I usually listen to tunes using my Samsung Note 3 phablet and the Android app PowerPro, and have recently bought myself some Bose QC15's as there are times when I need the ANC. Please don't bash the Bose as I bought them cause they were the only decent headphones with ANC I was able to try out in the store before buying-now that headphones are not returnable after opening the package.
I know a lot of audiophiles buy headphone amps so I am wanting to know the pros and cons of them. Also what is the primary reason most people buy them? Is it just to boost the volume due to the device they are using ie; ipod, phone, tablet etc.? Do any of the headphone amps come with a built in equalizer? There are times when the built in equalizer for the PowerPro app is inadequate and I'd like to boost either bass or treble, etc.