[dbmathis]

Hard to tell.

People tend to describe the sound out of the Mojo being practically magic, not just "I can hear more bass because of a blacker background/higher current performance/more voltage," since in two of those possible reasons it won't be true compared to a good desktop amp, but really just outright magic that in some cases I don't think it's the power or the clean signal but start to suspect it boosts certain frequencies.

Kind of like how Grado frequency response is all over the place but it sounds more "real," ie, the percussion gets boosted in just the right way (plus the high sensitivity gets it loud easily without hitting bad distortion and noise levels) so it really sounds lik the band was shurnk down and is now is inside your head.

That's the thing. The only thing I have to compare to is a pair of PC360s that was gifted

I don’t want to complicate what has become a jumble of recommendations for all sorts of gear, however, I want to point something out for your reference in the decision making.

While the Mojo 2 will do a decent job it is technically at its best into a headphone with low impedance rather than high. Its maximum power output is into only 8 ohms and at 300 ohms of the HD600 it puts out only 90mw and something around 5 volts.

It will work just fine and will get plenty loud but I would not have thought it was anything close to a universal recommendation for a DAC/amp to make the most of the HD600.

Something like the rather more modestly priced iFi Zen Can is designed more with power output into a higher impedance load and puts out much more power into 300 ohms and something like 3 times the available voltage.

I use an iFi Diablo with my HD600 and it drives them exceptionally well despite being a battery powered DAC/amp. I would recommend one in principle but at the price it isn’t really a good starting point in your situation.

Of course you would need a separate DAC but iFi has several offerings and you could put together a little desktop stack for far less money than the Mojo 2 that is on paper better suited to the high impedance HD600.

Even the very modestly priced Zen Dac V2 would be a great starting point on its own and could provide DAC duties in a Zen Can if you wanted to try more power.

To make the most of these you would need a headphone cable with a 4.4mm balanced plug but they are easily available at all sorts of prices and you would have money left over versus the Mojo 2.

Just food for thought.

https://ifi-audio.com/products/zen-can/

https://ifi-audio.com/products/zen-dac-signature-v2/

https://ifi-audio.com/products/zen-dac-v2/

https://www.audiosciencereview.com/forum/index.php?threads/ifi-zen-can-review-headphone-amp.25224/

I've decided to keep the HD600s, for now, and am now in search of the best possible DAC/amp combo for them. My primary focus is field recordings, so I need equipment that is durable, versatile, and accurately reproduces sound for later editing in Izotope. Portability is essential, as I often carry my gear while walking. Although I aim for superior quality, I'd like to remain cost-effective, but there is not budget. I don't want to spend an excessive amount needlessly. The PC360s served me well, but now that they've reached their end, I'm keen on finding something as good, if not better. Listening to my raw recording in Izotope rather than YouTube this morning convinced me that the HD600s will likely suffice for the headphones, but I need to hear them through a good dac/amp to be sure. The ultimate goal as of today ? A DAC/amp combo that captures reality with utmost precision. Music appreciation, though a bonus, is secondary for me.

For example: Here's one of my recordings. I just switched between the PC360s (which have a popping sound due to the loose mic) and the HD600s. They are plugged directly into a Macbook Pro. The PC360s sound better by FAR. With the PC360s I feel like I'm walking the road as if I am there. The thunder clap is awe inspiring. The HD600s sound weak and artificial compared. I lack the experience to explain the difference I hear, but it's night and day. I'm thinking they are just underpowered, but I'm just not sure:

 

[Monsterzero]

It will work just fine and will get plenty loud but I would not have thought it was anything close to a universal recommendation for a DAC/amp to make the most of the HD600.

I agree, but I'm trying not to overwhelm the OP by insisting he run out and buy a tube based OTL amp right away, especially if he isn't even sure the HD600s are to his liking or not.
There are approx 30 headphones, give or take, that excel with an OTL, whereas the Mojo 2 will drive pretty much every headphone out there except for the Abyss 1266, Susvara, HE6 and the Tungsten and a few other power hogs im forgetting. If the OP loves the HD600 out of the Mojo 2 and decides it's a keeper and wants to squeeze more out of it, then I'd recommend an OTL amp for it, plus he can continue to use the Mojo 2 as a DAC and run a line out of the Mojo into an OTL, so the Mojo will continue to be relevant in his chain.

