Just for using my wired headphones via phone / on the go with other devices reliably with a transparent sound and good amplification, no need for Bluetooth. I’m an audio engineer but I’m not looking for tube mojo or similar unnecessary audiophile requirements, just a clean sound.
I was looking at the Moondrop Dawn Pro, is that a good idea?
The Apple dongle dac (usb-c) is good to have if you want something to live on your iems.
I have limited experience with the Dawn Pro. In terms of power it should be a step up from the dongle dac, or if you need balanced outputs.
Gizaudio on Youtube reviews a bunch of chifi dongle dacs around your price range. You can check them out for other options as well.
I use the iFI Go-Link, roughly in your price range. Not much below that level with any power, the Apple dongles sound good but are lower power.
Yep, looks super clean, about as much power as you can ask for your HD650 from dongles in that price class - I haven’t seen anything that can surpass 4 Vrms for $50 and stay as clean as Moondrop advertises for the Dawn Pro. Seems like a prime candidate on pure sonics. Just try to keep its volume always at least one step below max - if it’s anything like its older sibling when dealing with busy material its total distortion might jump by a lot at that final volume step.
The part that’s not so great is its build, with some percentage of Amazon customers complaining the USB port gets loose and starts disconnecting from the smallest cable movements, and with the weird design choice of putting those little cosmetic dots on the casing by drilling actual holes that allow dust and potentially water to get in. This last one should be fixable with some tape I guess, but for the connection quality or chances of total failure, you’d just have to take the risk, or get it from a store that’s trustworthy with RMAs.
I think you might be confusing the Line Out specifications of 2V for the 3.5mm and 4V for the balanced with some kind of power measurement. Line Out is the spec used to drive some other piece of equipment, and is probably a Line Out mode for the DAC to go into an external AMP.
The specs on the website show 120 mw of output power, and they don’t specify into what load. That’s not bad if it’s into 32 ohms, which is likely. The iFi that I mention is 70 mw into 32 ohms.
The specs on the Dawn Pro do not look bad, but realize that anything drawing power from a phone USB is not going to power HD650 headphones well, although it may drive them to adequate levels. @Torq provided a very concise discussion of this several years ago. At that time I was using a Dragonfly Black. I’ve since gone to a Dragonfly Cobalt, then a Luxury & Precision W4 as dongle. And @Torq was of course right.
If you need to power HD650s properly, you will need something that either accepts some auxillary power or is not particularly portable.
What about the FiiO KA13?
Is there a portable DAC that can power the hd650 for example nicely and work as a soundcard for a laptop?
What do you mean by enough power to drive the HD650s? I’ve used the Anker dongle and at 70% it was getting uncomfortably loud for me.
Are you talking more about possible sound changes due to impedance or distortion?
It’s easier to go to a store site and search for selections sorted by price
https://www.e-earphone.jp/product/search/list/?pageno=1&category_id=945&search_type=0&orderby=6&on_sale_only_display=true
The joker in this deck is the HD650. I have the HD-6xx which is essentially the same headphone. Many of us in the forum have one of them or the HD600 or perhaps the HD 660. All of which have certain similarities.
The HD-650 in particular is notable for scaling. Unlike many headphones to a large extent it will really sound better with better components, both DAC and AMP. Now it’s not going to suddenly sound like a $1500 headphone, but unlike many it will often improve remarkably with a better chain. Use the forum’s search function for Sennheiser HD 600 or HD 6xx and scaling.
These headphones are often kept around as they are good enough and common enough that many headphone guys use it as sort of a benchmark. We all know what it sounds like.
Now these 600 series Sennheisers are 300 Ohm headphones. They are harder to drive than most headphones - the most common being 32 ohm. Yes, you can have a dongle that makes them LOUD, but more power drives them more cleanly. Bass lines that had been muddy become crisp. To some extent it depends on your ears and how carefully you listen. There’s a reason that some use them for mastering.
The limitation of the smartphone is that there is a certain amount of power that can be supplied by the lightning or usb connector.
