Basshead approved, as these can go deep into the subbass region. All the while the mids and highs stay unaffected. By now you know these Hybrids have one woofer and 3 BA’s. The woofer fires into a tube, which filters out the higher frequencies. Thus, no crossover needed and one less thing to worry about.



How does it sound? That is hard to describe in words. Other reviewers have described the sound signature very well, compared to how I would describe the FH5.

I would describe these FH5 like, they are as capable as the JVC SZ2000. Deep subbass, clean mids and highs. Responds very well to EQ, just like the SZ2000. This to me is a big deal, as I like to listen to a wide variety of music with mostly one headphone or IEM that doesn’t cost an arm and a leg.

The other nice thing about these FH5 are, that you can change the Fiio "In-House" sound with just a simple cheap cable swap. I’ve tried a few and let my son and friends verify that there is a change in sound signature. So, you basically pick the supplied or your own ear tips that work for you and after that just roll cables that are cheap enough on Amazon to experiment with. I personally and my son do not like supplied FIIO cable that comes with the FH5. The cable and connectors look nice, but it is hard and just doesn’t sound “right” for us.



So, for me I like plain old copper wires for these FH5. I would choose cheap Mogami copper wires if you can build your own cables. If not, the 20-30-dollar cables on Amazon will do. My son prefers the cheapy 20-dollar 6 core silver plated wires from Amazon. These are the black cables in the picture.




Comparison done with;
Michael Jackson "Wanna be starting something". DSD 2.8

Fiio Q5 AM3B 4.4, Fiio FH5 w/Fiio foam tips

6 Core wire copper:

Vocals are more prominent (more forward) vs the 16-core silver copper mix. Midrange is more distant. Bass levels are the same. Description by the seller: The sound is exquisite, clear, full and round and full of analytical force, be rich, more detailed. Improve bass and mids. Light weight and pliable to ensure that wearing is solid and comfortable.


8 Core copper:

Vocals stayed with the midrange. Midrange and vocals complements each other. Bass is same as 6 core copper. (Vocals take a small step back). Description by the seller: This copper upgrade earphone cable increases texture and gains more depth in bass, makes the mids more warmer and sweeter. Gains a bit more brightness in highs. Increases the soundstage.
I like this when listening to stuff from Phibes.


16 Core silver-copper mix:

Vocals and midrange are emphasized (a bit louder) vs 8 core copper. Sound is more Vivid. Description by the seller: Using this 16 core copper and silver hybrid replacement cable, can really aid in definition of the previously overshadowed elements. The cable provides a slight bump in resolution and a noticeable increase in clarity throughout with more extended vocals and clearer layering of instruments. The cable’s separation did provide the impression of a larger soundscape. Detailing and high-hats are enhanced. Soundstage space slightly increased and separation was greatly improved with better resolution of background details.
I like this cable when listening to stuff like UB40


6 Core silver-copper (black) wire mix:

Soundstage is much wider vs the other cables. Back vocals where further back. Depth increased. Description by the seller: This upgrade earphone cable delivers a considerably more defined, articulate bass response through greater linearity and resolution. The greater mid-bass control of the SPC cable forms a cleaner bass presentation that enhances delineation between notes.


Stock Fiio LC-3.5 B cable:

Soundstage not as wide as the black cable, but wider than the rest. Depth not as deep as the black wires. Mid to Low is not as prominent as the other cables. Mids to Highs doesn’t really sound balanced. Cable doesn’t do the FH5 justice.


4 Core copper silver mix, with silver back end:

Vocals are forward and everything else takes a step back. You feel like you are further away from the stage.


4 Core copper mix long, with silver back end:

Midrange is further back. Vocals and bass stood out more.


4 core copper Mogami with silver back end:

Everything sounds more aggressive. Soundstage increased, almost as wide as the black wires. Bass has more impact than every other cable.


Norne audio copper 3.5mm with silver back end:

Soundstage got wider, but still not as wide as the black wires. Sounds similar to the 8-core copper.

I received this unit for evaluation purposes and to post my opinion on this forum and such.



From day one the Burson Play sounded great from the get go. After 24 Hours it sounded it even better and finally settled after a few more days. Funny how that works at times.

