A member in Cali shared his review with me between the Niimbus and TT2, both driving his HE6, this was his response:
"Here are my impressions on the Hifiman HE-6 with only a working left channel. I used a few familiar test tracks of mine from my Questyle QP1R. I did the following, QP1R Line Out>Niimbus US4+ and QP1R Digital Out>Hugo TT 2. For the Niimbus, I was using the dac on the Questyle since it had no dac built in. The Hugo TT 2, the QP1R I was only sending a digital signal and using everything within the TT 2.
Niimbus had a wonderful amp section to power the HE-6, it drove it quite well. The amp on the Niimbus has the ability to increase the gain absurd amounts, so I set it to +12db of gain. Got great play on the volume knob and had a deep and punchy subbass.
Hugo TT 2 on the other hand had still a quite a beefy amplifier and excellent dac, far better than the Questyle I was feeding into the Niimbus. The midbass was a bit more present on the TT 2 in comparison. I was able to make out much more in the details of music on the TT 2 because of the dac section.
My take on the situation, the Niimbus is a bigger and stronger amp than the TT 2. The TT 2 isn’t a slouch when it came to amp especially with the HE-6 but the Dac really stood out like it often does when it comes to Chord products."