I asked and some guy told me Lake People is not that good and not that neutral, and that I must spend $500+ if I want a neutral amp:
So what should I do? I need a neutral sound for mixing, I don't want warm or too much trebble approach.
nope not for proper neutral, the rest is basically neutral'ish with a warm tilt or warm. It cost money to get neutral especially if you want it to be detailed/revealing, since then you start to get into the pro gear realm. You must also take into consideration that a lot of people tend to enjoy a sound that is a bit warm. Though I don't fully understand why this is so important for you, since your headphones are already very colored in their sound and a neutral amp won't change this.
Lake people isn't that good anymore, their amps tend to focus more on bass reproduction than mids and highs, so the bass stands out more. The reason why I don't have any lake people gear on my list is because their value isn't that amazing anymore, unless you need multiple headphone outputs and the performance value has dropped quite a bit over the last 5'ish years. A lot of their gear also seems focused on this middle ground between entry level and high end, which in audio is a pretty bad spot to be in, since the smart thing to do with audio gear is to run entry level until you can make the jump to high end, that is at least the way to go to spend less money. The jump from your typical mid range unit to a high end unit is often fairly big, while the jump from a good entry level unit to mid range unit is often not as big.
I wouldn't buy the G103-P new, but you can always look used and then the value should be decent/good. Nothing wrong with buying used and it is from 2012, so there must be some up on the used market somewhere.
So what should I do? I need a neutral sound for mixing, I don't want warm or too much trebble approach.