[superuser1]

I did about 100 hours on normal listening volume, not too loud, almost minimum level on the A3, connected to an X1. This is the same volume I listen to them on. I let them rest for a few hours every day I was burning them in last week. I haven't bumped them or damaged them physically in any way, I was pretty careful with them through and through

Should be good with 100 hours.. I hope someone else is able to shed more light on this.

 

[CoiL]

Maybe somehow gear matchup problem? Or is it consistent with every gear and same song? What quality song file is (CD or Youtube)?
I haven`t heard any weird sizzles or distortion yet and I listen lot of progressive rock.

 

[SMRDcompany]

Yeah I tried a lot of things; I switched L and R on the cable to see if it changed anything because I mostly hear it on the right channel, but it sometimes happens on the left, too; it happened all the same, on the same channel so switching individual units was kind of inconclusive; I tried fitting the right IEM into the left ear and vice versa for the same reason, the fit wasn't ideal but I'm still not sure, I think nothing changed so between the two drivers I think both exhibit this, I just happen to hear more of it on the right channel. It might be the cable but I have no way to test this as I don't have a backup MMCX cable (though I'm not sure how a cable might do this),

I tried hooking it up to the laptop straight up and played the same files, with the same result. The files are high quality FLAC from 80s rips, original 90125 master which was a pretty good and clean master (for Owner of a Lonely Heart which I mentioned). It might be just the way they sound and I'm a bit too sensitive to this. I've had a pair of cheaper Sennheiser IEMs a long time ago on which the right IEM exhibited something similar, although I could always reproduce it with the sound of a piano, which covers a lot of the spectrum. With these, every instrument sounds clear at times, but sometimes vocals and distorted guitars sound like the speaker has been blown...the volume doesn't matter, I can hear it on the lowest volumes as well...I will see if it randomly goes away with usage, I tried cleaning out the tips and nozzles, I'll try using different tips as I'm using foam tips right now, might have something weird to do with that, no idea in general. I don't know how good Penon is about returns but I might have to contact them about this. It did seem weird to me that the package wrap came undone when I opened the package, though I assumed this was due to the customs opening the package to check it...I also cannot seem to locate a warranty card, not sure if IT01 comes with one in the box or if that is supposed to be sent separately and Penon didn't send me one...I'm more confused than anything, might have to contact Penon first before deciding on what I'm going to do. If it does sound like this, I can live with it, I suppose, but it is pretty distracting when it happens. My main problem, aside from the warranty stuff, is whether this is intended sound or my unit is broken...I don't want to take another $35 for customs clearance just to have the same unit returned to me, if it is in fact working fine

 

[SMRDcompany]

Maybe somehow gear matchup problem? Or is it consistent with every gear and same song? What quality song file is (CD or Youtube)?
I haven`t heard any weird sizzles or distortion yet and I listen lot of progressive rock.

Oh, and just to add to my previous post, I listen to a hell of a lot of prog too, but I don't think I've heard it in prog, yet. A bit in The Snow Goose by Camel at only one point, but it could be the record itself as it's a bit grainy. Even on Tubular Bells, which has a lot of distorted guitar work, it sounds absolutely clean. It mostly happens on 80s era distorted guitar sound.

 

[CoiL]

My unit from Penon came with 100% untouched package wrapped in shrink-plastic which was unopened.
About sound problem You are having - maybe IT01 is so revealing in some frequency and You are too sensitive to it? And lot of 80`s rock/prog has certain "sizzle" with analog guitar effects.

 

[quodjo105]

It01 with the wm1a in balanced is so delicious. I should have bought these earlier. For £76 ,no complaints here ..

 

[VitalyAverin]

I have to say that these are very good, but I have quite a bothering problem - around 10kHz (but goes from 7-12kHz) I feel an excessive boost which is leading to vocals (most of female and higher-pitch male vocals) being somehow...grainy(??), feeling a bit distorted. A touch of sibilance too.
Should not be the case of a source, I use Dragonfly Red, which is shall not be "bright".

Can anyone confirm similar findings?

I do confirm. Mine was changed by local shop lately. So, I have the same feeling and it's more obvious when it's new. My DAP is fiio X5 III now. A month ago I had Colorful C4 and felt the same.

 

[jamato8]

I don't have any grain or frequency issues. I wonder if it is something that should be looked at by iBasso or if someone is having issues, if they shouldn't be exchanged. I use all types of music, from western, acid, hard rock, jazz etc and no issues.

 

[kukkurovaca]

Hmm, for those experiencing the 10khz issues, are they at all tip or source dependent? I haven't noticed anything, but I've been doing a lot of my listening with EQ that cuts a bit around there.

 

[Paul - iBasso]

I have not been able to reproduce issues in the 7 to 10 khz range. If you have a song that does this could you use WeTransfer to send it to me at paul@ibasso.com? I would like to know if I can hear the problem.

 

[SMRDcompany]

I have not been able to reproduce issues in the 7 to 10 khz range. If you have a song that does this could you use WeTransfer to send it to me at paul@ibasso.com? I would like to know if I can hear the problem.

Will do in a bit. I have two examples in my mind right away which clearly show the issue. To me though it really sounds like my unit is faulty, especially since I think it happens more on the right channel

 

[starflyer]

I also noticed an excessive boost at around 10 kHz and I am sensitive to that. Check it at http://onlinetonegenerator.com/frequency-sweep-generator.html. Comply tip tames it a bit. A wide bore tip (e.g. spiral dots) shifts the boost to around 8 KHz and I am fine with that. I do not see any measurements being posted except the one from the manufacturer. I have more than 100 hrs and I tried with multiple sources.

I have to say that these are very good, but I have quite a bothering problem - around 10kHz (but goes from 7-12kHz) I feel an excessive boost which is leading to vocals (most of female and higher-pitch male vocals) being somehow...grainy(??), feeling a bit distorted. A touch of sibilance too.
Should not be the case of a source, I use Dragonfly Red, which is shall not be "bright".

Can anyone confirm similar findings?

 

[icefalkon]

I've never had any problems with my IT04's.

 

[Youghin]

could iPhone drive it well?

 

[superuser1]

could iPhone drive it well?

As has been said before the IT01s are very easy to drive at Sensitivity: 108+/-2dB