My Rok Appreciation post.
or
An unconventional ‘review’ of The Rok.
I’ve had The Rok for several months now and the write-ups I’ve read have been written in the usual ‘review’ style of description of this amp.
Instead I wanted to describe how well it performs for me, what features and sonic attributes it ‘brings to the table’, but most importantly why I value it so highly.
And yeah it does have its share of idiosyncrasies, which in my mind anyways, fully qualifies it as a stratospheric Audiophool amp.
But, it needs to be said that all of these ‘nit-picks’ just utterly vanish, when I’m listening to The Rok.
So I’ll list specific relevant technical ‘features’ and then add some context for how they contribute to this amps prowess. Along with a short concatenation of how these features are interconnected in such a way to yield significant highly valued sonic traits.
#1 Micro-Processor Control
This bit of Hi-Techno-marvelous capability adds a good deal to the complexity of an otherwise fairly ‘simple’ design. The counterbalance to this added complexity is rock solid operation, long-term consistency, and a simplified and optimized signal path, from the inputs thru to the outputs. All the while keeping the necessary operational parameters optimized, and, at the same time protecting against deleterious “transient phenomena”…
#2 Unique Cyclotron Circuit
This is an intrinsically rather simple design, which tends to become rather complex in execution. And since the entire cyclotron circuit (along with the requisite power supplies) float, independent of ground, this adds to the complexity in bringing out the very best of this circuit topology. And since the signal path is significantly simplified, compared to other fully balanced designs, this helps reduce how much the signal is ‘altered’, i.e. it makes for a ‘shorter’, ‘simpler’, wire with gain.
#3 1% Matched Volume Control / Gain
This is possibly the single greatest feature of this amp in terms of SQ. This feature essentially means The Rok has matched channel gain, no matter where the volume control is cranked to. This is a big step up in terms of delivering both channels of information as close as possible to their original amplitude, no matter where the MOAR knob is. The most impressive result of having matched channel gain is in the bass, especially the deep bass.
#4 Very Low Output Impedance (0.03Ω)
This is VERY low output impedance. This technical prowess characterizes this amp’s ability to TIGHTLY control the excursion of the driver, no matter what. This mightily helps not only the extreme low frequency bass definition, but also tightens up the entire audio spectrum.
#5 2Hz Power Bandwidth
The Rok can deliver power down to 2Hz (-3dB down) which is deep into the subsonic range. This ability to deliver full power into the sub 10Hz range of audible frequencies means it is not anywhere near it’s design limits, nor capability, at ‘normal’ audible bass frequencies (20Hz and up).
#6 4 Watts/Channel of Class A Operation
Everybody knows class A operation is always best, and for the vast majority of headphones, we probably will never need moar power than this, with the exception of but a very few, exceedingly power hungry units. And with enough power available to drive 4Ω speakers with 100w/ch, The Rok has enough hutzpah for just about everybody using either headphones OR speakers in near-field use, regardless of what transducers you’re driving. Well unless you need to exceed ear-bleed levels.
#7 Completely DC Coupled
Without coupling caps nor servo’s, there is no gross phase shift nor ‘muddying’ of the power delivery as the music signal approaches DC. This really helps the bass as you might expect. And not just in terms of power but with the increased magnitude and resolution of the inner details everywhere, but especially in the low end.
And in the past, in my own crude way, I explored what acoustical improvements were achievable in terms of more closely matched channel gain, and The Rok is light years ahead in this one aspect alone.
The single most notable improvement is extension, control and the degree to which the bass is fully coupled, well into the subsonic region of perceptibility. But this ability affects more than just bass instruments. All instruments/voices gain an increased degree of palpable ‘realness’ as their inherent acoustic power also couples more closely to itself and to the acoustic space they audibly exist within. All because both channels are much closer to having identical gain.
And so when you combine The Rok’s power (ability to dump plenty-O-current), with it’s extremely low output impedance (0.03Ω), and a power bandwidth down to 2 Hz, along with having the Cyclotron circuit DC coupled, and matched gain, well, these design criteria techniques combine to insure that the bass is presented extremely well, with the capability of prodigious subsonic response. But this combination also ensures that the bass is highly resolving and tightly defined, which yields a degree of resolution of all the very low frequency information, which is somewhat of a rarity.
And all of this is monitored, managed, with potential fault modes of operation controlled by a custom programmed micro-controller. This ‘computer controlled’ amp is why it is DC coupled clear thru, why it has no servos nor coupling caps on the output, why it is as stable as it is, why it clicks when it changes modes of operation.
And with the Cyclotron’s simplicity in its audio path, especially the output section, while running with 4 watts of class A power, allows The Rok to operate in the most ideal way an audio amp can, for driving headphones.
And after reading all of this some might think I’m a heavy bass freq, and to a certain extent that is true, but not for the reasons you might think.
You see when the system is capable of delivering the musical signal with the least amount of alteration, especially in the bass all the way down into the sub-sonic region, everything changes.
And for the better.
What I’ve re-discovered is that after the system re-assembles the signal and it is acoustically re-aligned ‘properly’, all of the acoustical energy of the original voices/instruments are presented in their proper time and way, to our ears.
And when this happens everything ‘snaps’ into place.
All instruments/voices, all acoustical information is more closely coupled/bound with their original source(s) and as such the available power inherent in those acoustic sources is presented with a greater degree of the actual acoustical power of the original. This means that the acoustic power is more ‘effectively/efficiently’ coupled/bound, which makes the acoustic presentation more closely matched to their original sources. And when the available acoustic power is ‘properly’ coupled/bound, each instrument is experienced as being more ‘real’.
And the bass is the ‘key’.
And The Rok delivers this degree of control, power, definition, resolution not just in the bass, but throughout the audio spectrum.
But it doesn’t stop there, no, no.
Because when the bass and all of it’s resonant harmonics can more fully couple to their ‘parent’ acoustic source, I have found that the rest of the audible spectrum will also.
But it also means whatever low frequency acoustical information that any voice/instrument has, is now presented in a ‘proper’ way (coupled together) right along with the rest of that sources acoustical energy. Of course you’d expect percussive sounds to benefit from this ‘properly’ coupled presentation, but I’ve found that every voice/instrument does also.
And in ways that can be quite surprising, startling even.
The Rok can deliver this degree of precision, control, definition, resolution, over the entire audio spectrum, in spades.
And granted I’ve lightly modded my Rok with ‘better’ WAQy equipped fuses and it’s being fed by a dedicated branch circuit from my electrical panel, plus other tweaks (see my sig line equipment list). So what I’m describing is more of what The Rok is capable of (can you say scaleability?) by an end user who has learned how to make small seemingly insignificant changes that remove choke points which more fully allow the music to grab my complete attention,
and not let go.
Yeah, The Rok…
Is solid as a…
Is stable as a…
Delivers acoustic density like a…
Just like I like!
JJ
ps, it’s too bad vocal intonation is missing from text based ‘discussions’, since The Rok-(Bold) is meant semi-facetiously
think of a pro wrestling announcer when you read The Rok… hahahahahahahahahaha
