KingRex HQ-1 Headquarters headphone amp Review

(The above picture is how I would have like to have had the feet.  But on the review unit the feet were small and so the two face plates sat on top of each other and the top would slide off and behind the bottom.)

Using it

Setting up and using the KingRex HQ-1 is a snap.  There isn’t much more than to plug in the XLR power cable, the power cord, interconnects and your headphones.  The button in the middle switches between headphones and line out.  As stated above, there are a couple things to keep in mind.  200+ hours of pink noise burn in is a must to help smooth out the highs and increase bass response.  Using a better than supplied power cord is recommended to achieve a punchier, more filled out mids and lows and warmer sound.  There is only 1 line out, so using it for a pre-amp works if you only have one source.  My only complaint in the using it category is that the HQ-1 should remember which way you were using it last on a power cycle.  Turning off defaults it back to headphones mode each time.

While running the amp, sometimes for days on end, it never got hot or warm.

Also, giving the HQ-1 a half hour to hour long warm up time is recommended, especially when using in pre-amp mode.  Starting off cold can it can sound, well, frankly it sounds boring before warming up.

Sound

So here is where the needle hits the groove, or, err, is that one used too often?  Anyways,  I started off with a couple days of just listening to the HQ-1 at the office.  Out of the box and into the ears would not be a suggestible approach. It sounded harsh in the highs and very little bass and mids were not filled out.  I could only take an hour or so listening to it before I had to take the K701s off.  The HQ-1 shed the hardness in the highs after a couple hundred hours of pink noise burn-in, two hundred and sixteen to be precise. During what was otherwise known as the week of Thanksgiving. The amp developed a smoother, calmer high end and upper-mid range and the low end gained some volume.

The smoothing out of the high end was nice, but with the AKG K701 headphones, the amp just didn’t develop enough of a low end volume to balance out against the volume of the smooth high end frequencies.  Even with smoothed out and liquid highs, and with the slight gain in low end after break in, listening for long stints just wasn’t that enjoyable.  Now, don’t get me wrong. I wasn’t looking for a hip hop thump, I do use the K701 headphones after all. But after about an hour worth of listening I had to take the cans off and give my ears a rest.  Listening fatigue I figured, was being caused by a imbalance between the high end and low end, and a bit of a hollow middle.

Not ready to write the HQ-1 up as being this way, even though, I just did, dang!  Anyways, I really wanted to figure out if changing something, either the interconnects, source, or power cable, could make a difference. First I switch out the Granite Audio #470 power cables for the much cheaper, and bass heavier, Blue Jean Cable LC-1 Low Capacitance interconnects. They couldn’t balance out the sound, nor could the MircoPearl interconnects I had on hand either. The volume of the high frequencies was still too loud compared to the low end.  Smooth, but just too loud.

Next up was source. I played around with amp on many sources, ranging from my Dell desktop straight into the amp, which suffered the obvious issues of a poor source. Next to the Audio Note DAC One, which showed that the amplifier is fully capable of producing highly detailed sounds and a sweet smooth sound.  Too sweet though, still too sweet.  A Sony PS1, which the amp was able to show the high end and low end roll off reported in Art Dudley’s Stereophile review. Finally I plugged in my Rega P3/24 through a Moon LP3. Ah, I was onto something, something worth listening too, and more so, without significant listening fatigue.  But still the HQ-1 didn’t present a balanced low and high end, and mids were still a bit hollow to me.  So, spurred on by a recent demonstrations of some Nordost power cables at AudioVisionSF, I figured I needed to try a new power cord.

So I took the stock power cable out and replaced it with a Granite Audio #560 and serious magic was made. The low end came alive, detailed, and the mids thickened up. What a difference a power cord can do.  I was thrilled.

Now, I’m not going to argue the case for good power cords here, but I am going to say, that with the set up I had for testing the HQ-1, I didn’t feel I got the most out of the amp until I put a high end power cord on it.  A power cord costing about as much as the amp itself, but the difference was immediately apparent and I was able to listen to the amp for long stretches of time. In fact, I read the 6moons.com review of the HQ-1 and was in full agreement with the reviewer’s conclusions until I switched the power cord and now have come to different a conclusion.

