I moved up to the HE-6 phones from the HE-500s due to the fact that the 500s did'nt "scale well" with the Burson Soloist for me. I'm glad I tried the HE-6s as their reach into the lower frequencies & layering of sound is at a higher level for my listening needs.
It seemed that when using the HE-500s that was unable to find an "ideal" volume setting with 85% or better of what I listen to on my system. What I would normally settle on was either a setting that was a step below being "fully engaged" with the sound or a step above this level to a listenable level that would lead to shorter listening sessions due to ear fatigue. I have or/had amps that have been easier to find that volume , but at the sacrifice of a collapsed soundstage or rolled off treble (Lyr) or uninteresting SolidState characteristics (Beyerdynamic A-1). What to do ? I think the mistake is trying to match a too efficient headphone to the Soloist. I had the same type of results using a pair of Sennheiser HD700s(very similar to the HE-500s ,a bit less transparent with that 7khz "boost"). I'm guessing that if high dynamic contrast , live perspective orchestral or other acoustic music is'nt your listening mainstay these phones may work just fine with the Burson Soloist. With what seemed liked vast amounts of unused gain available I thought that it was "highly" improbable that the BS would'nt have the sufficient amount of gain needed to drive HE-6 to where I wanted to regardless of that low 83.5 dB at 50ohm rating.
Initially, I had a slight scare with the Soloist switched to the medium gain setting, but after switch to the high gain setting I was able to find "useable"volume at about 12 o'clock (or so I thought, initially). After about an hour or so of play time it turned out that useable volume actually starts at about 9 o'clock. I now have much greater range of adjustment at hand & I'm absolutely positive my ears would give out before I run out of volume steps on the attenuator. The HE-6s are "cleaner" sounding & reach deeper in all parameters than the HE-500s, with sufficient amplification . I'm trying to figure out how you give the HE-500s an A+ rating & the HE-6s an A- rating the addition of facts don't support that result. Ratings of course are subjective, & normally not anything I put much importance to unless I personally know who did the rating.