This isn’t enough to make the HD-650 shine. Look at the “portable” DAC page on headphones.com for example:
Portable DAC/Amps – Headphones.com
Many of the larger ones have a battery supply of their own. The Earmen, The iFi Hip Dac 3, many in that class will do a MUCH better job with your Senns. The specs on the Chord Mojo show you output at both 32 ohms and 300, for example.
Note if you want the additional power of balanced (and the HD-650 sounds good with balanced) you will ALSO need a different headphone cable for the headphones that uses a balanced connection.
So while a dongle type DAC/AMP will power most IEMs and easier to drive headphones, the HD-650 can really benefit from something a bit larger that can either be plugged in or has it’s own power source, not the USB connector.
I power my HD-6xx from a desktop stack, not portable - I’ve stopped trying although it sounds pretty good with the Dragonfly Cobalt or the L&P W4. There is clearly a difference when powered by my Lyr 3, FiiO K9 PRO ESS, or best of all by my Eufonika tube amp.
Thanks a lot for taking the time to elaborate 
I’m not a beginner though, my desktop DAC + Headphone amp combo is a Lynx Aurora (n) which I also use a converter to my Bryston 3B-SST which powers linear nearfield monitors.
Just these mobile DACs is uncharted territory for me and I want to get something that powers my reference headphones well enough on the go that I’m satisfied. I also don’t know how much I gain compared to the amount I’d spend upwards. I’d also like to avoid using something that could damage my headphones. I’m mainly using the HD650, HD6XX, MM-500 and 490 Pro.
FWIW this discount season around Nov. 11th I’m looking to get a FiiO KA17 which has probably good enough cleanliness (officially 0.0004% THD+N but they’ve been open and honest enough lately to publish the graph vs. frequency and you can see it never surpasses 0.001 even in the highs) and power that goes to 650 mW @ 32 ohms, which I expect to hear extracting everything the HiFiMan HE-400i is capable of, or close enough for a portable anyway. Also I trust the THX amps in it are some of the most uncolored available, also I like that they allow me to switch the reconstruction filter to linear-fast even though their unfortunate preference is to set it to minimum-phase by default.
It’s harder to pin down the ‘enough’ point with these headphones that ‘scale’, but basically it’s something to do with imperfect elasticity(?) of the materials where the membranes show more and more resistance to being moved an extra micrometer the farther away they already are from their resting point. So an amp that’s already ‘losing steam’ (dropping off from linear operation) when the HD650’s membrane is getting close to its maximum excursion will not be able to present percussive slams correctly past a certain loudness whereas an amp that’s still in its linear operating range - usually because it’s nowhere near its maximum setting - will do that just fine and give you the same ‘slam’ at high loudness that it could at quieter levels.
For example I was surprised to find that the lowly KSC75 sounds significantly better in this dynamic/slammy behavior when powered by my HiBy FC3 in high-gain (max. 100 mW @32) vs. low-gain (max. 50 mW @32), even though this meant going from a mode of operation that could top it out at 118 dB SPL to 121 dB, both of which are way louder than I would ever intentionally use in actual listening. If we only went by NwAvGuy recommendations we should consider an amp that can drive them to 115 dB peak level to be ‘enough’, but in practice it seems it’s not that simple, it can be worth getting amps that can theoretically push 120+ dB for some headphones.
So in your case if you get a dongle that can do 4 Vrms @300 for the HD650 (and mind you the Dawn Pro is not clearly specified to be able to do this already at 300 ohms), that would only get them to 115 dB (since they’re 103 dB / 1V, it means 103 + 20*lg(4) = 115), but with this being a pretty cheap class of devices we’re talking about, we can easily expect the amp section to not stay linear all the way to its max, so the HD650 will probably show weaksauce dynamics on such a source (and a few user reviews do suggest higher-impedance headphones are not driven to their best by the likes of the Dawn Pro).
For comparison, the KA17 advertises 90 mW @300 for its BAL output, if Desktop Mode is enabled, which should give you 103 + 10*lg(90/3.33) = 117.3 dB, not a lot better, and this is if you’re willing to recable the headphone to “balanced” aka. 4 separate wires + pentaconn 4.4mm connector. Looks like you need multiples of your original intended price to get a dongle that you can be sure will drive the HD650 every bit as well as a desktop unit. Have to pick your battles with these lower-price portables. 
