Instruction: Assess the user's sentiment in the provided review and select the appropriate sentiment option from the list as the answer.

Input:
I'm listening with my new HD600 + Apogee Duet headphone amp, and it's amazing. If you try using these nice cans to directly plug into your macbook pro or ipod, you're really wasting your money. I also have Etymotic ER-4P's and they sound nearly identical without microphone amp. With an amp, it really sets it apart, especially if you're going to pay almost $400.

Options:
A: very positive
B: positive
C: neutral
D: negative
E: very negative
Answer: A: very positive