After my review of the iDSD Micro Black Label, I was offered iFi's newest and only offering in their "Pro" line-up. I've had it for the past four days, and am slowly gathering my thoughts; just like the iDSD, this thing is feature packed, almost beyond belief.
My full review in the coming weeks will be much more fleshed out than this impression, and I preemptively apologize for any details missed now, as there are quite a few to cover.
Let's start with inputs. Three pairs of RCAs and a pair of differential XLRs, all controlled by the left-most knob on the front. Outputs consist of a pair of RCA outs and differential XLR outs, on the back. On the front, there is a pair of 3-pin XLR outs meant for use with headphones that utilize, well, two 3-pin XLRs. These also function as two 1/4" TRS auxiliary plugs, each intelligently outputting stereo. They can be used simultaneously, to my knowledge. There is also a 4-pin XLR out on the front, as well as a single-ended (TRS) and balanced (TRRS) 1/8" auxiliary plug.
Also featured on the front are two knobs, each controlling an adjustable XBass+ and 3D Holographic Sound, respectively. Unlike the iDSD Micro Black Label, these each feature four settings, from off to the highest level of their respective effects. I'll go into more detail on these in the full review. There is also a power button and a gain slider (+0 dB, +9 dB, and +18 dB). Finally, there is the slider that controls the highlight of this product - the tube slider. It switches from solid state, to tube, to what they call "Tube+", which is a mode that reduces overall loop-gain and thus reduces negative feedback to a minimum. This results in a greater amount of the tubes' natural harmonics coming through, with even ordered harmonics being dominant. The tubes included are a set of NOS GE5670s.
I'd like to momentarily highlight how powerful this amp is. It can push 14W per channel into a 16 Ω load at full tilt, highest gain stage. There isn't a headphone on planet Earth that this cannot provide more than enough power for, barring electrostatics. iFi has included a plug on the back, which connects to a coming module that will allow users to power electrostats, so eventually those will be included. From the HE-6 to the absurdly low sensitivity and high impedance vintage AKG 240, this can provide headroom over anything, in terms of power.
Now after all that introduction, let's move to sound. While not as sterile-clean as my HP-1, it certainly is no let-down in solid state mode. In fact, it performs wonderfully. It adds little to no coloration to the signal, as I believe that a solid state should. With THD+N at less than .0015% running balanced in solid state mode, it sure is low. Moving to the "Tube" mode, the sound becomes noticeably warmer, with second order harmonics dominating mainly, and bass becoming a little more syrupy compared to solid state. The second order harmonic emphasis, with my limited listening thus far, adds a certain musicality to some recordings, which I am having trouble quantifying further. I will continue to listyen critically as the review period continues, and have faith that in my full review, I will be able to better and more accurately comment on exactly what it is that I'm hearing. The "Tube+" mode, as advertised, seems to emphasize further these changes, particularly that of the harmonic emphasis.
As a final note, I think one of the highest luxuries in a headphone amp is using an IR blaster remote and watching the volume knob physically move. It's incredibly satisfying to lounge back 8 feet from my desk and volume match a questionably leveled album from afar.
This product was provided to me for review by iFi. I am not being paid by anyone to write this review, to endorse the product reviewed, or for the content that I put in the review.