[SolarCetacean]

Balanced output will generally have 2x the output impedance of unbalanced. That's not unusual. The amp designer would need to use an entirely separate output circuit on the balanced output to have an OI that's the same as the unbalanced. Balanced also has 2x the noise, because there are two output devices. The only real benefit of balanced output (as opposed to balanced interconnect) is the greater output power (up to 4x) and voltage (up to 2x) from differential signaling, if the amp's voltage rails and power dissipation can handle those levels.

As to whether that OI is a problem, only if you're dealing with extremely low-impedance headphones that also have large impedance swings. Keeping to the rule of 8ths, if you have a headphone/IEM with an impedance of above 16 ohms and has no significant swings in the impedance curve, I don't think you'll have a problem. Note that having a high OI can sometime produce pleasant effects (like boosting a particular FR region) with certain headphones even if it's technically inferior.

 

[Pelilin]

Balanced output will generally have 2x the output impedance of unbalanced. That's not unusual. The amp designer would need to use an entirely separate output circuit on the balanced output to have an OI that's the same as the unbalanced. Balanced also has 2x the noise, because there are two output devices. The only real benefit of balanced output (as opposed to balanced interconnect) is the greater output power (up to 4x) and voltage (up to 2x) from differential signaling, if the amp's voltage rails and power dissipation can handle those levels.

As to whether that OI is a problem, only if you're dealing with extremely low-impedance headphones that also have large impedance swings. Keeping to the rule of 8ths, if you have a headphone/IEM with an impedance of above 16 ohms and has no significant swings in the impedance curve, I don't think you'll have a problem. Note that having a high OI can sometime produce pleasant effects (like boosting a particular FR region) with certain headphones even if it's technically inferior.

What happen to the sound if the IEM is under 16/19ohms? Problem is i dont know what is the impedance of my IEM and the company doesnt want to release any info on it.

 

[Vamp898]

What happen if the IEM is under 16/19ohms? Problem is i dont know what is the impedance of my IEM and the company doesnt want to release any info on it.

Doesn't matter. The XBA-4 has 8 Ohm and works just perfect too.

 

[MrNailhead]

I saw this question asked a couple times but nobody ever answered - does the 707 have a dedicated Line Out setting for the balanced 4.4mm output? It doesn't seem like it does from research, but hard to tell sometimes. Thanks.

 

[povidlo]

I saw this question asked a couple times but nobody ever answered - does the 707 have a dedicated Line Out setting for the balanced 4.4mm output? It doesn't seem like it does from research, but hard to tell sometimes. Thanks.

707 does not offer line out option.

 

[Mmet]

I agree with all of what you wrote except this ...

Balanced also has 2x the noise, because there are two output devices. The only real benefit of balanced output (as opposed to balanced interconnect) is the greater output power (up to 4x) and voltage (up to 2x) from differential signaling, if the amp's voltage rails and power dissipation can handle those levels.

Actually balanced amping (when real ) has many benefits beside the more power out put ... They provide LESS noise by better noise rejection.. better SNR values ...
and for sure less crosstalk with better center imagining ( each channel has its separate positive and negative amplifiers compared to shared ground negative lines for unbalanced amps ) all of that with their higher power capabilities .

What you have wrote in that paragraph actually is the typical issus of Double amping not balanced amping

 

[Haden2866]

Interesting thread - a real rollercoaster ride! I've ordered a nearly-new, uncapped JP ZX-707 from a private seller on fleabay UK - should be here in a day or two.
I'm really interested to experience the Sony house sound - a lot of people seem to like it, and I'm glad to see that the firmware appears to be moving in the right direction now, SQ-wise.

I've only owned one (arguably) mid-tier DAP, a Cayin N3 Pro - I enjoyed the amp section but felt that the DAC implementation was a little uninspiring. You'll see from my signature that I currently own and enjoy a couple of Cayin dongles that eschew the delta-sigma approach, and I have a small desktop DAC that uses an old Philips multibit TDA1543 - this last one is mercurial; it usually sounds OK, but can occasionally astonish with a really holographic, out-of-your-head experience (some sort of phase coherence effect that I can't reliably reproduce).

So, as someone who appreciates alternative DAC architecture, I'm looking forward to what the ZX-707 can offer, both in direct mode and with some of the DSP enhancements - the vinyl emulation sounds interesting, having read the designer's notes that someone was good enough to link to on this thread.