The unit gets pretty warm, but that is to be expected for it being a class A unit. Even the volume knob gets a bit warm after a while. I can see that you will need a well ventilated PC chassis, when using this amp inside a PC.

Build quality is pretty good. Fitment issues here and there are minor, which is ok for the price range. But at the higher price range with the other opamps being offered, I would expect better QA. This is me being picky and having high expectations in my work environment.


I don’t hear any of Sabre “Glare” that I have heard before with other units using the same DAC. Sound is well rounded and I don’t feel an opamp upgrade is really necessary to enjoy this amp unit. Subbass is bottomless and controlled. Midbass is tight. Midrange is clean and the high-end is proper to my ears. I don’t hear 17 kHz and up as well anymore, so in my regular audio setup that range is a bit boosted to compensate for my natural roll off in the higher frequencies. But as far as I can tell, the topend sounds really really good. This amp is HiFi-Basshead approved!

Compared to my Parasound desktop setup, I feel the “Play” can hang with the best of them out there on the market. Even with the so called high-end home units, when it comes to the Dac department.




The sound is basically perfect using my favorite JVC SZ-2000. Power to spare and zero lack of dynamics. Streaming Funx radio stations, the sound coming from the Play is impressive. Totally different from my older Dac/amps. My volume is set around 16 out of 99, unless I go a bit crazy with the subbass and then the volume goes up. Playing DSD and Flacs the sound gets more impressive. Quite astonishing what Burson has done within this small platform and price range.

The sound with the installed NE5543 and NE5532 has the Burson sound signature already. Upgrading opamps after that is pushing out the absolute best out of the amp. And that is where you enter the HiFi audiophile level and the money pit starts to get deeper.

The output coming out of the RCA connection provided in the back are not fixed, but variable. So you could hook up the Play to an external amplifier or the Burson Bang.

The motherboard has a well thought out clean layout.


Preference:

I really like the sound signature of the FIIO Q5 AK dacs over the Sabre, but by a very small margin. I mean if the Play offered changeable Dac filters, it would have been perfect in that aspect.

Instead of changing filter settings on the Dac itself, Opamps rolling is offered for changing the sound signature to your liking.

It’s like me upgrading my Dac chip inside my Ibasso D7 to Wolfson 8741. The sound improved over a big margin and I am perfectly happy with it. It’s still in my rig and gets used quite often. But the newer stuff sound even more analog vs the 8741. It comes down to sound signature preference now. There is no better Dac per se. This is good news for us.



Wishes:

That the Play did offer an RCA input like the Burson Fun unit. But this Play is geared towards PC users and not really desktop usage.

That the remote be included even for the basic unit and not use for the ones with the opamps upgrade already installed.


Other user’s comments;

User #1

The Burson Play has more impact and is more forward sounding. Sounds really good with Rock music. Very enjoyable to listen too. He can only imagine what an opamps upgrade would do to the sound. Says it sounds as enjoyable as his Sony PHA-3


User #2

Sounds so natural as opposed to the “digital” sound that he is used too.


User #3

Very interesting sound. None fatiguing and smooth. Not crazy about the looks of the chassis. Would’ve liked a nicer looking power supply, instead of the supplied power brick.


User #4

Loves the sound and is impressed with the “guts” of the unit. Interesting power stage and board layout. He would’ve liked a “balanced” output as another feature.

Charles at Burson provided me samples of the V6 Classics for my opinion in my setups.

Equipment used are:

Ibasso PB2 with 8 buffers in wide bandwidth mode. Extra Wima caps on the opamps and upgraded the stock caps. Power supply used is at 16.8V.
Ibasso DB2 Dac with Muses 8832 opamps.
Various iem's and JVC headphones.
Player is Foobar, with Bootsy VST and GEQ-7 VST.


So, I installed the pair of classics into my Ibasso PB2. They sounded way to sharp when plugged in. It toned down after a bit of use. Burn in I'm guessing....

I feel that the V4 Burson's are still my favorite in the low-end department. Love those opamps!

The V5i sounds really nice in the PB2. Nice smooth topend. Non fatiguing. Lowend is snappy when needed. And these are my daily drivers for portable use.

