Its heavy and a peek behind the back board looks like some seriously big tubes, but interestingly very little in the way of ventilation.
The big control in the middle is a 3 position switch labelled 200/400, 300/600, 1000/2000
Its made by Phillips - and both ends are the same, each with a big knob and a small knob.
One big knob changes the dial setting labelled 'S' and the other the dial labelled 'P'
Its very very odd.
Any help identifying this would be much appreciated.