[mario_34]

I'm looking for a portable amp/dac that will bring out bass in some cans.
I have right now the nhr-21 (IEM) that handle bass great with my iphone as the source but also have ATH-M50's as my over ears for right now until I get some better hard hitting over ears.

The source will be my iPhone.

 

[serman005]

Check out the FiiO Q1 and see what you think. There is a bass boost feature that might interest you.

 

[Old Dirty Puppy]

I use an Oppo HA-2se as my portable DAC/amp. It has a great bass boost that is subtle and not to overpowering. It also has a low and high gain switch to power full size headphones or IEMs. The Oppo HA-2 is a great pair with iPhone and it comes with a usb lightning connection cable. I wish that it came with a usb type C cable so I could use it with my Galaxy S8 without an adapter. I love this DAC/amp, I use it as my portable daily driver for my audeze iSine 10. On a few rare occasions I have even used it to power my pair of LCD-2 and it worked great.