The V6 Classic sounds really good in the PB2. Too bad it's a portable unit. I can't close the case with these V6's installed. My fav JVC headphones sounds even more like my old home stereo setup, which consisted of B&K components, ADS and B&O speakers. I can only imagine what these opamps will do in the Parasound equipment once I get another setup. I'll update this review once I get another Parasound Zamp and Zpre setup.

So with the previous Burson opamps, I heard an improvement in the overall sound with burn in. The V6 Classic kinda behaves like my old B&K amplifier. It sounds it's best once it get warm. Kinda cool I think. So I don't think long burn in is really needed with these opamps. But rather warming it up for a bit, true use. Or never turn off your setup, like I use to do with my home setups.
The V6 Classic vocals come out more to the front. Instruments are better separated. The highs are more pronounced, but non-fatiguing. The bass is there when called for. So easy to close your eyes and just jam away with your fav tunes.
For bassheads like myself, the Classics are worth having over the V5 and V5i's. Subbass goes deep, clean.

Details.....the finger snapping in the beginning of Man in the Mirror by Michael Jackson are so pronounced.
Vocals in On a Mission by Phibes are so smooth, with no sharp edges.
Blue by Marina and the Diamonds is so enjoyable.
Gravity by Maxi Priest sounds proper. Instruments are so much more detailed.
Departure by Hotei bass lines are so well blended.
The 24-36hz bass notes in Bass Airwaves are so clean. Zero distortion.
The male and female vocals in Majestic love by Gyptian and Estelle are so well defined.
J Boog male slight harsh vocals in Love me are so well produced.

I was given this Cable+ by Charles @ Burson for my opinion and review.

First thing I did when I received the Cable plus, was opening it up and see what's up. I'm pretty impressed with the enclosure. Real metal and decent cables were used. So I can see where the money went into. But $150 is a bit steep for this gadget and that is just my personal opinion. I don't know what Burson put into R&D to get this on the market and still making a profit over time.



Burson recommended burn in time, so I let it burn in for a few days straight. It never got warm and an improvement was heard after only a few hours.

So the Burson V5i is the secret to this little "upgrade". I was iffy on whether or not it actually worked. I felt it was low budget preamp of sort when I first heard about it. So why not just get yourself an preamp I thought. The Cable+ is mostly to connect between the low power devices like your phone, tablets, laptops and whatever you use for amplification. In this scenario it performs very well. I used a little 7" HP table, HP laptops and PC's and in return I got bigger headroom. It was hard for me to point on what the Cable+ sounds like with these portable devices. I can hear an improvement in detail retrieval, but not much. I then used it between an Iphone 4s and Nokia 1520. Huge improvement on the Nokia using Foobar. The Iphone 4s sounds good by itself using various players, so only a small improvement in micro details to my ears.

Next up was hooking up the Cable+ in my desktop rig at work. I connected the Cable+ between the Ibasso D7 Dac and Aphex 124A. The Aphex is a Balanced to RCA and Visa versa converter that is used for the DBX Gorack.
In this setup the Cable+ works out best. The D7 is pretty good for an at work DAC. With the Cable+ inline the my work soundstation sounds like my at home Headphone station, which consist of a Parasound ZDac. My mind just blew. I didn't have to "suffer" anymore. To think I was going to solder in a new opamp inside the D7 to get better results. The Cable+ avoided me doing all that work. I got all the sweetness to my headphone heaven in two setups now. The Cable+ added a Reference tone to the Ibasso D7, completing my mission. I can now use the same EQ settings at home and at work with my headphones.

Cable+ in between the D7 and PB2 Ibasso's.


Cable+ Permanent home on top of the Zamp V3, which has the Burson V4 in there. The Zpre preamp also has the Burson V4 installed. I might sound like a fan boy, but the Burson V4 is great for subbass reproduction on top of detail retrieval. It's a step above the Muses02 in my rigs.



Messed around with the Cable+ some more.
The Aphex 124A boost up the gain just like the Cable+. The Aphex is cheaper on the used market and adjustable on the fly. What goes in, is what comes out. With the Cable+, what goes in, isn't what comes out. It's "cleaner/leaner" depending on your portable source. Ofcourse there are limitations. If your source is crap, well crap gets amplified and you will be really disappointed in what you hear. The Cable+ I haven't really seen on the used market, so I don't what the market value of it will be over time. It not being on the used market yet, means people really like the Cable+ once they have it and tend to keep it in place.