 

[earmonger]

"Portability is essential, as I often carry my gear while walking."

Forget the tube amps and all the desktop recommendations. And, alas, forget the VE Megatron. You'll need something battery powered.

Since the HD600 are open backed, you may not be able to wear them for monitoring while field recording because your sensitive mics will pick up the playback. Of course, if you're not wearing them while recording, it's no problem.

 

[dbmathis]

"Portability is essential, as I often carry my gear while walking."

Forget the tube amps and all the desktop recommendations. And, alas, forget the VE Megatron. You'll need something battery powered.

Since the HD600 are open backed, you may not be able to wear them for monitoring while field recording because your sensitive mics will pick up the playback. Of course, if you're not wearing them while recording, it's no problem.

It could just be that I’m not being a clear communicator. Basically I wear binaural mics and film walks. I carry other things with me, like my my laptop, to listen to what I’ve recorded afterwards. I would not be monitoring while recording because I record 32-bit so clipping isn’t a thing. I can pull down the gain in Izotope post. I’m kind of learning as a go in this thread about DACs and amps and what is best suited for my needs.

I did just order a pair of HD599s too to see if they are at least equal to the PC360s.

I’m second guessing the Mojo 2s until I’m sure it’s the best for my needs for the HD600s.

I’ll do side by side comparisons to the PC360s, HD599s and the HD600s through a amp/DAC combo.

 

[earmonger]

If you're using the laptop, the VE Megatron is an inexpensive, powerful and well-spec'd DAC/Amp. Seriously, check out the threads on Head-Fi.

For field recording you want an accurate, un-colored sound, not a "musical" one, not tube distortion.

I also have a Schiit Magni 3 -- desktop, AC power -- and they sound different, probably because the Megatron is using its own DAC as well as the amp power. But I'm happy with either one.

I listened to some of your video through my Megatron and my beloved Audio-Technica ATH-R70X, an open-backed headphone that was designed to one-up the Sennheiser HD650.
https://www.theverge.com/2018/7/6/17535412/audio-technica-r70x-review-professional-headphones

Thunderclap at 13:30 sounded great, birdsongs and footsteps and raindrops were very clear and realistically located. If you're trying and returning multiple phones, they're worth a try too.

 

[dbmathis]

Here’s my plan folks. Thoughts?

The PC360s are failing. They have an issue with the mic causing popping sounds, but they're still reliable enough for comparisons.

I'll be using the headphones exclusively with my Mac lineup: Mac Mini M2, 2019 MacBook Pro i9, Mac Studio MAX M2, and iPhone 15 Pro Max.

Today I purchased the HD599s and I still have the HD600s.

To evaluate the HD600s, I bought the K5 Pro DAC/amp combo.

I'll be comparing the PC360s, HD599s, and HD600s when paired with the K5 Pro. If the HD599s are comparable to the PC360s, I might consider returning the HD600s and K5 Pro. However, if the HD600s, when paired with the K5, provide a noticeably better sound than the HD599s, I'm leaning towards the iFi Audio iDSD Diablo as a permanent solution for its fidelity to the true sounds of recordings. I've read about support issues with the Mojo 2, which makes the Diablo more appealing. In that scenario, I'd likely return the K5 and opt for the Diablo while keeping the HD600s and returning the HD599s.

 

[cfranchi]

Here’s my plan folks. Thoughts?

The PC360s are failing. They have an issue with the mic causing popping sounds, but they're still reliable enough for comparisons.

I'll be using the headphones exclusively with my Mac lineup: Mac Mini M2, 2019 MacBook Pro i9, Mac Studio MAX M2, and iPhone 15 Pro Max.

Today I purchased the HD599s and I still have the HD600s.

To evaluate the HD600s, I bought the K5 Pro DAC/amp combo.

