Hey Everyone, I built a wicked sounding Harvard recently and am very, very happy with it. I made a couple small changes to the circuit, including using a ClassicTone choke. I'm using a very warm speaker with the amp (too warm!) so I added in a small bright cap across the volume pot, which will stay there and get removed if ever I put in a better speaker match for the amp (like the 1028k). In short though, I'm very happy with the sound of this one and it's every bit as gorgeous sounding as the Champ, Deluxe and Bassmans I've built in the past, but with it's own special, Harvard character. I've noticed more guitar noise through this amp that I'm used to. It's very quiet with PAFs, louder with my Tele, and loudest with my Strat. It's not a typical single-coil hum though, it sounds like some kind of EMF noise is getting into the amp via my guitars or my cable. When I turn the guitar volume down, the noise disappears completely, so it's definitely guitar-related. However, I made the dumb decision to leave out the 1M grid resistor on the input jacks, as per the 5F10 schematic, knowing fully well that it's better to add one in, just to see how the stock input wiring behaves. I'm inclined to add it in regardless, because it's better design, but wanted to ask one question: Can leaving out this resistor induce guitar noise into the circuit? Is there some kind of noise filtering related to the 1M resistor that's not happening when it's absent? Thanks so much.