorten the org. Hypex cable... How do I reconnect them?

- twist input signal cables tight in pairs
- use shielded XLR cable inside the chassis. Connect shield to the GND and chassis. Stick to the rules outlined on page 14 of NC400 datasheet:
http://www.hypex.nl/docs/NC400_datasheet.pdf

I have no idea how to handle the earthing....
my understanding is that UcD and NC400 is are a little different regards earthing (?)
The audio in is a org. Hypex cable. Acording to the manual you can use these for RCA and XLR connectors.

- consider switching to the XLR connection. Pin 1 of XLR then goes to the chassis.

All my interconnections are RCA...

- you should use 3x plastic spacers below SMPS modules. There is only one metal spacer needed - it is outlined on the PCB.

Is this nice to have or is there a specific reason for that?

 

[Antana]

Hi Fred,
The mains input filter should not be removed, this prevents EMI into the net and visa-versa.
XLR is a balanced interconnection and is less sensitive to interference. You can use an unbalanced connection like RCA. To do that correctly, take a look at this app-note..
About the spacers: In chapter 2 of the datasheet you see the red marked primary part of the power supply. If you use metal spacers in the three holes, you violate the Class 2 safety. Therefor, try to find three plastic spacers as Windforce suggested. Its for your own safety.

 

[fred sonnen]

Did the plastic spacer and reconfigure the ground. Now the UcD400 is up and running 😀
I am quite happy with the results. The amplifier is just responsible for the LF. MF and HF are made by two croft serie7+ hybrid amplifiers.
Thanks for your advice!
Regards
F.s.

 

[Windforce85]

Thanks for your feedback!


Do you think the Fuse is a filter?


I am not sure if I will shorten the org. Hypex cable... How do I reconnect them?


I have no idea how to handle the earthing....
my understanding is that UcD and NC400 is are a little different regards earthing (?)
The audio in is a org. Hypex cable. Acording to the manual you can use these for RCA and XLR connectors.


All my interconnections are RCA...


Is this nice to have or is there a specific reason for that?

SMPS400 has complete safety stuff onboard: mains filtering and the fuse. No need to connect anything than mains. Oryginal Hypex cables for SMPS aren't the best of the world. You can disassemble JST connectors from stock wires and make your own cables with best suitable length. UcD and NCore will share the same earthing shedule. Bruno is very consistent in his electronic designs. XLR connection scheme has a huge benefit of provide you differential signal connection which is completely shielded and noise-proof. But you can use RCA completely fine, though.