So far the best overall improvement comes from the Ibasso D7. I used a Fiio E7 and E17 line-out, with so so results.
I wonder if I could upgrade the opamps to V5i in the Aphex to get the same results in a simpler audio setup.......


Update 11/29/17
So my Cable + got effected by the Texas flood and the connectors where just soaked in muck. I got rid of the stock cables and upgraded to the same cables I use on my IEM's, Headphones and interconnects. I've should of upgraded the stock cables way before. The stock setup sounded very clean and robust. Now it's on a different level and enjoying it all over again. It's worth the cheap upgrade for those willing to solder.

I found one cheap for 100 bucks and decided to get it for the balanced out capability.  I already have a D7 Ibasso that I used on a nearly daily basis, so why not try out a PB2.
In stock form it sounded great from the single ended output. Swapped out to the WB 634 buffers and two Muses02.  Great combo, but it was still lacking something.  It didn't sound as nice as my desktop amp, which is the Zamp V3 with Burson V4 in it.  I made an adapter for the Hifiman and man what a difference in sound in "balance" mode.  Sound is twice as loud vs single ended.  Soundstage has more depth,  width, and clarity like Zamp amp.  Ofcourse it doesn't play as loud as the Zamp, but you can't complain on what this little amp can do with the planars. Supposably it can output a total of 5W into 32ohms.  IFI can do 4W @ 16ohms.  Not bad for this old amp.
 
The nice part is that it comes with dummy buffers.  Nice to have when you want know how your Opamps really sounds like.  And like the Burson Lycan, you can test both single and dual opamps.
 
Specifications:
Power Source：Built-in 12.6V Li-Polymer Battery Pack, or 16V External Power Supply
32V voltage swing
Frequency Response: 10Hz~150 KHz -0.5dB
Signal to Noise Ratio：-115dB
Output power：Up to 2500mW+2500mW into 32Ω
Gain: +6dB/ +12dB/ +20dB (Balanced Output)
Gain: 0/ +6dB/ + 10dB (Single End Output)
4-layer gold plated PCB 
Battery Life: >20 Hours
Battery Charge Time: 4 Hours Recommended. 80% when the red light goes off. 2 hours after that it's fully charged.
Has overcharge protection
When the furnished AC adapter is connected, the PB2’s battery is bypassed
Headphone Impedance: 8~600Ω
Case dimension: 2.2W x 3.9L x 0.95H (inch) 55W x 1001L x 24H (mm)
Weight: 168g or 5.9oz 
 
I think 100 bucks is well spend on this amp.  The Ibasso P5 cost way more and for the full potential, you still need to buy the stand alone PSU.  I haven't had issues with short run time with my PB2 unit, even though it's a few years old already.  Also using 9V batteries for a portable amp in this day of age, is just plain ridiculous.
 
Changing gain is a bit of a hassle, as you have to open up the unit to access the jumpers.  
 
Wired up the TRRS plug like the pic below.  This way I can still use the headphone in a regular single ended output.  I found the pic here on the forum.
 

 


 
 
Ibasso D7 as Dac, feeding the Pelican directly.
 

 
 
Update 3/5/17:
 
I swapped out the stock 1200uf 16V cap and stuff in dual 1800uf 16V caps instead.  Subbass is cleaner.
 
In single ended mode, I stacked the Buf634 with good results.  Subbass got cleaner with the JVC SZ2000.
For fun I stacked the Buf634 WB on top of the Buf634  for balanced mode.  Bass got better with the Hifiman, but doesn't sound as nice with just the Buf634 WB installed.  The JVC SZ2000 got the same type of subbass boost, but didn't sound as nice as with the regular stacked Buf634.  But you quickly forget about what you are missing once you start jamming away.  The JVC's are powered properly now with the underrated Pelican.
 

 

Messed around with the Elear and too bad it has to go back.  
 
Very fancy looking headphone and has a nice solid feel. Fits nicely on my head and the thick long cable is not of an issue for me. I use heavier cables with my Hifiman.  
 
Sound is very nice, especially with string instruments.  Bass is very good and so is the "subbass".  I used Bootsy Rescue MK2 to push this headphone to the next level.  Sound stage, impact just became heaven.
Design and finish is great. It does creak a bit, but that isn't an issue once it's on your head.  
 
