[r010159]

I have compared two amps with the 250-ohm Beyerdynamic DT880s, an ODAC/O2 and the Apogee Duet 2. I am getting results that are apparently not supported by objective measurements. I am finding the O2 to be a little bright and even what some people call 'thin' for my taste. The Duet does not have this quality with its sound. But there are other differences.

In one example, a guitar is forward and distinctive on the soundstage in relation to the saxophone with the O2. The Duet has the guitar much more in the background to the point of almost blending in with the other instruments in the background. In another example, the beginning of a song has heavy reverb which is also up front where there is a distinctive echo with the O2. The Duet has the effect of the reverb very subdued in comparison.

Could differences be accounted for by the synergy between the DT880s and the amps? For instance, the output impedance of the O2 is something like 3 ohms. The Duet is 30 ohms. Could this account for some of differences between the amps? I am already accounting for the brightness of the headphones through careful EQing. Also can this synergy (or lack thereof) be accounted for by other variables that are not easy to quantify? I thought a damping factor of 8 would be enough not to introduce a distorted frequency response. Maybe I need to get the 600-ohm versions of my headphones? I hope not. I do not have that kind of money.

EDIT: The bass and treble are subdued compared with the mid-frequencies. Besides the comparative brightness of the O2, the bass with the Duet is boomy and not controlled. This mid-frequency bloat can be caused by inadequate damping factor. Just a thought.

Bob

PS: Isn't this entertaining, my search for perfection?

 

[Hairspray]

I have compared two amps with the 250-ohm Beyerdynamic DT880s, an ODAC/O2 and the Apogee Duet 2. I am getting results that are apparently not supported by objective measurements. I am finding the O2 to be a little bright and even what some people call 'thin' for my taste. The Duet does not have this quality with its sound. But there are other differences.

In one example, a guitar is forward and distinctive on the soundstage in relation to the saxophone with the O2. The Duet has the guitar much more in the background to the point of almost blending in with the other instruments in the background. In another example, the beginning of a song has heavy reverb which is also up front where there is a distinctive echo with the O2. The Duet has the effect of the reverb very subdued in comparison.

Could differences be accounted for by the synergy between the DT880s and the amps? For instance, the output impedance of the O2 is something like 3 ohms. The Duet is 30 ohms. Could this account for some of differences between the amps? I am already accounting for the brightness of the headphones through careful EQing. Also can this synergy (or lack thereof) be accounted for by other variables that are not easy to quantify? I thought a damping factor of 8 would be enough not to introduce a distorted frequency response. Maybe I need to get the 600-ohm versions of my headphones? I hope not. I do not have that kind of money.

EDIT: The bass and treble are subdued compared with the mid-frequencies. Besides the comparative brightness of the O2, the bass with the Duet is boomy and not controlled. This mid-frequency bloat can be caused by inadequate damping factor. Just a thought.

Bob

PS: Isn't this entertaining, my search for perfection?

The 880 is very bright, not the O2
(btw, the output impedance of the O2 is less than 1 ohm)