I'll be comparing the PC360s, HD599s, and HD600s when paired with the K5 Pro. If the HD599s are comparable to the PC360s, I might consider returning the HD600s and K5 Pro. However, if the HD600s, when paired with the K5, provide a noticeably better sound than the HD599s, I'm leaning towards the iFi Audio iDSD Diablo as a permanent solution for its fidelity to the true sounds of recordings. I've read about support issues with the Mojo 2, which makes the Diablo more appealing. In that scenario, I'd likely return the K5 and opt for the Diablo while keeping the HD600s and returning the HD599s.

See those videos before going the rabbit hole:





My guess is that you want something more spicey and holographic sounding than HD600 (even if HD600 is not bad at imaging) : Hifiman Sundara would meet your requirements.

 

[dbmathis]

See those videos before going the rabbit hole:





My guess is that you want something more spicey and holographic sounding than HD600 (even if HD600 is not bad at imaging) : Hifiman Sundara would meet your requirements.

Thanks for sharing those videos on not going down the rabbit hole. I watched them! Interestingly, that's precisely why I'm opting for a more affordable amp/DAC combo initially — to determine firsthand whether the HD600s truly shine with additional power. I'm keen on gauging this based on my personal experience, not just others' opinions.

If I do notice a marked improvement, I don't intend to settle for the K5 Pro. My preference is not for a desktop amp but something portable, low noise, and designed for robust headphones. That's where the iFi Audio iDSD Diablo seems to excel. I was initially drawn to the Mojo 2 due to positive reviews, but concerns about their customer support have made me hesitant. Devices like the BTR5, or in the same class, just seemed underwhelming on paper.

On the flip side, if I do NOT perceive a significant enhancement, I suspect I might not have the same affinity for the HD600s as I do for the PC360s. That's why I've also ventured into trying out the HD599s. My speculation is that they might be more aligned with the sound profile of the PC360s, referencing the 50 ohms spec they both share. The primary reason for wanting to replace the PC360s with another Sennheiser model is my absolute love for their sound — it's sheer perfection to my ears. If this pans out as I anticipate, I'll return the HD600s and the K5, having spent only $100 USD to find a successor to my PC360s.

I'm venturing a guess that I might not witness a significant difference with the HD600s even with the amp/DAC. However, what's giving me reason to pause is the fact that I must max out the volume on my Apple devices to even hear music on the HD600s. Especially when I listen to something like The Planets - II. Venus, The Bringer of Peace - Gustav Holst, which is WEAK even on the highest volume when streamed lossless from Apple. it's possible that what i don't like about the HD600s is the lack of power reaching them, especially compared to the PC360s 112dB SPL at 50 ohms. But again, it's essential for me to listen with ample power and decide based on my personal experience.

Lastly, while it's conceivable that I could have varied preferences for different headphones depending on the situation, my immediate goal remains clear. I'm primarily looking for replacement headphones that resonate closely with the PC360s sound, particularly for my field recordings.

And if your weren't familiar with the PC360s before my post on this forum, you are now! They were an amazing headset and headphone!

 

[megabigeye]

If I may add another voice to the maelstrom of opinions?

1) The headphone out on Apple products are actually very good. I use my M1 MacBook Pro and iPhone 12 mini with my HD 650 and Beyerdynamic DT 1990 all the time with no complaints. That said, the HD 600 are 6dB lower sensitivity than the HD 650, which means they need 2x the voltage to reach the same loudness. If you're able to get loud enough without maxing out the volume, then I wouldn't worry about an external amp right now.

2) Unless you're running into clipping, more voltage/power doesn't make things sound better, it just makes them louder. Full stop. That's not an opinion or an observation, it's just the way transducers and electricity interact. That's not to say that two amplifiers won't sound different from one another, but that it's not a difference in voltage/power that's making that difference. If you're not listening at ear-damaging levels, you're using less than 1 volt and a fraction of a milliwatt, even with the HD 600.

