Pros: Sheer Sound Quality, Immense Output Power, Excellent Features, Amazing Synergy with HD800 & K812
Cons: Inbuilt DAC
Me: I am an amateur musician & avid admirer of music from India. I would like to call myself a music enthusiast, rather than an audiophile. I was inspired by music since childhood, and as the time passed, the passion of music grew in me, and that subsequently led me to join Head-Fi. Eventually, I found the pleasure of listening to music mainly by the HD600 and recently, by the seductive LCD2 headphones, and realized the true components of recorded music. I usually like to listen to Indian Classical Music along with Bollywood songs. My main listening genres include classical, vocal, instrumental, jazz and sometimes pop. With time, my sonic preferences have very much grown. I avidly admire transparency, accuracy along with neutrality, I mostly listen to full sized open back headphones and my all-time favorite headphones are Sennheiser HD800 & AKG K812, which I run from solid state amplifiers. I prefer & admire transparent solid state headphone amplifiers simply because they provide best possible accuracy, transparency & reliability.
I am an average consumer & a humble enthusiast, I like to pen down my thoughts, & I love to express my feelings. I do not receive for any sort financial benefits through this review. My articles are a purely honest writeup aimed for fellow enthusiasts here at Head-Fi community. My profound thanks to Matrix Audio for arranging a sample unit of HPA-3 for my evaluation.
Intro: Matrix Electronic Technology Co. Ltd., located in Xi'an Economic and Technological Development Zone, in the ancient city of Xian. Matrix is an enterprise that dedicates to development & manufacturing of high-fidelity audio products. It also collaborates with a number of domestic and foreign companies on OEM and ODM business. Matrix has its own highly qualified R&D team, which designs all of their products.
I assume we all heard of matrix only since its release of M-Stage headphone amplifer around 2010 which stirred the headphone amp market & was extremely well received across the world; hence It became a benchmark device. Im a proud owner of Matrix’s HPA-1 & HPA-2, over more than two years. I loved them a lot, had a wonderful time with both of them. The M-Stage is getting updates in circuit board every two years. The latest model is HPA-3, improvised on previous designs.
HPA-1 was warmest & ‘richest’ sounding of all three, but had mediocre inbuilt DAC, plus slightly audible noise floor. It had the original BCL style gain switches. HPA-2 largely improvised from HPA-1, applied better performing 24/192 DAC with fixed +15dB gain. Also, the benchmark bass ‘bump’ has vastly reduced, with much better cleaner & flatter output.
Their latest release is HPA-3, successor to HPA-2. The HPA-3 has two variants, HPA-3U a Single end headphone amplifier with inbuilt DAC, whereas the HPA-3B, truly balanced headphone amplifier without inbuilt DAC.
Technical specifications of HPA-3U:
SNR: ＞-112dB at 20Hz-22kHz A-Weighting
THD+N: ＜0.0003% at 1kHz 1VRMS A-Weighting
Frequency Response: 20Hz-20kHz(+0.01dB/-0.04dB)
Output Impedance: 51ohms
SNR: ＞-112dB A-Weighting
THD+N: ＜0.0003% at 33ohms 90mW 1kHz A-Weighting
Frequency Response: 20Hz-20kHz(+0.01dB/-0.04dB)
Output Impedance: 0.2ohms
Output Power: 2800mW at 33ohms / 420mW at 300ohms / 210mW at 600ohms at THD+N=0.01%
Gain: 5dB 10dB 20dB
USB Chip: XMOS U-Series Asynchronous USB Chip
D/A Chip: Texas Instruments DSD1793
SNR: ＞-110dB A-Weighting
THD+N: ＜0.002% at 1kHz A-Weighting
PCM Sample Rate: 16-24Bit /44.1kHz 48kHz 88.2kHz 96kHz 176.4kHz 192kHz
DSD Sample Rate: DSD64（DoP）
Windows XP/Vista/7/8/8.1 systems need to install the driver supplied
Mac OS X 10.6.4 and above version have native support and do not require a driver
Can be used with the most of Android devices via the OTG cable
Can be used with iOS devices via the Lightning to USB Camera Adapter
Supports both 110V & 230V (switchable)
Power Consumption: ＜25W
Fuse: AC250V/500mA 5×20mm
Weight: 1.7 KG
Packaging & Accessories: The HPA-3U comes packed in Matrix Audio’s strong cardboard box with foam protection inside & necessary accessories included in the package.
