Since most (all?) laptops have a power block, the ground on that third prong ends there. Once it hit's the transformer, it's not doing anything. Waitrob has it right. That third prong is to help avoid a shock of something goes wrong. So short answer, it's fine to run the laptop that way. If you have an extra of the cord that goes between the power block and the wall, just break off that third prong. I did this to the power source for my Starving Student to try and get rid of hum, but it had no effect
Well I finished building my amp tonight, sorta. Other then the part I missed in my order
Funny part is, it was mentioned that P1L and P1R were missing from the BOM. It got added, but it is listed incorrectly as P2R and P2L. There are 2 items for those locations. When I was building my BOM I think I deleted the 200ohm trim pot thinking it was something that had been changed. I didn't notice there was no P1R or P1L.
Oh well, I was really hoping to listen to it this weekend, but I'm too cheap to pay for 2 day shipping for $5 in parts lol I guess it will be sometime midweek before I get to hear it. I already placed an order with Digi-Key for the trim pots. Naturally I was able to find other things to order.
FYI, if anyone is thinking about socketing Q1-8, it's a major PITA! The sockets for Q6 and Q7 aren't too bad, but I used the same DIP sockets as the test points for all the TO-92 transistors. So 6 per channel, 3 pins each. That's 36 tiny little sockets to solder
Also I discovered my tube sockets don't have a hole through the center for the LEDs
There are some silver circles where the holes should be. I poked at them hoping it was just some thin foil-like cover, but no luck. I might take a drill to them if I decide I have to have the LEDs under the tubes. Otherwise, I might just use the 3 LEDs to light up the inside of the enclosure and have it shine through the ventilation holes.