Bad news is that the unit I messed with just didn't cut it above 57% volume on my PC.  With zero EQ the driver starts to pop on the right side with volume above 57%.  Not acceptable for unit in this price range.  I have zero tolerance for this kinda crap from manufacturers that think it's ok to send out units with this kinda fault at this price range.  
I feel the headphone is worth 400 if it worked ok and not the price that are asking for.  
 

 
  
 
Update 3/1/17:
 
I received a new Elear and guess what.  No driver issues this time around.  Therefore one star gets added on.  It's still overpriced for what you get though.
The headphone does not response to EQ and such like my Hifiman and others.  So you are stuck with a narrow range of music genres.  
 
My wife says that it sounds very clean and she was bopping her head while jamming on her tunes.  She likes it as much as the Hifiman 400i on the musical side, but she wishes it had the impact the Hifiman has.  
I had some more people listen to it and all agreed on how well they like the sound, but wish there was more impact.
 
On the new unit, bottoming out the driver took some more effort listening to the same tracks as before.  
For my ears I had to use DBX goRack, setting 5 to enjoy the headphones even more with reggea/dancehall music.  One hour flew by with and had no fatigue.
 


 

 

 

If you are a bass head and still like to hear to rest of the music, then this Burson V4 could be for you.  
 
Charles at Burson had offered the V5 in exchange for a honest evaluation.  I did and got hooked on the V5 in my Parasound preamps.  However the V5 didn't do too much in the Parasound amp of mine.  After all it's a great designed and well put together little unit, using JRC's opamps.  I got a Gustard with the V4 as a loaner and stuck the dual V4 into the Parasound Zamp V.1.  I was blown away with what I heard. 
The size of the unit can be a problem.  40mm x 16mm x 20mm For the dual and 40mm x 16mm x 14mm for the single.
 
 
The V4 is on a different level vs the V5.  To my ears with the JVC SZ1000, the sound gets more depth with the V4 vs the V5 when I installed it inside the Parasound amplifier.  I can now also use the full range of the preamp volume control, without getting into the distortion zone.  I've played 24bit and 16 bit Flac's containing Metallica "Metallica" album, DJ Danny Bled, Damian Marley, Amy Vachal, Bass 305, Phibes DNB, Hotei Strangers, Sade,  DJ Russticals, Gary Howey, Robert Miles and lots of others.  Where the V4 truly shines is in the subbass department.  You hear it as your are suppose too.  It's effortless, clean and goes deep.  
 
From Burson's website:
 
"Unlike the general-purpose IC opamp designs which focus on high open loop gain, Burson aimed to achieve low open-loop distortion, low noise, low drift and low offset. The Supreme Sound Opamp also exhibited a wider bandwidth and wide power supply range. These qualities are essential in high quality analog audio amplification.
 
The input stage features a pair of carefully matched field-effect transistors. Each pair of transistors went through two stages of screening to ensure best possible matching. The main amplification section employed a current mirror configuration instead of the conventional voltage amplification. By keeping the current limiting resistor to a minimum value we minimised RC parameter of the circuitry, and hence achieved a wider frequency response.
 
Another pair of matched output transistors is coupling with the emitter follower stage. This arrangement ensured high driving current and low output impedance, which made the SS Opamp suitable for a wide range of audio applications."
 
So is it worth getting the V4?  Well it's not a straight answer.  It's a trial and error kinda deal, since not every piece of hardware is the same.  It's pricey that is the other thing, but so is every piece of high end equipment.  Component selection is key. Component matching cost money and that is what your are paying for.  In my case, the V5 is worth the upgrade in the Parasound Zpre and the V4 in the Parasound Zamp V.3.
 
In the Gustard H10 the upgrade to Burson V4 are worth the money.  The amp get put out plenty of power and with the Burson's puts it up there with the other high end audio devices.  The Burson dual do run warm, but the singles not as much inside the Gustard.  Adding Wima caps to the single opamps made a difference, but nothing with the duals.  With the Burson's installed the sound of the Gustard comes pretty close to the B&K PT5 preamp of mine, which is quite amazing.  
 

