[doggie]

Hi,

I am pulling together the last few parts for my UCD180-AD amp. The final choice is the chassis. The rest of my DIY system uses some nice aluminum boxes from Par-Metal so I would like to match them. They are small in size being 12 x 8 x 3 inches. I have figured out the layout and it will work but am a little concerned about radiated fields within the chassis from the AC, trannie, and class D modules being close together.

My question: Is it worthwhile using a couple of aluminum dividers to separate out the different sections or would this be a waste/unnecessary?

Thanks,

Paul

[Kevin Haskins]

Hi,

I am pulling together the last few parts for my UCD180-AD amp. The final choice is the chassis. The rest of my DIY system uses some nice aluminum boxes from Par-Metal so I would like to match them. They are small in size being 12 x 8 x 3 inches. I have figured out the layout and it will work but am a little concerned about radiated fields within the chassis from the AC, trannie, and class D modules being close together.

My question: Is it worthwhile using a couple of aluminum dividers to separate out the different sections or would this be a waste/unnecessary?

Thanks,

Paul

The aluminum is a good RF shield but a poor EMI shield.   Inside the chassis you primary concern would be EMI so I'd say you will gain little with aluminum partitions.   Good layout and construction technique will go far and the UCDs are not terribly sensitive to EMI/RFI problems within the chassis.   If you where using a SMPS I might be more concerned but you should be fine without it.

I prefer a steel chassis because it is a good shield for both EMI & RFI.   The transformers we are sourcing also have an extra gauss shield to limit the already low EMI field of the power transformer.   Overall as I said, use good layout, proper wiring and good grounding and you won't have any audible problems.

[eLarson]

would copper-plated steel work?   Steel for the magnetic field, copper for the e-field?

I saw something like it, if memory serves, in a Marantz product.  It looked cool, if nothing else...

[Kevin Haskins]

would copper-plated steel work?   Steel for the magnetic field, copper for the e-field?

I saw something like it, if memory serves, in a Marantz product.  It looked cool, if nothing else...

Sure it will work.   Will you hear a difference?   I seriously doubt it.  

Here is how we lay out our chassis.  The aluminum heatsink might offer some shielding but once again, I doubt if it makes an audible difference.   If I were going to partition a portion of the cabinet I'd do the transformer/softstart.  

On ours we carefully twist the power supply lines and use ties to hold them away from the shielded low level signals.   Position the modules to keep signal & output wires short and close to the rear panel.   Keep AC lines some distance from all signal level areas.   Distance works wonders for EMI.   RFI is more of a concern from outside the chassis so following the balanced wiring connections suggested by Hypex will help the chassis to provide good shielding.  

[doggie]

Thanks for the tips Kevin...