Went there yesterday. Got my JCM900 (4100) serviced - it had blown both output valve stage fuses but it turned out to be just a short in a valve and not the amp's circuitry. Also had a tour of the factory - third time I've had a look round now. The factory workers are actually on Easter break so not much going on. It did mean that we got to look at a couple of bits you can't normally see & you could talk at a reasonable level without the machinery noise. The guys there are always great, very helpful and very knowledgeable. Where better to get your amp serviced than the place they built it!