Once this problem was solved I was able to focus in on other qualities of the amp.  Like soundstage, instrument separation, dynamics, and how it handled different musical styles of various complexities.

Soundstage of the HQ-1 is a bit tight.  No matter the music played, most of it felt right there next to my ears.  I was enveloped in a warm sound that left very little space for air or imaged any instruments stratospherically above others.   Not too often was there any sounds that really felt like it was coming from outside the K701s or my head.

In conjunction with this soundstage, instrument separation was also on the close side.   There was very little air between instruments.  They didn’t feel like they were on all on top of each other, nor did they feel compressed, just very close to your ears, as if in a small warm room carpeted room with lush dark cherry and sunset orange spread pillows and a bit of gray haze in the air.  Even between low and high volumes, everything was there, at equal volumes (pending power cord) and it all felt close.  I believe this could be do to, as KingRex says, the WIMA input capasitors which they used because of the “enhance[d] acoustic density”.  It sounds just like that.  Dense, close, warm.

Tied in with all this is the dynamics of the sound.  How much distance could sudden volume shifts cover? How fast could the amp switch between these sudden changes?  As well, how well did the amp portrait gradual swings and undulations in songs?  Well, you probably have an idea based on the ‘dense’ and ‘close’ description above.  It seemed to me, the amp didn’t shift that much, or undulate very noticeably.  Most things felt right there next to your ears, warming them and keeping that empty space in your cranial cavity humming away.

So how did the HQ-1 treat complex versus simple music.  I mean, full on orchestral or distorted industrial versus a girl and her guitar.  Results for this could vary based off of the cans you choose, but on the K701 headphones, complex music seemed to blur in the mid range.  Sometimes a bit too much gray haze. Instruments or noises lost some distinction between each other.    For more simplistic music, and I do actually mean anything other than some of the most demanding parts in complex pieces, the amp sounded great.  In fact, with the warm and close sound, and smoothed out highs, I found I really enjoyed hard rock and metal the most.  It helped to fill in what would typically be so much space in some of those haircut band recordings of the 80s dry and cold recordings.   Jazz is smooth and horns are never piercing.  Male and female vocals are very full bodied and lush, strings and pads are rich and satisfying.   The HQ-1 definitely imparts a sound on the music.  Smooth, warm and intimate. But without being spit upon.

Last but not least, the HQ-1 in pre-amp mode.  I really enjoyed the HQ-1 as a pre-amp, especially when the source was my turntable.   The smoothed out liquid highs reduced the volume, clarity and forwardness of the pops and clicks of some of my older vinyls.  Paired with the excitable Jeff Rowland 102 S, spinning vinyl was the highlight of my review period with the HQ-1.  The HQ-1 smoothed out some of the issues of an entry level hi-fi turntable and and the Jeff Rowland took the sound of the HQ-1 to new dynamic heights.  In fact, if the turntable was my only source, and the Jeff Rowland my amp, I would seriously consider the HQ-1 as a pre-amp for this combo.

Conclusion

To quickly summarize my verbose writings above, I would say the HQ-1 offers smooth and liquid highs, never being sharp or painful. But to get the most of it a good power cord is a must. Due to the smoothed out highs some dynamic range and punch is lost, but just slightly. Adding a good power cord will do a good job to correct the lack of punch.  It is very detailed after the power boost from a good power cable and the soundstage has a more confined soundstage.  The headroom, or high frequency bounce you get in a pair walled room is rolled off.  Instruments are defined but without sharp boarders and it wasn’t often I felt a sound was coming from too far outside my head. On some of the most complex parts of some music the amp did loose detail and instrument separation.

After a couple months with the HQ-1 I’ve come to really find it enjoyable.  It certainly isn’t going to win fans of the ‘pure’ hi-fi, but it will win fans with its warm sound, smooth highs, and intimacy.

If you have a chance to listen to one you shouldn’t pass it up. It offers a specific sound you might find attractive. But, if you hear it with a standard power cord, even the one supplied by KingRex, keep in mind the amp is being sold short.