If you’re not a beginner, and you have the budget AND aren’t set on a small dongle, then something like the iFI xDSD Gryphon will work fine. Or the Chord Mojo 2. Or anything in that general range and style that is battery and portable. I used to use the original iFi xDSD and it was borderline, but much better than a DFC.
Please @Lothar_Wolf, @PaisleyUnderground , @generic , or @Resolve etc, jump in here with a suggestion. I was hoping that @Torq might point to his earlier discussion of this subject.
The 650 scales with respect to having enough clean amplification, but also benefits from a high quality DAC, one that has synergy with it. If you are stuck with a dongle form factor, I’d recommend the Luxury and Precision W4, and another interesting choice might be the Woo Audio Tube Mini. Again you will have a choice of single ended or balanced. The Tube Mini offers a power base to get around the limitations of smartphone power output and might be useful also.
I have no personal experience with the Tube Mini, but there are reviews of it here on the forum. It has characteristics that should make it synergize weill with the 650. I do not know the Moondrop personally either - I’m not trying to disparage, but merely point out the limitations of all dongle based DAC/AMP products. I know that electronics get better over time, but the price is suspiciously low.
It’s low enough, that you should be able to just buy it and resell it if you don’t find it adequate. Since you have a good desktop stack, do a critical comparison listen.
I tried a whole bunch of mobile and small desktop setups with my HD-600 between 10 and 5 years ago. I was never happy with anything below the desktop iFi ZenDAC, as it had adequate power, the balanced output cuts the treble noise, and the integrated DAC has the warmth to soften the upper mids. For me, the smaller mobile devices weren’t enough of an upgrade to bother versus laptop/tablet output or the cheap Apple dongle.
I haven’t done anything with mobile battery dongle devices for 5 years or so, as my desktop setups are much nicer and as I now use either the AirPods Pro or IEMs for mobile.
But aren’t these dongles using certain spec chips and then boost the level after that chip had already done it’s own amplification? Isn’t that bad for the sound quality? Seems like double amplification?
From all the YouTube videos and general publications, I was under the impression that nowadays, with all the new DAC chips and devices, you’d be able to power high impedance headphones with small devices.
I’m incredibly happy with the Lynx Aurora (n) with its included headphone amp, it’s sonically surpassing my previous stack and the Oppo HA-1 I used to own. I’ve attached a photo of the specs.
I mean I’m fine with a portable DAC as long as it is clean and doesn’t introduce coloration to the sound.
The Moondrop Dawn Pro seems to be able to do 2 Vrms which would power the HD 650 to a loudness of 110 dB peak and 4 Vrms on the balanced outs, which would roughly suffice for 115 decibels. Have I gotten this right? Shouldn’t that kind of cover the dynamic range for a listen loudness of 80 dB?
Btw still don’t know how to do multi quotes on a phone here 
Isn’t the KA17 re-amplifying the already amplified signal of the DAC chip?
I was hoping that we’ve come to a point where these small devices would actually do ample amplification for the majority of headphones, given that specifications have vastly improved compared to let’s say 6 years ago.
As discussed, it “should”, but in practice it often doesn’t, especially with cheaper amps, especially when they also have other major constraints to satisfy like fitting in the palm of your hand.
Yes, but it has to or it wouldn’t make the HD650 type of headphone sound even decently loud. Every DAC-amp combo does this. As the distortion and noise specs show, it’s not a major problem, the final output can still be kept pretty damn clean, even transparent for everyone’s ears and listening environments.
We kinda have? But not for $50 
(that’s why you’re also getting recommended things like the Luxury & Precision W4) and/or not for “old-school” hard to drive headphones like the monitoring classics etc. Along with improvements in small DAC-amps there has been an evolution toward more efficient new models of headphones and heavy proliferation of even more efficient IEMs. DAC-amp makers now know they will give satisfactory power to 95% of their customers even if they can’t quite power 300-ohm Sennies or 600-ohm Beyers to max performance, because who uses those anymore? (Or who takes them along as portables?) 
