That's a bummer.The output impedance of the R6 is still reported to be 10 ohm by the engineering department. Looking at schematics there's a fixed resistor in the signal path of that value so the logic from which output impedance is derived seems pretty fixed and straightforward.
The output impedance is what it is. Low-Z earphones with impedance swings will have their FR "shaped" to some extent according to voltage division rules. The upshot of that could be beneficial or bad for any given pair of earphones depending on the earphones' tuning at 0 ohm OI (e.g. we could have a BA set sounding dull / dark at 0 ohms yet with an impedance upswing in the treble range; the 10 ohm OI would then brighten up the earphones nicely. The opposite can hold true of course).
As far as driving ability is concerned, the 10 ohms are there precisely so that the TPA6120A may drive the lowest-Z earphones without distortion or instability. So theoretically low-Z earphones work "well". Damping factor is a term to be reserved for damping of driver resonances; low-Z IEMs have no such thing but have ear canal resonances which are not treatable via damping factor. The technical issue that remains then is the frequency response change noted above. Consult your earphones' impedance response curve and frequency response curve. Do frequency response peaks meet with impedance response dips or vice versa? Therein lies the answer to whether the R6 can complement your low-Z earphones. No impedance response data? Take a roll of the dice--or take advantage of the advanced tone shaping functions (the MageSound 8-ball) to be added to the R6 exclusive version of HiBy Music.
Finally, one indisputable benefit of a bit of output impedance is that they make low-Z earphones less sensitive to the amplifier, which reduces amp noise. When an amp has 300mW on tap even at 32 ohms and the multi-BA low-Z IEM in question has like 120dB / mW sensitivity, this is no trivial matter. For example I was testing a FiiO E17K headphone amp (0 OI, 200-odd mW into 32 ohms) against the R6 with one such pair of IEMs. The R6 sounded brighter with said IEMs, I was ambivalent about the merit of this for said IEMs. But the E17K hissed. Not just a little bit, but quite noticeably even at minimum gain.
Well, that is all I have to say on the subject for now. Whatever you decide, I'll be here waiting, listening to some happy tunes on my R6
With early seasons' greetings,
Joe
It would be interesting to see how it compares against the Fiio x7 m2
192 of Dre shows green and DSD shows pink/white on power button.
Pretty Cool
The output impedance of the R6 is still reported to be 10 ohm by the engineering department. Looking at schematics there's a fixed resistor in the signal path of that value so the logic from which output impedance is derived seems pretty fixed and straightforward.
The output impedance is what it is. Low-Z earphones with impedance swings will have their FR "shaped" to some extent according to voltage division rules. The upshot of that could be beneficial or bad for any given pair of earphones depending on the earphones' tuning at 0 ohm OI (e.g. we could have a BA set sounding dull / dark at 0 ohms yet with an impedance upswing in the treble range; the 10 ohm OI would then brighten up the earphones nicely. The opposite can hold true of course).
As far as driving ability is concerned, the 10 ohms are there precisely so that the TPA6120A may drive the lowest-Z earphones without distortion or instability. So theoretically low-Z earphones work "well". Damping factor is a term to be reserved for damping of driver resonances; low-Z IEMs have no such thing but have ear canal resonances which are not treatable via damping factor. The technical issue that remains then is the frequency response change noted above. Consult your earphones' impedance response curve and frequency response curve. Do frequency response peaks meet with impedance response dips or vice versa? Therein lies the answer to whether the R6 can complement your low-Z earphones. No impedance response data? Take a roll of the dice--or take advantage of the advanced tone shaping functions (the MageSound 8-ball) to be added to the R6 exclusive version of HiBy Music.
Finally, one indisputable benefit of a bit of output impedance is that they make low-Z earphones less sensitive to the amplifier, which reduces amp noise. When an amp has 300mW on tap even at 32 ohms and the multi-BA low-Z IEM in question has like 120dB / mW sensitivity, this is no trivial matter. For example I was testing a FiiO E17K headphone amp (0 OI, 200-odd mW into 32 ohms) against the R6 with one such pair of IEMs. The R6 sounded brighter with said IEMs, I was ambivalent about the merit of this for said IEMs. But the E17K hissed. Not just a little bit, but quite noticeably even at minimum gain.
Well, that is all I have to say on the subject for now. Whatever you decide, I'll be here waiting, listening to some happy tunes on my R6
With early seasons' greetings,
Joe
And the N5ii, if you get he chance. Thanks
That would be an obvious compare.
![20171207_015529_001[1].jpg](https://cdn.head-fi.org/a/10038546.jpg "20171207_015529_001[1].jpg")