Page 4 Phantasy Compatibility, Sound, Conclusion

High Impedance Fiend

SET headphone amplifiers never tend to be the most powerful of designs in terms of pure wattage per channel. While Sassy’s hybrid nature puts a lot more power into low impedance loads than it does high impedance, this is the other way around, with 250mW into 300ohms and only 200mW into 60! Phatlabs actually call 60 ohms plus the recommendation as well and have integrated an impedance switch for versatility. It has two options, hi-Z (150 ohms plus) and low-Z (150 ohms and under) which I think Eric Lin of PHATlabs is much more qualified to explain than me.

“With output transformers, the Phantasy has to switch the secondary windings to be paralleled or serial depending on whether the connected headphones need high voltage (high impedance like HD800 or T1) or more current (low impedance like Grado or AKG). When impedance is matched, the frequency response is accurate and flat beyond audible range. However, unlike Sassy’s almost unlimited output, the real limitation on Phantasy driving capability is its secondary windings resistance that is in series with headphones and consumes power too.”

I however thought there was more to it, probably a change in the output impedance between switches. Eric confirmed that the hi-Z switch has 4x the output impedance meaning it might not be that great for hi-Z cans after all. I say that because with my 300 ohms HD800s, which should be suited to work with the hi-z setting I am getting a completely skewed frequency response and a sound uncharacteristic for both Phantasy and the cans. Now because the impedance plot of the HD800s is all over the place a high output Z will obviously have obvious changes to a headphone frequency response, just like the mega ohm of the current mode output of Bakoon HPA-01M did. With the lower impedance output the HD800 sounds absolutely marvelous, make no mistake about that.


Obviously I had to try outside the recommended settings a bit more and tried the 32 ohms Dharma which combines both electrostatic and dynamic driver technologies and can confidently say this was an ‘off’ combination. Even though the background was silent, one of the harder things to pull off with this can, the sound just didn’t sound too natural. Also under the recommended ohm allowance are my 50ohm planar magnetic ZMF Headphones Blackwood but these sounded much better, dare I say it, very good in fact. The ZMFs will also get on fine with both settings having a flat impedance plot unlike dynamic cans. Regardless nothing gets on with this amp like my HD580 and HD800, that really does seem where the Phantasy’s priorities lay.


Like a Mill Pond

It is clear from first listen that Phantasy is its own thing and unlike any other amp I have spent time listening to! While reading their information on the amp they like to throw out warm a lot but warm this is not. Instead its energy is sourced from the top of the mids and burns through into the treble, giving this amp a sense of clarity and clearness that is just hair raising. It has an ability to make some of the most confident amps sound a little muffled (small exaggeration but you get the gist). In utter honesty the only area I feel that give even the slightest hint of tube usage would be the timbre this amp helps produce, that has just some of the most organic textures to it.

Even more breathtaking is the structure of the sound. On such a quiet background the sound is so grainless that I am no longer listening to a speaker reproduction. It’s frightening really how little distortion or confusion there is to the sound, its like an untouched mill pond.

While airy from that helping of excitement in the top end, this is a pretty neutral amp and one that is snappy and fast. No mellowing or extra decay throughout the spectrum and nothing to really talk about in terms of particular frequency ranges. Bass is as you want it, extension when possible and noble punches. The midrange is raw and transparent… enough said. Treble is without doubt a little, dare I say it, bright. Not with a single negative caveat, I mean I absolutely love this amp with my HD800s. It isn’t sharp, brittle or fatiguing!

Now I have talked about just how clear the sound is and of course that helps when we come to talk about how I perceive soundstage. Instruments are separated at the highest level with plenty of space between structure of the music. The imaging is also what I believe to be accurate and composed. For sheer size width is just top level when running a spacious headphone i.e. the HD800.

Talking about the HD800 and using this in lo-Z mode gives me the sound that I have come to familiarise with this amp. But crazily when I do switch to high-Z mode allowing more voltage to flow to the headphones the sound changes massively and this switch will allow you to do your own experiments with the sound. As well as lowering the volume a bit we get all sorts of sound differences, namely a complete frequency response shift. Treble is lowered and bass is now thicker and warmer. For the most part the sound is a lot more muddy though with extra helping of decay and while there are some new positives to the sound, overall it is no where near as accurate, even if it is perhaps a more tubey sound.



It seems like between the Sassy and Phantasy you have two very different products. Sassy is easily recommendable, the safer sound signature, the more versatile in its output and also the one that can be considered truly portable. Phantasy is much more picky. Firstly you have to want to transportability, not pure portability. If you do just plan on dropping this down on your desk and never moving it, then you have a lot more options to consider in terms of desktop amplification. You then need to consider what you plan on pairing this with, high impedance dynamic cans seem to be its forte while planars are suitable but not as glorious, probably due to them craving juice.

Finally there is the sound, which while technically stunning, is quite distinct and won’t be the desire of all people. It certainly is not as safe as Sassy and these are all things to consider. The bottom line though, paired with my HiSoundAudio S6 and my HD580s/HD800s, I am sitting in the garden by the pool, hearing sound that is just sensational and for that I am so glad that PHATlabs have made the effort to put their knowledge to the portable audio realm!

Sonny Trigg
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