No, I do not use a computer. I would like to have a portable unit, so that I can use it while I am on the train, bus and at home.
Smartphone or tablet will be your best bet since you can just download the player app that has that feature.
Some like the Fiio X7 can run on Android mode and you can just download a player app that has it. Note though that these won't have the same level of customer support in case of bugs in the sense of "30,000 Fiio X7 sold, 50 users use this app vs 1,000,000 Galaxy S/Note/xx users that are experiencing bugs on this app." It's like my having a gain bug on Neutron Music Player (this has mono too) on my SGS3 years ago and it took six months before it got fixed. That's already a fairly common device.
One thing about the X7 and X5 3rd gen though: I think Fiio is phasing them out. The M-series is the new line, with lower power compared to the X-series, and AFAIK so far only the M15 can run Android.
You are right: I tried to contact several distributors of HiRes players. No company has player where on the software side you can choose that both stereo channels are summed up.
When you google for "Headphones / def on one ear", you will find a lot of of people asking for this.
I don't mean "few" in that it won't register in a Google search.
I mean something along the lines of my example above on the X7 vs Android phone brand numbers plus my common enough Android phone still taking that long for a bug to get fixed. And that was an app with EQ and Crossfeed so I couldn't ditch it. At least in your case there are others that sum in mono. Bottomline: if even on a fairly common phone it can take that long to fix, you have to have at least two such apps in case one gets a bug and support takes this long.
I mean there's a Manual Gearbox Preservation Society, so that's a lot of people on top of car magazine editors, but Toyota is still phasing out the manual gearbox option for the GT86; Honda isn't clear about what transmission is going on the S2000 replacement (which could be CVT), Lamborghini doesn't want slower 0-60 test numbers so good luck hoping for manual at a time when an auto gearbox and Quattro AWD only have to deal with one unknown variable (the driver's foot ie throttle angle) much less another dog-leg 1-2 shift with Reverse where First usually should be as was last seen on the Diablo...
If you have the disadvantage of being handcaped with only one functional ear, you have to have the best gear to improve the clearness of the sound of music. You all are talking about stereo sound. I do not know, I will never know,- what this means, as I never had a chance to hear it. But I love music. I am 26 years old, studying classical guitar since 19 years and after my bachelor in 2017 I hopefully will pass my exam for the master degree this summer.
Which is exactly my point. Audiophile manufacturers are focused on delivering imaging prowess, among other things, but there's a reason why they're not thinking about adding mono-summing into player software other than a few DAPs or player apps (like, don't expect a home audio server to do that): once you have an identical signal on both channels instead of two distinct signals everything shifts to the center. There won't be a real distinction between cymbal to the left or right of the drummer's seat, guitar 1 vs guitar 2, how a piano is recorded so somebody
It's really only this problematic with headphones since each ear hears only one driver. If you're using speakers, not that it will be the exact same thing as with two ears, but there's still going to be some semblance of imaging with just say a balance control. Your ear will still hear the sound coming from the other side, in-room, and get positional cues, you just bias the loudness a little bit off to that side. Of course, the problem here is you'd either have to install one in a car if it's mobile or at home which will be effectively fixed in that location.
So, back to a headphone solution...if you don't want to use a computer, you can use a smartphone with a player app that can do this. Choose a decent smartphone like LG since the power of the Quad DAC circuit gives a fair bit of flexibility in choosing what you can use with it. If you really don't want to use Android or LG's Android overlay, but are wary about the support limitations on running a Chinese DAP running Android (nor getting a Korean player), then just get a player app with this feature for whatever phone you use (assuming it isn't Apple so you can expand the storage capacity) and hook it up to a DAC-HPamp that will give you less distortion and more power than the phone's audio chip.
Now if you really want a DAP for some reason, there's still a work around. You don't need mono-summing on the fly, but you'll have to put in some work and use music editing apps on the copies of music you have and convert them all to mono.
Pros:
1.This will work with any player, including whatever fancy DAP you might want to get
2. Not running it on DSP saves CPU processing on your playback device, so the battery life is longer.
Cons:
1. You need a separate harddrive (that way you can keep the stereo files and use them for speaker systems)
2. It doesn't work on streaming services, even if you download the music from there.
