Class D Audio amp noisy when bridged to mono

I have two Class D Audio amps set up as a three channel for HT use, and two amp modules sharing a common power supply bridged to mono for my stereo pair. The modules and power supplies are designated as the CDA 254.

In the three channel amp, only the bridged module is noisy, the module used for the surrounds is quieter. The amp for my mains, using the two bridged modules, is noisy. I am in hopes someone may have a cause for this noise, and hopefully, a cure for it. I do wonder if the noise is due to the shared chassis and power supplies? This noise, to me, sounds like a switching noise, and is seemingly double the same noise being emitted by the module in stereo mode.

I contacted Tom at Class D several weeks ago, he hasn't replied yet. Thanks for any help or ideas that you good folks can come up with.

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Funny how none of the class D amp fans that are quick to praise the design on this forum haven't posted in this thread to help a brother out.

I've heard amps from this brand when I bought a pair of speakers off a fellow audiophile, and they impressed me.  But he did have top of the line PS Audio power cables and high end speaker cables as well.

As for your problem, it sounds to me like you really need the input of the manufacturer, I'd contact them again every day until they make time for you.  It sounds like you've purchased a few of their products, surely they support their customers.
Yeah, 213runnin, there hasn't been any help forthcoming. You're probably right, I've got to get Toms's attention somehow. In the meantime, the music still sounds great.

Out of curiosity, what does "switching noise" sound like? Its one of the more popular criticisms of the class D amps in general and I've never heard anyone try to describe it in subjective terms.