Not every DAC amp combo does this but probably the ones that rely on kind of an SoC ready out of the box chip with included amplification.
Most professional converters like the Lynx will have a DAC + analog filtering stage followed by a dedicated headphone amplification circuit that’s not all baked into the DAC chip like all the ESS and CS combos.
I mean, there has to be a line drawn on what’s actually physically rational and what’s just believe. I can’t absolve myself from this fully though since I think the Lynx is the most transparent professional converter to my ears, which took me trying dozens of other converters and years of time. Although when you loopback audio through the Lynx and compare it to other professional converters, something that can be measured, after let’s say 30 passes, that it will still almost phase out perfectly while others take on shapes of their filtering stage.
I’m saying that there has to be some technical specification the headphones require to power their drivers adequately without encountering distortion at the respective playback level in decibels.
I know people like to figure out stuff themselves and feel rewarded when they think they think they hear something different in this field, but most of the time, and I also can count myself guilty of that, it’s a placebo effect and doesn’t actually physically exist or can be an audible indicator of something else that’s not really doing what you think it does.
And let’s say a certain headphone requires this amount of voltage and amperage to be driven properly, and device X is physically capable of that, then no other device with a much higher price will give you a “better sound” besides your preference of possible coloration and possibly low end distortion that makes the sub frequencies more audible.
Biggest problem for me are the unclear specifications of these devices, which I assume is intentional?
No, I meant every DAC-amp that aims to drive “big-boy headphones” has a separate amp stage that re-amplifies the signal coming out of the DAC chip. This SoC stuff seems pretty recent to me, and demanded probably by these exact devices we’re talking about, that have to fit in a shirt pocket or stay clipped to the collar.
I don’t know that anyone has blind-tested the claim that this or that headphone ‘scales with more power’ and established whether there’s an audible benefit to powering such a headphone from amps capable of far more than 115-ish dB or not.
And without losing frequency extension at high loudness (if the notion is that it loses ‘slam’ or transient speed when underpowered I have to assume it’s losing some high frequency capability in the audible region). I don’t know, in theory it should be possible to specify, but I’ve never seen headphone manufacturers including anything about this in the documentation. Hell, most of them can’t even provide clear numbers on sensitivity in dB/V or efficiency in dB/mW and name each one correctly (some of them will give you the efficiency, call it “sensitivity”, and specify it in “dB SPL”, so that’s where we’re at).
Oh absolutely. They have bad crosstalk - they will just not publish it in the specs. They have lackluster max power into high impedance headphones, they won’t tell you the power at high impedances, only at 32 ohms, or will just say mW and not associate them with any load. And so on and so on. Always being unclear or silent about the aspects where they’re not providing attractive performance. Even the Luxury and Precision types with the expensive offerings I’ve caught being unclear about what noise and distortion corresponds to their claimed max power, I think their W2 unit was promising a max power that could only be achieved at 10% THD+N, so they went to the maximum distortion permitted by Chinese law to be associated with the max power you’re promising.
See this link for discussion of L&P W4
This for Chord Mojo 2
This for xDSD Gryphon
The World of Dongles
Again @Resolve @SenyorC or someone else - I get the feeling that this thread has gotten started in the wrong place for people to see and respond and should be in the DAC AMP general discussion.
And no, those bigger devices like the Chord Mojo, Gryphon, etc are not bad for sound.
Yeah they are throwing out these specs of 2 Vrms and 4 Vrms, specify 120 mW for some resistance meanwhile Hifiman provides a sensitivity info without specifying whether it’s dBvolts or dBmw. I can’t even calculate properly how it’ll perform at 300 ohm.
I’m not sure which discussion you’re referring to, but if you give me a few hints I can dig it up and post a link to it.
Normally I’d read the thread to get the context, but I’m just back from three weeks vacation* … and there’s Milton to prep for.
*My wife planned this vacation, and her style of vacationing requires two subsequent vacations for me to recover from.