3) If you are serious about keeping the HD 600, I think you should spend some time listening to them exclusively. Don't switch back and forth, don't do comparisons. You're used to the specific way your old headphones sound, and you need to give your brain time to adjust and become accustomed to the way the HD 600 sounds. Give it time. It could take a few hours, it could take a few weeks. Heck, with some of my headphones it took a few years.

4) A new amp isn't going to change night into day. It might add a subtle flavor, but if you don't like the HD 600, I don't think the Mojo or FiiO amps are going to change that. (Unless what you're really after is just a louder listening level, which can make things seem preferable.)

5) I don't generally like binaural recordings and I don't have any experience with recording or production, so take this with an appropriate amount of salt. I don't have the HD 600, so I can't test your video with that, but listening with the HD 650 and DT 1990, things just don't quite sound right. Unnatural, as I think you said. The rain on your umbrella in particular sounds more like random static than it does like rain. With both of those headphones, it took several minutes of listening before my brain accepted it as rain. When I use my Oppo PM-3 (sadly out of production), the rain sound was immediately more realistic, it took basically no time for my brain to adjust. The thunder was also much more awe inspiring with the PM-3, especially during the low rumbling. I think you can go two directions from those observations: a) if what you want is to enjoy the way your recordings sound, then maybe the HD 600 isn't for you; or b) if what you want is to make the sounds more realistic to more listeners, then maybe the HD 600 (in addition to another headphone?) could work.

 

[earmonger]

Regarding the "This Is Fine" dongle video -- bah humbug. I got an Apple dongle after seeing that and reading other reviews, and it is too feeble to run my ATH-R70X out of the phone. There's a reason amps exist.

 

[dbmathis]

Regarding the "This Is Fine" dongle video -- bah humbug. I got an Apple dongle after seeing that and reading other reviews, and it is too feeble to run my ATH-R70X out of the phone. There's a reason amps exist.

If I may add another voice to the maelstrom of opinions?

1) The headphone out on Apple products are actually very good. I use my M1 MacBook Pro and iPhone 12 mini with my HD 650 and Beyerdynamic DT 1990 all the time with no complaints. That said, the HD 600 are 6dB lower sensitivity than the HD 650, which means they need 2x the voltage to reach the same loudness. If you're able to get loud enough without maxing out the volume, then I wouldn't worry about an external amp right now.

2) Unless you're running into clipping, more voltage/power doesn't make things sound better, it just makes them louder. Full stop. That's not an opinion or an observation, it's just the way transducers and electricity interact. That's not to say that two amplifiers won't sound different from one another, but that it's not a difference in voltage/power that's making that difference. If you're not listening at ear-damaging levels, you're using less than 1 volt and a fraction of a milliwatt, even with the HD 600.

3) If you are serious about keeping the HD 600, I think you should spend some time listening to them exclusively. Don't switch back and forth, don't do comparisons. You're used to the specific way your old headphones sound, and you need to give your brain time to adjust and become accustomed to the way the HD 600 sounds. Give it time. It could take a few hours, it could take a few weeks. Heck, with some of my headphones it took a few years.

4) A new amp isn't going to change night into day. It might add a subtle flavor, but if you don't like the HD 600, I don't think the Mojo or FiiO amps are going to change that. (Unless what you're really after is just a louder listening level, which can make things seem preferable.)

5) I don't generally like binaural recordings and I don't have any experience with recording or production, so take this with an appropriate amount of salt. I don't have the HD 600, so I can't test your video with that, but listening with the HD 650 and DT 1990, things just don't quite sound right. Unnatural, as I think you said. The rain on your umbrella in particular sounds more like random static than it does like rain. With both of those headphones, it took several minutes of listening before my brain accepted it as rain. When I use my Oppo PM-3 (sadly out of production), the rain sound was immediately more realistic, it took basically no time for my brain to adjust. The thunder was also much more awe inspiring with the PM-3, especially during the low rumbling. I think you can go two directions from those observations: a) if what you want is to enjoy the way your recordings sound, then maybe the HD 600 isn't for your; or b) if what you want is to make the sounds more realistic to more listeners, then maybe the HD 600 (in addition to another headphone?) could work.

