I finally have some little time tonight to test the rock in my home system. The connection is same as my signature below, while the HA5000anv is replaced by the rock.
It seems lot of us are very interested how's the rock will perform when connect to IEM, so the test tonight will be concentrated on the performance of UE11pro pair with the rock.
As the rock only have one 6.3mm output, Audio-Technica AT501cs 6.3mm to 3.5mm adaptor are being used.
I originally expected it is the best setting when connect with UE11pro, unfortunately I was wrong.
Similar to some of the amplifier that I owned currently (HA5000anv) and previously (Luxman P-1u) which famous in driving low impedance headphone, all of them can not drive the UE11pro well.
The rock with low gain setting makes the UE11pro giving too much bass, tonal balance and clarity have been lost.
I can not hear any hiss at this setting, while it have a little channel imbalance in very low volume level, but become balance again when achieve normal listen volume
This setting gives better performance than the low gain setting. The bass are being well controlled, while tonal balance and clarity are back too. The sound stage is also much wider.
Unfortunately, hiss is more obviously at this setting. And channel imbalance is present in normal listen volume, imaging have a little shifted to the right although it is not obvious.
High Gain with 22ohm output impedance:
In according to the operation manual, when the bridge of the high/low gain selection is left out completely, the gain will be set to high and the output impedance increases from 4 to 22ohm.
I remember Corda Opera and Corda Symphony have similar function too~~. This setting gives similar sound with high gain only setting, however hiss will become disappear when music comes up and channel imbalance is solved too~~.
It is very surprised that the rock can drive the UE11pro so well with this setting and I personally prefer the rock over the HA500anv and P-1u with my UE11pro, of course it will be a different story when driving full-sized headphone