You're definitely welcome. The Max will probably be a bit of a challenge for you, I know the first one I built wasn't without its fair share of problems. My advice would be to try and break the web sites down into sections, and try to digest them a piece at a time before moving on to the next. Also, have a good plan in place before you start building to avoid any issues that might pop up during the build process. It might look something like this:
1. Determine your build's bill of materials. I'll run you through the optional/commented sections to the best of my knowledge.
a. Decide on boutique caps (Vit Q's from Beezar, Elna Silmic II's from Handmade, etc.)
For example, on my build, I chose to use .22uF Vitamin Q caps from Beezar for my CA8L/R positions, and 1000uF Elna Silmic II's for CA2L/R and CA7L/R. The other film caps are all Wima's like on the standard BoM.
b. Buy and match the 2N5087 and 5088 small transistors. As the comment in the BoM states, you'll want to buy at least 50 of them, and a cheap meter from Harbor Freight that lets you measure the HFE of the transistors to match them closely. This is documented on the Max site as well.
c. R1 10ohm 1W heater resistor. Install this one, don't consider it to be optional.
d. Choose what color LEDs you want to use - Beezar.com has several to choose from.
e. If you want to use an on-board fuse, you'll need to plan accordingly and order the fuse clips and a 5x20mm 1A slo-blo fuse. Install a 3 position terminal block for the power so you can wire it to either use the fuse or bypass it if you wish.
Everything else is basically just an alternate part number, except for the heatsinks. Just get the 1.5" heatsinks otherwise you will have to run the MOSFETs at reduced current levels, which is not ideal. Stick to Mouser for most of your parts, get what you can from Beezar.com, and you might have to order your larger boutique caps from elsewhere if you wish to use them. I'd go ahead and get 5 of the heatsink mounting kits from Beezar for the VREG and your MOSFETs while you're at it. It won't hurt to order one or two extras of all your parts, especially the less expensive ones, in case one gets damaged for some reason or another.
2. Organize your parts as they come in. A HUGE benefit is to use the "custom part number" feature of Mouser's cart so that as you add an item to your cart, you can verify that it is what the BoM calls for, and then name it for the Part ID that it has on the BoM (So you'd type in "RA1L/R" for the 5K Ohm Trim Pot).
3. Plan ahead, and think about how the build will go. Arrange your parts by height, so you won't miss a small part that has be snuck in between some taller parts. If you want to go ahead and do the case work beforehand, go for it, or you can wait until you know you have a working amp.
4. If you want to remove the pin that holds the tube sockets together so the LEDs can shine into the tubes better, do that and use some epoxy to glue them back together the day before you plan to start building the board.
5. Populate the board, and check to make sure the proper parts are going in the proper places as you go. Again, the silkscreen on the board tells you the name of every part on the board, and how it should be positioned. You just have to make sure it's the right part. The more thorough you are, the more likely you are to have you board fire right up when you turn it on, and not catch on fire
6. Check everything again after you're done. Make sure you don't have any empty places on the board, make sure you don't have any parts installed backwards (other than the QB2/3 transistors, which is explained on the Max site). Check for any solder bridges or leads you missed. Clean up the bottom of the board to remove excess flux. Make sure your DB trimmers are turned all the way down before you fire it up.
7. Temporarily wire up your power and turn it on. Observe for signs of smoke
. Immediately check your DB voltage to make sure you aren't running too much through the buffers (in case you didn't get the trimmers turned down properly). If your DB voltage is nice and low (or 0) then go ahead and set your power supply voltage to 27VDC, then set your left and right tube bias to 13.5VDC each, then get to work on your DB voltage till you get it to around 175mv/80ma. Check to make sure nothing's getting overly hot. The heat sinks will get rather warm, but make sure no other parts are too hot or anything.
8. Turn off the amp. Put it in the case, hook everything up, start listening, and gradually raise the bias for the DB up to 275mv/125ma.
Again, all of this is outlined pretty well on the Max website and some of it is just from personal experience. I'm sure others more knowledgeable than I am can chime in with their own advice