My use case will be with a new set of single beryllium dynamic driver IEMs - Flare Audio EARS, which ought to arrive in the next few days. A few pages ago someone was bemoaning a lack of innovation in dynamic driver IEM design - Flare claim to have solved for chaotic sound reflections in the inner ear - let's see; early impressions appear mostly favourable in terms of SQ. There's a short Bluetooth 5.2 cable that comes with this set, so I'm looking forward to seeing how LDAC performs with the ZX-707.

I've also got a pair of Avantone Pro Planar headphones on the way. I intend to convert these to balanced. so I'll be interested to see whether the ZX-707 can drive these effectively, with 240mW (IIRC) from the 4.4mm output. Just about enough, I would expect.

The relatively long battery life of this DAP is, for me, part of its appeal, as is Android 12 - I'll be using Tidal as well as playing local FLAC files. I'm looking forward to trying UAPP, and to see how it performs with my RU6 and RU7 dongles with USB out, for when I might be in the mood for a different flavour.

I'm no Android expert, but will be making some of the user-level OS optimisation tweaks that have been mentioned here and elsewhere. I'm hoping that performance will allow for some light web browsing, as I currently use my work phone for that and will be relieved to have an alternative.

I'll need a case - the Miter case is available from a well-known, next-day delivering, online outlet, so that seems like a good option. If anyone who has one wants to venture an opinion on its quality and fit, then that would be helpful.

So, thanks to everyone who has contributed to this thread. I'll try and add my own impressions, once everything has burnt in and become familiar.

My expectations are for this to be a quality mid-tier DAP, with some good design and ergonomics, as well as some retro cool Walkman appeal, highly tweakable sound based on an enjoyable Sony house sound profile, good battery life, and a good-enough user experience, if the user puts some effort in to optimise the OS.

 

[zenki]

Well I use/d chi-fi dongles before. After zx707 there's just no coming back. Period.
But it's a lie. Still use them sparingly.

 

[Haden2866]

Well I use/d chi-fi dongles before. After zx707 there's just no coming back. Period.
But it's a lie. Still use them sparingly.

It's good to have options. Sometimes a different flavour is just what you need.

 

[Pelilin]

After a while owning zx707 i can honestly say comparing to hiby r6pro ii it actually powerful enough to power any IEM in the market(uncapped version). The problem for people coming from Chifi is that most chifi products have this colored SQ that make music engaging/fun or energetic. Some who is used to these chinese DAP/Dongle might think that what they are listening is colorless but actually it is not. After i use zx707 i now know what near colorless is and it reproduce music as is. First time using i thought it is boring but after a while it is very pleasant and you can listen to music for longer period of time. Maybe i can compare it with drinking flavored liquor or drinking it without any flavorings. Chifi have its own niche im sure but sony SQ are for people who want to listen music as is. ZX707 have a very dark background and the sense of room and realism of vocal is top tier imo. Vocals is not in your face it is like sitting in a room while the singer singing in front of you on the stage. Well everyone experience might be different but overall im pleased. Anyway after burning in 200hours the sharp upper mid and treble is totally gone.

 

[zenki]

"the sharp upper mid and treble is totally gone."
Never had this issue from the start.

 

[Vamp898]

"the sharp upper mid and treble is totally gone."
Never had this issue from the start.

That sounds like an headphone/earphone issue to me^^ when i plug an HD800S into my WM1ZM2 it always sounds painfull to me, no mutter how much burnin^^

 

[MudEnjoyer]

I haven't noticed any difference myself after 200h. But I didn't burn it in on purpose, it was gradual as I used it.

Compared to the Q5K I barely can't tell a difference in terms of tonality. The ZX707 seems to sound a bit softer (unless you play with DC Phase effect), but I haven't bothered volume matching or doing proper A/B testing. I simply like the comfort of having a DAP and carrying my library around.

The only thing it's missing IMO is a proper PEQ.

 

[Pelilin]

Nope i only have 1 earphone. Well maybe burn in is just a myth and my brain is the one getting used to how sharp it is at first. Or maybe the earphone is the one who need burn in? I dont know. Now i wonder why some people here suggest to burn in for 200hours what is the purpose of that?

 

[Vamp898]

Nope i only have 1 earphone. Well maybe burn in is just a myth and my brain is the one getting used to how sharp it is at first. Or maybe the earphone is the one who need burn in? I dont know. Now i wonder why some people here suggest to burn in for 200hours what is the purpose of that?

The reason you burn in the ZX707 is to stabilize the power output of the capacitors. Its biggest impact is in the bass region and especially in the first few hours.

I had access to an non burned in WM1ZM2 and an burned in for a short time and the differences are surprisingly small, but they are there and they are audible and are, in my experience, mostly if not exclusively in the bass region