1) If you use a dap, is there a hiss?
That depends on the quality of the DAP's circuit, and sometimes the software, and whether that circuit has any issues with the low impedance, high sensitivity load of certain IEMs. You'll have to check each DAP's thread and confirm if the IEM you want to use with it hisses or not.
or Would I need to use an amp to get rid of it?
Same thing about the hardware here. Some amps still hiss with the SE53x for example.
Like when I use andromeda on my v30, there is a noticeable hiss, but when I plug in my portable amp, the hiss goes away.
That's because the headphone output now sees an easier load. Very high impedance but since it isn't a complex load like a moving transducer, there are a lot less impediments to how it can send the signal. It's basically working as a line out, with the exception that there's a headphone driver circuit inside the chip.
That said, are you sure it isn't software? Most IEMs and smartphones have a noticeable hiss when plugged in, same thing with my Galaxy S and Note phones, and even through USB digital output. Open a player app and the noise goes away even with the volume on the phone (with IEMs plugged in) or the amp (if using OTG) cranked up.
2) I use a v30 but I was wondering if I were to get a dedicated dap, what would be on the same level or better than v30?
If in terms of output power, probably something like the Fiio X3 or X5. If you want even more power there's the X7 and some modules. No guarantee that any of these DAPs or X7 modules won't have the noise though unless somebody who uses the same DAP and IEM can confirm that the combination doesn't.
You can try an impedance adapter first. Even a good quality one that doesn't come as a bulky pigtail cable wouldn't cost that much more. If it eliminates the noise on the V30 then you can use it there and maybe not get the DAP; otherwise, buy the DAP, and if there's noise, try the impedance adapter there before trying another DAP.