Once the amp and HD599s arrive today, I'll have a clearer perspective. I trust my own ears when making these decisions. If the HD600s paired with the amp don't give me a truly immersive audio experience and the HD599s do, I'll likely return them. However, I'll test them with music from Pantha du Prince, Aphex Twin, and some classical pieces first. If I don't keep them now, I might reconsider for specific music purposes in the future. This has been a good learning experience.

 

[Monsterzero]

That's where the iFi Audio iDSD Diablo seems to excel. I was initially drawn to the Mojo 2 due to positive reviews, but concerns about their customer support have made me hesitant.

FWIW, I bought the original Mojo 2nd hand several years ago. Eventually the battery died and one of the outputs failed. Even though I had a 2nd hand unit, with no receipt and it was out of warranty, Chord fixed it free of charge. Once I got it back I sold it to my buddy in Arizona, who still uses it.

Regarding the Diablo, I do not recommend any gear that I don't have experience with, which is the case with the Diablo. It could be better than the Mojo 2 or not. I have no idea, but at least in my experience, Chord's customer service is outstanding.

 

[dbmathis]

FWIW, I bought the original Mojo 2nd hand several years ago. Eventually the battery died and one of the outputs failed. Even though I had a 2nd hand unit, with no receipt and it was out of warranty, Chord fixed it free of charge. Once I got it back I sold it to my buddy in Arizona, who still uses it.

Regarding the Diablo, I do not recommend any gear that I don't have experience with, which is the case with the Diablo. It could be better than the Mojo 2 or not. I have no idea, but at least in my experience, Chord's customer service is outstanding.

Here's where I read the part about the Mojo 2 customer support. Look under "Final Grade": https://homestudiobasics.com/chord-mojo-dac-review/

The article reads:

1. It runs hot. This isn’t too big of a deal for most people including me being that it’s a Class A amplifier.
2. For many people, the battery fails to hold a charge – usually around the 1-year mark or before.
3. Customer support seems to be non-existent in many cases.
4. The unit dies unexpectedly or behaves erratically.

There was another review, which I can't find, where people in the comments were saying the battery died and customer support was charging them 200.00 to replace it. They were swapping the battery out themselves to save money.

 

[BS5711]

I think you can go two directions from those observations: a) if what you want is to enjoy the way your recordings sound, then maybe the HD 600 isn't for you; or b) if what you want is to make the sounds more realistic to more listeners, then maybe the HD 600 (in addition to another headphone?) could work.

Interesting observation and extension of that.

I listened to the recording with a few IEM that sound very good with music. I didn’t bother getting my HD600 out but probably should have.

I also didn’t find the recording anything particularly special, convincing or awe inspiring even at the thunder claps.

That the begs the question, what does our chap want from his recordings and from the headphones he listens to them with ?

If all that is required is personal listening pleasure then use whatever floats your boat, frankly why not just use extensive EQ to make them sound even better.

If listening to essentially judge how good the recording is for others to listen to then surely one judges the recordings and makes changes based on listening with a more “monitoring” set so that the recordings are more aligned with what others will listen with and provide a better chance of them getting the best from the recordings.

 

[dbmathis]

If listening to essentially judge how good the recording is for others to listen to then surely one judges the recordings and makes changes based on listening with a more “monitoring” set so that the recordings are more aligned with what others will listen with and provide a better chance of them getting the best from the recordings.

Thank you for taking the time to listen to my recording and sharing your thoughts.

While I understand the value of aligning recordings with what most might use for playback, it's challenging to determine a universally accepted reference. I mentioned earlier in the thread – which is quite extensive, so I completely understand if it was overlooked – that the PC360s offer a more realistic playback for my recordings compared to the HD600s, imagining and soundstage mimicking what I heard when I was there.. For me, they serve as an excellent reference set. Beyond this, they've been exceptional for general music playback as well. While I'm not averse to using them for various purposes, my primary focus remains on their utility for my recordings.

Your feedback is immensely appreciated. Insights from audiophiles always offer a fresh perspective and help me refine my approach.