Crikey! No domestic plug. Dimmer is outputting, yes. Socket and plug are good. £40 for a wiring set. Eesh. Thanks for the suggestion. I have a couple of dozen second hand fittings of which most are GY9.5 and finding I quite often need to replace lampholders, particularly after a bulb failure. Most are cheap, basic and not very effective [Microspot 308/Minim23 calibre] this is rapidly becoming a cost effective decision as a new lampholder costs more than a cheap LED flood which is in many ways just as acceptable for a back street AmDram and certainly easier to rig/focus for many of them. I'm not trying to put a source4 into this category, just commenting on the lampholder failures. Hahaha! 'I'm nor saying they're a problem... but I'm directly associating them with other heads which are a problem!" - something like that? :-) No love lost, you could well be on to something. Solid advice. Will try this first.