Picked up a NR head version on the Emporium. Once I got it fired up, I noticed the pilot light was out and there was a good deal more hum than it should have. The hum was attenuated somewhat when the Mid control was turned down. A new bulb wouldn't light, so I was thinking "shorted lamp." Sure enough, disconnecting one connection to the lamp got rid of the hum. Now, even turned up, it is very quiet. Only had a little playing time on it but, so far I love the sound & response of this; my first BF-style amp. Also, the first pro-built amp I've bought in over 20 years. This one's loaded with 6L6s. Will try a pair of np Tung Sol 6V6s eventually.