 




 
Making paper vibrate at 15Hz

 

I was given a pair from Burson to evaluate the opamp in my setup.  I posted my finding in this other thread http://www.head-fi.org/t/830082/parasound-and-burson-adventure .
 
I first heard the V4 Burson opamps in fellow forum members Gustards H10.  I was amazed at the detail that came out of my music with the Burson's installed.  But the size wasn't ideal for my portable setup and just stuck with the Muses series opamps.  But I upgraded my work music station to something better and started rolling opamps again.  At some point I got contacted by Burson after posting some of my pics and tweaks in my Parasound setups.  Parasound has a sound signature that I enjoy for headphone use.  I enjoy the Parasound way more now with the V5 Burson's installed.  
 
To my ears the Burson are few steps above the Muses02, Muses01.  Musical, alive, spacious and non-fatiguing.  
 
Burn-in really matters with this upgrade.  The sound changes as the hours go by and it sounds great once it has settled.  The EQ settings that I have been using, had to be changed with the Burson's. The Sonic Maximizer that I had been using for that extra umph, could now be eliminated.  I now have a headphone setup that sounds just as nice my home setup.  
 
 
 
 
 

The Zpre is a dated small form factor preamp from Parasound, that also happens to be a great headphone amplifier.  It comes with the Burr Brown 2134 Opamp for those that care for this type of thing.  It does have rack ears, so look wise it's not for everyone.  These can be had for cheap now, so why not give them a try right.
 
Sound wise, it's the classic good stuff. Musical and none fatiguing.  Nothing you can complain about when choosing equipment from great audio designers.  I actually have two of these little Preamps and to have some more fun, I put in a 8 pin dip socket for Opamp swapping.  Having the remote makes it easy to raise the volume, when you sitting on a couch or something.  The remote that comes with it, also controls an old Parasound TDQ150 tuner that sounds quite good. I drive IEM's and my JVC SZ1000 just fine. I do use software and hardware EQ with this Preamp and it has no problem going in the low notes.  It doesn't have enough power for the HiFiman 400i, but that is why I have a modded Parasound Zamp V1 for.  Some of my other sound equipment are B&K, NAD, Luxman, A/D/S, B&O to give you an idea of what sound signature I like.
 
The look is dated and the younger crowd might just dislike the look and rack ears.  The latest version is  the Zpre 3 that came out this year(Sept 2016).    
 
(from the manual)The Zpre headphone output is driven by a high-quality headphone amplifier circuit. It is suitable for headphones with an impedance of 8 Ω or higher. The headphone circuit remains live, even when you press the Mute button. The Bass control boosts and cuts low frequencies +/- 8 dB at 100 Hz. The Treble control boosts and cuts high frequencies +/- 8 dB at 10 kHz. 
 
The BB opamp can be swapped for a change in sound.  I put a 8 dip socket in two of my Zpre's.  One has the Burson V5 and the other Burson V4.  I also tried the Muses 01 and Muses 02.  
The Burson V5 is very clean and brings the Parasound on a different Hifi level.  The Burson V4 beats the V5 in subbass reproduction. 
 

1. Four Audio Inputs
2. Four Video Inputs
3. Automatic Input Priority Switching
4. Two Audio-Video Outputs
5. Fully Remote Controllable
6. External Infrared Remote Control Input
7. Remote Control Also Operates TDQ-150 Tuner
8. RS-232 Serial Connection
9. DC Trigger Input
10. DC Trigger Loop Output
11. Bass and Treble Controls
12. Motorized Volume Control
13. Low Noise Circuit
14. High Current Power Supply
15. Gold-Plated RCA Jacks
16. Removable IEC AC Cord
17.  
18.  
19. Frequency Response:
        5 Hz Ω 100 kHz, +0/-3 dB,
20. Total Harmonic Distortion:
        <0.003%, 20 Hz 20 kHz
21. IM Distortion:
        <0.005%
22. TIM:
        Unmeasurable
23. Maximum Output:
        9 V before clipping
24. Input Impedance:
        10 kW
25. Input Sensitivity:
        200 mV +/-5%
26. Signal-to-Noise Ratio:
        > 102 dB, A-weighted > 93 dB, Unweighted
27. Maximum Hum:
        > 0.01 mV
28. Crosstalk:
        > 76 dB, 20 kHz
29. Video Frequency Response:
        - 3dB @ 45 MHz (100 kHz - 0 dB reference)
30. Dimensions:
        9 1/2" W x 1 3/4" H x 7" D (2 凡 high with feet)
31. Power Requirements:
        110 V - 120 V AC, 8 W

 


 
 

It would of gotten a 5 star rating, if it wasn't so expensive.
 
