Hi all, new here~.
I’d like to ask if I already have a Hi grade DAP like Fiio M15, is it still make sense to purchase a desktop AMP/DAC (For example, MAGNIUS & MODIUS) even the DAC chip is not as high end as M15?
Assuming I’m using a headphones that not very hard to drive. (<150ohm)
thx
welcome to HFG!
if you can connect it to your PC / Notebook via USB to stream music through it, then yes, you can use it as a DAC / Amp combo.
as you noted, you’ll be limited to easy to drive headphones 
Welcome to HFGF 
yes they sure can but you’ll get a lot better bang for your buck with a desktop solution, depending on what you are driving headphone wise something like a BF2 and Rupert Neve RNHP will be a whole lot cheaper than say an R2R Dap like the L&P P6 Pro which sells for $3,899. It just depends on if it really needs to be used otg.
For my case, DAP is a must, because i need it to be portable, so the question is should I looking for another set of desktop amp/dac?.
Base on u and Marzipan’s response, it seems like I dont need to.
hmm… maybe i can just buy the amp when i need more power.
honestly if that’s the case, another option would be buying both. You don’t need to get something super high end for otg and you can buy another nice desktop solution. So instead of a 1k dap you could get a 200 dollar OTG dap or portable amp plus a desktop solution that costs 800 total or so. etc.
It really depends on your headphones. I have a Sony NW-ZX300 and it sounds great driving Grado’s, Meze 99 Classic’s and my newest toy, the CFA Cascades.
It does not do great with Focal Elex’s, HiFiman Sundara’s and HD660’s. It will work with these, but…
Really comes down to your choice of headphones.
well yes and no. If your planning on expanding your collection of headphones then you definitely should. But if you happy running wtv your running now. Just keep it that way
@Lester As an M15 owner, I would say that it likely could replace a desktop setup. The over ear + high gain mode drives everything I’ve thrown at it including 300ohm Sennheisers and the entire ZMF line. For my needs, or for anyone looking to drive full sized headphones portably, I think it’s the best Android based DAP available. I suspect you get better performance from a non-streaming capable DAP like the Sony offerings, but I’d have to sacrifice streaming and give up the idea of headphones.
That said, if I listened mainly to iems, and wasn’t on the go for most of my listening time, the M15 is a bit of overkill. As Jose and others above have mentioned, you could easily go with a HIBY or other mid-range DAP and still have plenty of money left over for a desktop setup with the same budget. I haven’t used the M15 in DAC only mode, but the DAC/amp combo they are using is really nice to my ears. It should do a decent enough job as a desktop DAC, but I’d worry about having it plugged in and running all the time vs. my current use cases. I would expect a lot more longevity out of a standard desktop option that’s meant to be left plugged in and running.