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Srajan Ebaen
Financial Interests: click here
Source: Raysonic CD228 [on review]
Preamp/processor: Meier Audio Corda StageDAC [on review]
Headphone outputs: Yamamoto HA-02, Woo Audio Model 5, Trafomatic Audio Experience Head One [on review]
Headphones: Audio-Technica AHT-W1000, BeyerDynamic DT880, Sennheiser HD800, AKG K1000 w. Stefan AudioArt harness
Cables: ASI Liveline loom
Powerline conditioning: Walker Audio Velocitor S
Rack: Acoustic System Int. HeartSong
Review Component Retail: $890

Not tongue-tied but christened tongue in cheek, the Headquarters HQ-1 by KingRex invites plays on words - giving no quarter, perhaps even quartering competitors' heads.

But literally, it just wants to be your headquarters for a headphone-based or mini hifi system. Prior reviews in these pages have extensively chronicled this Taiwanese high-value company. They made a name with very affordable Tripath amps and USB DACs.

For KingRex, this new headphone amplifier* with pre-outs positions itself higher on price. It suggests more serious ambitions. The clever name meanwhile creates parallels to the just as cleverly named PREference preamp sibling with top-mounted phono adjustments and outboard PSU. Is KingRex moving upmarket now?


* As the photos show, the HQ-1 is available with black or red face plates yet the bevel detailing of the red version does not carry over to the black which continues the look KingRex has championed in the past.

The company's Christine Wu confirmed the new trend: "Our latest product is a high-end 50wpc Tripath stereo amplifier, with higher power monos in the wings. The QS-01 power amp was announced in early September. I believe many people will be shocked by our new products. They were originally scheduled for roll-out by June but we postponed the launch schedule to tune them for even better sound. We will not only enter the PC audio sector in earnest but also progress deeper into the High-End sector. Right now there is plenty of cheap audio gear on the market but not all of it has high C/P. KingRex began to redress that balance with all of our initial offerings.
"You are correct to note that our prices now are higher but the truth is that we also exponentially increased our costs for material, design, labor and circuit originality. We really spend lots of money on quality parts and the pricing for our more ambitious machines now reflects that. Still, we are quite certain that when users get their KingRex components, they will find the cost to be disproportionately low relative to their satisfaction and our component quality."

Let's look at the HQ-1's nuts and bolts. Obviously, this newcomer is a two-box affair of equal half-width foot prints. It allows convenient stacking or going cheek to cheek on a standard audio rack shelf. The circuit is classic class A with Mosfet outputs—Toshiba A970/C2240 transistor for first stage, Hitachi 2SK214 current buffer—meaning it must dissipate at least twice its rated output at idle.

Because headphone voltages operate in the micro-watt range—though preamp duties could raise output voltages beyond can jams—power consumption remains below 10 watts. That's low-light-bulb green in the energy consumption stakes. In 24/7 practice, the amp gets mildly warm to the touch while its glossy cover and sides telegraph skin oils like the sanitation police to best limit fondling to the volume knob. To mount the pointy footers with adjustable tips merely requires peeling off the rubber bumpers to unveil the receiving threads. Being sized identically to the spike protectors, you can recycle the rubber slivers and tack them to the metal discs. It'll undermine your ability to slide the components atop a glass surface.

The power supply is of the linear kind and runs off a 48VA toroid, with five 2.200uF caps filtering incoming AC, three 4.700uF units smoothing outgoing DC. Eight "hifi-grade Nippon Chemicon electrolytics" create a total power supply capacitance of 25.100uF. Naturally, output power varies with headphone impedance so we get 100mW at 300 ohms, 170mw at 150 ohms, 360mW at 60 ohms and 570mW at 30 ohms. At 2Vrms output, THD+N is 0.005%. Dynamic range is 110dB, channel separation >92dB at 1kHz and >76dB at 10kHz and S/N ratio 115dB. [Clicking on the frequency response chart supplied by KingRex will download a 5-page PDF with laboratory results for the HQ-1.]

Downloads PDF

Circuit gain is 18.5dB, making it a standard medium gain one-source preamplifier if so used. I/o impedances are 15K and 1.8 ohm respectively, frequency response is 20Hz (-0.7dB) to 80kHz (+0.1dB). AC line tolerance is ±10% at the respective 110 or 220 international voltages. Dimension are 183 x 145 x 55mm for each unit and dress code is a black body with black or red fascia. Headphones used during R&D were Sennheiser HD600s, Audio-Technica ATH-AD700s, AKG 501s and Goldring DR150s. "Basically we tuned the sound with the HD600s as we think them very neutral and balanced. We tried many different impedance headphones to assure the amp performed well regardless of load."

The existing PSU upgrade for the T20 amplifier shown shares the resistor circuit with the Headquarters' power supply but the former's 13V/3A output spec has become 18V/1.25A for the HQ-1. "The biggest diffence is the transformer winding method but the PSU resistor circuit remains very silimar. We've had it in the field for a long time and with much excellent feedback and felt it was good and proven to be appropriate for the headphone amp. So we retained that part of the design."

It's been said often enough to be boring but needs to be said many more times: The most cost-effective way to arrive at bona fide high-end sound is to remove its greatest hurdle. That would be your room with all its deleterious acoustic interactions.

Enter headphones. Just make accommodations for a different kind of soundstaging and in-the-ear versus body-slam bass. Particularly with sealed headphones, you can listen when you want how loud you want without worries of upsetting neighborly or domestic peace. And room interactions are a thing of the past to make for far more predictable, repeatable and transferable performance.

Dollar for dollar, it is impossible—impossible!—to replicate headphone fidelity with regular loudspeakers. If funds are tight but ambitions high, get a superior headphone system. In 'once known, you can't unknow' fashion, it will also raise your standards. When the time comes to buy speakers, it will eliminate certain mistakes. You'll already know high-resolution low-distortion sound to not settle for less - which is harder to accomplish with loudspeakers.

Mr. Johnson Chou, president of KingRex

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