Help recommendation DAC / AMP for headphones (Combo or separated units?)

[Infinit0]

Hi everyone. Love this forum.

I have a pair of Sennheiser HD599SE (50 ohm) and AKG K371 (32 ohm). I use them for listening music (all kind of genres) using FLAC or TIDAL mostly.
I do not have plans to change the headphones until a few years to come, this is important because both of them are low impedance headphones.

I'm looking for improve my listening experience and pleasure with some DAC / AMP to replace the onboard sound on my computer, also I usually play the piano (digital one) through a VST using ASIO drivers.

So, what should I buy?

Keep it simple (Combo):
1. Ifi Zen Dac V2 (I like that doesn't have a dedicated power supply)
2. Fiio K5 Pro (Good option maybe too much power that I not need?)
3. Topping DX3 Pro (Idem Fiio, also expensive)

Get separated units (Cons: I need to connect 2 devices, is really noticeable the quality compared to the first 3 options?)

DAC:
1. Topping D10s
2. Schiit Modi 3+
3. JDS Labs Atom DAC

Headphone AMP:
1. JDS Labs Atom AMP
2. Schiit Magni 3+

For reference I have owned (not anymore):
Sennheiser HD598CS, Sennheiser HD650, Audio Technica MSR7b, Sony MDR 7506
E-mu 0404 USB, Audioquest DragonFly Red, Fiio E10K

Thank you everyone!!

 

[Infinit0]

OK one thing I didn't mention. I live in Europe. So the prices of almost all devices are kind of high.

1. Ifi Zen Dac V2 $159
2. Fiio K5 Pro $199
3. Topping DX3 Pro (Discontinued so, discarded, also very expensive)

DAC:
1. Topping D10s $99
2. Schiit Modi 3+ $135
3. JDS Labs Atom DAC (Not sold here)

Headphone AMP:
1. JDS Labs Atom AMP $157
2. Schiit Magni 3+ $135

That let me with such a few options, a Schiit combo will be $270 and a Topping + Atom $256, when a Fiio K5 Pro is $199 and Zen Dac v2 $159. Having this prices, the best bang for the buck is the Ifi Zen Dac?

 

[AnalogSteph]

Potential amp option number 3, Topping L30, should be in the same ballpark price-wise.
I would also consider the Magni Heresy in addition to the 3+, but the Schiit-Europe shop is still showing "Availability: new stock date not clear yet" for both, so who knows when they'll come back in.
I might also consider a classic Objective2 from Head'n'Hifi (either desktop or standard version, 150/120€ respectively). Not as powerful as an Atom or L30 but also very low noise and, being a DIY design, very service-friendly (you can also get a kit for 70€ + 20€ for desktop version parts if the soldering iron is your friend).

What kind of onboard audio do you have? If that is half-decent (read: the rear output is clean), getting a good stereo 3.5 mm to RCA cable for use with one of the above amps would be the bang/buck option for sure. Realistically, every common Realtek chip from the last decade is good enough as a pure line-level source if the implementation isn't screwed up (which I'll admit may be board manufacturers' favorite hobby). Even if a 95-98 dB(A) dynamic range isn't wowing anyone these days, with a volume control following it still is plenty adequate. (Sometimes you have to be careful not to use master volumes past about 70-80% if the board manufacturer thought a mere 3.3 V supply for the analog stage adequate.)

Zen DAC V2 also looks quite attractive, but in V1 the headphone driver wasn't all that hot in the noise and distortion departments and the DAC, while potentially a big step up from onboard in dynamic range and voltage, didn't fare so well in the distortion department either. It looks like V2 may mostly have upgraded its XMOS chip from 208 to 216, with more DSP power to go along with it, as well as upgraded the oscillator (not like you typically need that). Unless you absolutely need MQA or 384 kHz output (which, realistically speaking, nobody really does, at least for audio), I'd rather be going with an O2 and the trusty onboard audio.

 

[Bob-23]

I might also consider a classic Objective2 from Head'n'Hifi (either desktop or standard version, 150/120€ respectively). Not as powerful as an Atom or L30 but also very low noise and, being a DIY design, very service-friendly (you can also get a kit for 70€ + 20€ for desktop version parts if the soldering iron is your friend).

Fully agree, it's a good amp, rock-solid metal case, easily repairable through-hole technology (hand-soldered). Opamps are socketed. I have several of them in use - if longevity is a criterion for you: that's the choice.
(SINAD in other amps might be lower, but what's the point if you don't here it anyways. O2's noise and destortion figures are suffcient!)

O2 Design Process
http://nwavguy.blogspot.com/2011/07/o2-design-process.html

NwAvGuy: The Audio Genius Who Vanished
An anonymous engineer created some of the best DIY audio designs—and his fans want to know where he went
https://spectrum.ieee.org/tech-history/silicon-revolution/nwavguy-the-audio-genius-who-vanished