Dimming LV transformers

["John B" <home-automation@xxxxxxxxxxxxxxxx>]

Hi all,

I've just installed a new light fitting for SWMBO - the old one was just
a regular mains fitting, whereas the new one has an integrated LV
transformer.

The light is wired to a C-Bus dimmer channel, and whenever it's switched
on, the transformer buzzes quite loudly.
Doesn't seem to matter what brightness the light is set to - the
loudness of the buzz remains the same - it only disappears when you turn
the channel off completely.

If I connect the light to a C-Bus relay, there is no buzz from the
fitting at all, so it's definitely down to the dimming.

What are my options here? I really need to have diming control, as this
is a hall light which comes on at low levels during the night.

The transformer has no markings on it (so far as I can tell) to indicate
whether it's suitable for dimming.

Is it just a case of replacing the transformer with a higher quality
one?
There is no access to the ceiling void above, so any replacement
transformer will need to fit in the top of the fitting where the current
transformer is mounted.

Thanks in advance for any advice.

Regards,

John