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I've built some acoustic guitars and I want to get into some electric builds. On that note, I have a highly regarded player around here asking if I could wire an existing solid body to his liking. He is providing two 500K pots, two P90 pickups and a 3 position switch. He wants two volume controls, no tone control. He's quite an accomplished player and I don't know enough to question him. I got a Seymour Duncan diagram from their site and it seems simple enough but most P90 diagrams I see use 250K pots, one used 300k but none using 500k. Seymour Duncan shows no resistors , are any necessary? If your using the switch in the 'both' position how does that effect the two volume control set up? I assume you still retain control of each pickup individually and set your volume for each? Thanks for any help with this