User manual & Driver CD: Contains instruction about operating TRD3+ & some warranty information. A compact disk containing HPA-3’s USB driver is included.
USB Cable: Good quality USB A-B cable. About a metre and half long.
Power Cable: AC power cord to attach to mains supply.
Design and Build: The HPA-3U a marvelous & Robust build quality with perfect finishing. The case is redesigned from past to be more efficient. More vents, thicker case, excellent finished edges & a modern look. It is made up of aluminium, and is painted in matt black & brush finished. Overall the amp feels heavy in hand and comparatively longer is dimensions than other amps in size. On the front side, we have Volume control knob, headphone jack is present in 6.5mm format along with a gain & input switch. On the rear side, we have Power socket cum switch, USB input port, along with a RCA input/output jack. Power button is very rugged & tough; Volume knob operates in a very smooth fashion & is very steady. Headphone socket is ball bearing type & goes easy on the headphone jack, does not cause scratches on the surface.
Special mention here is: HPA-3 is capable of handling both 110/220V, whose selection switch is on side of the amp. Plus the AC fuse is accessible right besides it. To remove the case & access the circuitry, one has to remove top four screws using allen keys Size (2 & 2.5) plus additional two side screws on each side, to remove the top cover. One small issue user might face here is: Vents on top cover can attract dust or incase a few water droplets fall down, it will straight on the circuit board & damage the board.
Considering the Internal components, HPA-3U has an entirely redesigned circuit board with has double sided PCB with no manual wirings except the toroidal transformer joints. Components are placed in a symmetrical & neat fashion. All components used are carefully selected; including all dale resistors, Alps-27 blue velvet pot, premium caps. For D/A conversion, the HPA-3 employs DSD1793 (which is DSD capable version of PCM1793) for USB transfer, asynchronous 24 Bits/192 KHZ capable Xmos Chip. There are no user replaceable/serviceable parts inside theHPA-3U, except the op-amp scoket. Board is excellently soldered and has a reliable workmanship. TheHPA-3U generally runs warm by temperature due to being Class-A. It can also act as standalone headphone amplifier when fed with RCA inputs.
Sound: The HPA-3U offers a very flat, detailed & accurate, sound sonic presentation. Sound-stage width is superb & expansive. Overall puts up an amazing performance. Lows are tight, accurate & go deep with good impact, The ‘bump’ associated with older HPA’s is mostly gone. Mids sound very clear & open. Highs are very clean, airy, very detailed & extended. Overall no presence of any significant colouration.
I expected that matrix would develop and include a 32 bit DAC in their HPA-3U. The M-Stage have always been a strong & reliable amp, but contained a mediocre DAC. Though DAC in HPA-3U is good, but is not performing upto the standards of the amazing amp circuit. Soundstage in HPA-3U is just great . It has a fully circular 3D imaging. Detail retrieval, and dynamics are excellent, perhaps one of the best for an Amp/Dac under the price tag. Overall the sonic presentation is high level of transparency and accuracy. Absolutely zero audible hiss/noise, and zero EMI pickup. Alps RK-27 pot does an amazing job of controlling volume very precisely without any channel imbalance & noise with retaining maximum sound quality. Another plus point here is, the HPA-3 has relay mechanism which prevent any noise pop’s when headphones are plugged in. This way, a better safety is guaranteed for the precious headphones.
Op-Amp: Stock op-amp is LME49860 from Texas Instruments, which does its job. To test if the HPA-3 scales with better op-amps, I tested it with many op-amps, and settled on LME49710HA X2 with browndog adapter. The HPA-3U indeed does scales well and supports the replacement op-amp.
With LME49710HA, I have about 10% improvement from stock ones, with increased soundstage depth, excellent detailing & instrument separation & even more extension in treble. Overall increase in clarity & transparency. For HPA-3U, ASIO suits better than other pluggins. Ofcourse it is audibly better than the default DS. In Matrix control panel, Set Transfer as “Most Safest” This again ensures maximum possible performance.