So I got to listen to the MOJO yesterday through the JVC SZ1000.  Total different animal of an amp.  Nice clean subbass, while staying musical.  MOJO sounds like the good stereo equipment from the 70's and 80's with the JVC's plugged in. You can hear all the little details in your music.  I think it's worth 350,- , but not the current asking price.  Looks like a child's toy, but feels solid. 
Still amazes me how well the JVC responds to EQ and on different equipment.  I've been "remastering" some of older music and been using the JVC's for that.  When I listened to the MOJO, my old music sounded like they were remastered by me.  Stereo image is a tad wider, has a bit of BBE/sonic maximer effect going on.  Mojo for the win.
 
I used the MOJO as a dac only most of the time.  Didn't like the sound signature as much, which is a personal thing.  So I used line out mode and send the output through the FIIO's and Parasound equipment of mine and liked it way more.  The biggest difference in sound quality for me, is when playing my music from the Iphone through the MOJO.  Huge difference in sound quality.  Mojo for the win again.  
 
Subbass is really really really clean.  Sounds like a pair of 18" EV horn loaded subwoofers.  MOJO for the win yet again.  
 
Hearing all the little details in my music with the MOJO, reminds me of when I use my old Luxman C12 preamp.  The Luxman is a big dinosaur and the MOJO is the evolution of it.  So with the MOJO you get the T-Rex sound,  from a unit the size of a house lizard.  Mojo for the WIN!
 
 
 

 

 

 

This is my second round with these "holy grail" of headphones.  First time around I was just laughing at it's meager power capability.  The sound was good, but not mind blowing.  Zero sub bass control, with ok bass.impact.  I got the Hifiman 400i and couldn't be any happier.  Has everything that I'm looking for at an "affordable" price.  I got a lot of heat from my fellow headphone enthusiasts for my nonesense.
 
  I listen to all kind of music and DO NOT like to be limited to what I can listen too from my music library with an expensive headphone.  For 300+ dollars I want my subbass and bass with authority.  At the same time I want it to be super smooth with stuff like Enya, Enigma, Grace Memo, etc.  
 
So back to the HD650.  It sounds really good when hooked up to my EQ and sound processor.  Without them it just sounds ok with EDM and such.  I don't need to repeat what others have already said about how good it sounds with their music library.  I'm just saying that with modern music, this headphone takes just more than an amp and cable upgrade to eek all the sound out that it's capable off.  For less money you can get a headphone that can do more with less hardware.  
 
So I hooked up the HD650 to the NAD 2140 amplifier speaker output.  Resistor value of around 347 ohms in between headphone and amp.  Sound goes through my good ol' Ibasso D7, into Henry engineering Matchbox, through Behringer virtualizer, Rane EQ and then through the NAD.  That is what it took to get the best out of the HD650 to get the sound out that comes close the the Hifiman 400i that I jam on most of the days.  The subbass came out and the bass had good impact.  The mids and highs are always there ofcourse.  But Sjeesus, I can enjoy the Hifiman with a smaller amp, whereas I can't really enjoy the HD650 without all the other stuff.  
 

These headphones will let you know if your source is good or not.  I won't repeat much of the pros and cons of this headphone that hasn't already been said.
 
These are really comfortable for hours at a time, both in ergonomics and sound.  Bass goes deep, Mids are nice and Highs are sweet.
Bass doesn't have impact until you use an EQ or other sort of sound processor, along with a good amp.  I drive mine through an old school NAD 2140 amplifier.  I drive these hard enough for the grills to rattle.  Some of the stuff I listen too just isn't produced right and the Hifiman will reveal it to you and shove in it your face. Hence why I use an EQ and such.  Because without them, the 400i will make you start to hate some of your music selection.
 
Bass goes deep and has lots of detail.  Shove some good power through the 400i and enjoy the good head massage these planar drivers can produce.  And don't forget the nice soundstage that these open headphones have.
 
