well good luck. half power switch is a good idea, and reebmmer that this will change the expected speaker load to 8 ohms (rather than 4). I just got a new quad of 6L6s for mine, v v v curious to see how much this improves the sound. 6L6s have gotten expenseive! Rubys were the cheapest i could find, $60 for a quad. Just two years ago i was getting russian 5881s for $9/each .