[Olop]

From the part list for "Integrated Circuits" on the website, there are 2 U4 and 2 U5. Does it means that we choose either 1? Is it alright if I choose "high performance" edition for both U4 and U5? 
 

 
Another question is there are knob and volume/power switch. Are they referring to the same part? As I don't quite understand that part. 
 

 
 
Lastly, I found online that it is better to set to Gain of 2. Is it really so? Can somebody help me with these questions? Thanks a lot in advance!
 

 

[bcg27]

Its pretty clear on the website - one part is for the high performance version and one is for the extended run version. Pick which version you want to build and go with that item from the parts list. You probably do not want to mix one part from each.
 
The pot with a switch actually controls the power and volume. It most likely has something like a 3mm shaft which the knob will screw onto so it is easier to grab and turn. They are seperate parts, and I guess the knob isn't strictly required but I wouldn't recommend building it without one.
 
As far as gain it really depends on what your source is and what your headphones are. I would set your gain as low as it can be while still maintaining the ability to get all of your headphones as loud as you want. If you are using IEMs with it then a gain of 2 is probably good. If you plan to use less sensitive full sized headphones you may want something a little higher like 5.

 

[Olop]

Quote:

Its pretty clear on the website - one part is for the high performance version and one is for the extended run version. Pick which version you want to build and go with that item from the parts list. You probably do not want to mix one part from each.
 
The pot with a switch actually controls the power and volume. It most likely has something like a 3mm shaft which the knob will screw onto so it is easier to grab and turn. They are seperate parts, and I guess the knob isn't strictly required but I wouldn't recommend building it without one.
 
As far as gain it really depends on what your source is and what your headphones are. I would set your gain as low as it can be while still maintaining the ability to get all of your headphones as loud as you want. If you are using IEMs with it then a gain of 2 is probably good. If you plan to use less sensitive full sized headphones you may want something a little higher like 5.

 
Oic...thanks a lot for those info!