Comfort is as good as the HD650.  You can easily forget that you have them on and the hours just fly by.  Now if you want to hear manly bass, the HD650 isn't for you.  The HD650 is the Prius, whereas the 400i would be the Aston Martin when you consider the power capability between these two headphones.  The HD650 will hit its driver limit with a FIIO E12A!  That is just sad.  Pardon me, while I wipe a tear......from laughing.
 
Are there better sounding headphones out there?  Yes sure.  But you will spend way more money for a little bit of gain. But that is just my opinion and the complain box is already full.
 
Personally I don't think these are worth 500 bucks.  More like 400 max and that includes the box it comes in with.  
 
 
 
3/1/17 update:
I've put the JVC SZ-2000 "protein" earpads on the 400I.  Impact greatly increased and the total sound changed for the better.
 

 
Below are my current EQ setting on the DBX goRack

 
 
Foobar VST settings.

I recently upgraded my 16GB version to 64GB for less than 200 bucks.  I wanted to upgrade to the newer models, but I'm not going to waste my money on something that can play the same music for more money.
 
Anyways,  the sound from the Iphone 4s is excellent to my ears.  It's gets better with different audio apps in its stock form.  You don't need to hack it, to unlock it's full audio potential.  Just buy some apps and call it a day.
So my first app that I enjoyed for a while, was the Denon audio app.  You can make your own eq curves.  Sounds really good without an amp.  
Second app is BBE Pro.  This app will bring out the bass along with sound stage, when hooked up to an amp.  Love this app with my bass heavy mp3's.  
Third app is Kaisertone.  This app will give you a 30 band EQ and a few DSP's.  This is my favorite to play Flac files with.  
Once is a blue moon I'll use Neutron.
 
Now I listen to my music a few ways. 
1. Through the 30pin connector, into my FIIO E12A.
2. Through the audio out, into my FIIO E12A.
 
The first method you get what you get with FIIO L9 or L11 connector.  With the L11, you have to choice to use your own cables and charge/sync at the same time.  But I can't barely tell any SQ differences between cables.
 
The second method you get get to hear a difference in your cables you use.  Friends and myself can hear SQ differences when swapping cables.  I like this for when I want a mechanical EQ just to tweak my sound faster depending what I listen too.
 
 
 
 

Great little amp that I purchased used. Driver installs on Win8.1 and 7 with no problems. Using the D7 with my Sony MDRV6 on my work PC. Sony headphones have some foam added in the chambers. This little amp sounds really smooth over the the pc output. Running it on low gain with Bass enhancement enabled in the speakers properties. I'm using the VLC player and bass is set at 7.9db @ 60hz and the preamp set at 5.5db. Perfect settings for me to enjoy bass heavy music and not getting fatigued after 4 hours of jamming. I like it as much as the FIIO E12A. The design shows it age, but still looks new when I received it. I recommend this little amp if you just want something better than what your PC can produce.

Update 2/3/17
I'm still using this little amp, but strictly as a DAC through the RCA output. Still plays every genre of music well. It feeds music to a Parasound preamp and Parasound amp. I've tried using the coax out and no issues there too. For fun I had all three outputs feeding(front aux out, rear RCA, rear Coax) through different units and it didn't complain.


Update 1/22/18
I finally updated the dac chip to 8741. What a huge difference it has made. Sounds very analog and way more detail retrieval. Worth the upgrade for those still using this nice little unit.

I've had these for a while.  I got them for the mic for my phone.  Before these I used the Lil Jamz, which are the same thing without the mic.  Pricewise they are cheap to find now. Design is nice to me.  Isolation is pretty good, but comfort is a hit or miss for me.  Took me a while to find the right fitting with the supplied pieces.  
 
My music source is mainly from my minidisc players or my Iphone.  These don't have the bass as the Turbine version, that I also use.  But I can't complain as I won't cry about replacing a set if they break for whatever reason.  I use the Denon player app on my iphone for the the nice EQ that it provides.  The Jamz sound good with the EQ setting that I use.  But they do sound better with an amp attached to the iphone.  The bass gets more intense, but don't go as deep as the Turbines.  
 
Amps that I use:
FIIO E12A
IBasso D7
Topping TP32