Driving Power: The HPA-3U is very powerful when it comes to driving headphones @2.8W power in tap. Drove my AKG K702 (which is a demanding headphone when it comes to ampling) well with 25% volume pot utilized in least gain of 5dB. Infact, I couldn’t even switch over to 10dB gain switch, because the HPA-3U is so powerful, 5dB gain is more than enough to drive any headphones. I also tried my trusty LCD-2’s, U200 drove them very well, with good synergy. Both AKG K812 & HD800 sound fantastic HPA-3U. It anything drives from IEM’s to planar magnetic with ease. Volume pot does a very good job here, volume increase very steady and in a highly accurate fashion. No channel imbalance. Overall, the HPA-3U impressed me a lot in the sound regard.
Comparison: A very good competitor for HPA-3U we have here is Yulong Audio’s U200 whose review I wrote a while ago http://www.head-fi.org/products/yulong-audio-u200-dsd-32bit-384khz-dac-headphone-amplifier/reviews/13333 which is also similarly priced & has similar functions. Now we have a tough competition, both newly released amp/dac’s, are priced around very well & both perform really well.
The HPA-3U has user-changeable gain 5/10/20X settings, & 230V/110V AC voltage switch to use in various parts of world without any hassle. It also has an internally swappable op-amp for any such rolling. Another advantage the HPA posses over U200 is that the HPA-3U has Alps blue velvet pot, which is simply well ahead of Alps-16 used in the U200. The U200 offers WiFi module for an additional 100$, which I sometimes feel not very necessary. The Yulong U200’s gain is fixed, but it drives all earphones & headphones well. AC voltage switch is not present, and can be a drawback for frequent international travellers. The HPA-3U also has mute relay mechanism, which is a plus for headphones safety.
In terms of build quality & workmanship, the U200 clearly has an upper hand with superior build inside & out, HPA-3U follows very closely, with slightly inferior part quality & design in few areas. The U200 has a very neutral & expansive sound quality with a touch of naturalness: sweet mids, slightly smooth highs & full bodied bass. Soundstage is deeper & more expansive in U200. HPA-3U has stronger bass clear & open mids along with extended, & revealing highs, and not exactly ‘natural’ if I must say. I would rather call HPA-3U more analytic & clinical that the U200, but only with a slight margin. HPA-3 has about 15% lesser soundstage than U200, but has extended & more detailed top end. Mids are neutral compared to addictive smooth mids of U200. HPA-3U lacks soundstage perhaps due to lower 24/192 DAC capability. Audibly, The HPA-3 lacks the vast, airy & relaxed soundstage of U200, along with silky smooth mids. Top end is relaxed & airy in U200. The U200’s DAC is very superior & well performing, & has a fairly good amp section. The HPA-3U is just the opposite: superior amp section & fairly performing DAC unit.
In end of the day, both HPA-3U and U200 have an excellent performance & high value aspect associated with the price paid. Here the decision makes up of preferences only & sound quality almost same on both the devices. But HPA-3U has upper hand when it comes to flexibility & features.
Conclusion: The HPA-3U continues the legacy & Reputation of M-Stage series forward.
The Matrix M-Stage HPA-3 is a benchmark & legendary headphone amplifier. It is not just another amp, it has legacy behind it. It impressed me not just in sound presentation, but I literally loved every inch of it. The HPA-3U excels in each and every criterion you put through it. Its workmanship is of high standards, and thus very reliable & robust in operation. The HPA-3U is reputed to have very good synergy & pairing with world famous high end headphones like HD800 & K812. I highly speak & recommend of the HPA-3U. It is a MUST HAVE device for HD800 & K812 headphones, & the pair performs amazingly good with perfect synergy. Perhaps HPA-3U is the best solution for these headphones even at double the price.
1) Design and Build: The HPA-3U has a very well designed and implemented build. Both internal & external build quality is supreme excellent workmanship.
2) Sound quality: The sonic presentation here is very neutral & accurate & transparent, with minimum or none colouration. Sonically, performs extremely well. Powerful enough to drive any dynamic or even planar magnetic headphones.
3) Features: The HPA-3 has perfect set of features which are needed in a headphone amplifier device. Voltage switch, Alps Blue velvet, mute relays, op-amp rolling together makes it a perfect device.
Cons: Inbuilt DAC: This has got be the only drawback for the HPA-3U. The inbuilt DAC is very good, but not in the long run. Audibly, I observed the inbuilt DAC is limiting the performance (particularly soundstage) of amp section. I sincerely hoped, with HPA-3U, Matrix would bring a better performing 32 Bit capable DAC. This is the only area where I am disappointed with the HPA-3U.