Chameleon 1000D, 2000D, and 4000D amplifiers

These MHA (Malcolm Hill Associates) Chameleon amplifiers are almost 15 years old but they still look virtually like new and still work well.  Even by today's standards, they have very healthy power ratings, especially in a 1U package.  (The four amplifiers together will deliver a total of 7400watts into 4ohm loads, all in 4U!)  The Chameleon "D" range was the immediate predecessor to the "D2" range (which repackaged things into 2U cases with silver front panels but which are virtually identical electrically).  The Chameleons were known for having teething problems but these units are way beyond that stage and have since proved to be completely reliable.  Hopefully they have a good few years left in them yet!

Each amplifier is 1U high, but they vary in depth.  They have conventional ("linear") power supplies with large torroidal transformers (huge in the case of the 4000D!).  They are fan-cooled using two quite sophisticated radial blowers and wind tunnels (one in the case of the 1000D).  The fans are controlled by both temperature and signal (so operate when the amp warms up, or instantaneously with a large input signal).   Rather than use gain pots for level control, the Chameleons have button-operated precision stepped attenuators that may be set to 0dB, -2, -4, -6, -10, -20, -35, -55, or -infinity dB, thus allowing completely reproducible gain settings.  Note that the 1000D and 4000D are not rated for operation into 2ohm loads (or 4ohm when bridged).

When new, list prices (ex VAT) were £785 for the 1000D, £1395 for the 2000D, and £1995 for the 4000D.

The original manuals are not available.

Press quotes from trade mags (according to MHA literature at the time):