The Impressive Matrix M-Stage HPA-3B Balanced Headphone Amplifier

The M-Stage HPA-3B Balanced Headphone Amplifier

Who doesn’t love a great bargain? I certainly am a person who really enjoys finding things that perform well beyond their price point and when I had the opportunity to try out Matrix Audio’s new M-Stage HPA-3B fully balanced headphone amplifier, I leapt at the opportunity. First off, the photos on the internet showed an extremely handsome unit with casework that was well above the $419 price tag. Throw in the fully balanced front-to-back design; I was quite intrigued with the value proposition of the HPA-3B. The amplifier arrived several weeks ago and I still remember the complete surprise when I first pulled it out of the box. This was not a $419 product? It couldn’t be? I’ve seen units priced more than 2X with this type of solid construction and close attention to details. Instead, it reminded me of products that were north of $800+. The solid chassis is impressive and the overall aesthetics and heft of the amplifier will have your friends thinking that you spent much more on it than you really did. The volume knob; while a bit different looking, has a smoothness to it that really gives you a great feel and full control of the listening levels of your music. So was I impressed with the build quality? In one word: absolutely!

The M-Stage HPA-3B is a new member to the M-Stage series of headphone amplifiers. But this amplifier is the first of the M-Stage series that is fully balanced. However, if you have headphones that you can’t re-cable, no need to worry as the HPA-3B also has a standard un-balanced headphone option too. As well, if your source is single-ended, the HPA-3B does include two 4 pin XLR to RCA adapters to help you setup your system with minimal worries. However, I would recommend you look at the HPA-3U if you don’t plan on using this amplifier in balanced mode. During my listening sessions with this amplifier, I used it with both single-ended and balanced inputs out of my main DAC (Metrum Acoustics Hex DAC) and with headphones both in balanced and un-balanced mode. More to come on the results later…

The specifications are very impressive for such a well-priced headphone amplifier. The distortion (THD+N) is less than 0.0003% with an SNR up to -114dB. As well, there are three gain settings (5dB/10dB/20dB) to help you adjust the amplifier’s volume level to your headphones (regardless of how difficult or easy they are to drive). The design utilizes a fully symmetric circuit layout and a fully differential signal path in the amplification of the signal. Here are the specifications of the amplifier in both balanced and un-balanced modes:

Balanced Headphone Output
• Frequency Response: 20Hz – 20kHz (+0dB/-0.05dB)
• SNR: -114dB A-Weighting
• Distortion: 0.0003% at 300Ω 135mW 1kHz A-Weighting
• Output Power: 3800mW/33Ω, 1500mW/300Ω, 800mW/600Ω at THD+N=0.01%
• Output Impedance: 0.6Ω

Unbalanced Headphone Output
• Frequency Response: 20Hz – 20kHz (+0.03dB/-0.1dB)
• SNR: -108dB A-Weighting
• Distortion: 0.0004% at 300Ω 325mW 1kHz A-Weighting
• Output Power: 2100mW/33Ω, 430mW/300Ω, 220mW/600Ω at THD+N=0.01%
• Output Impedance: 0.4Ω

As you can see, plenty of power (especially in balanced mode) for pretty much all headphones I can think of that are not named the (now out of production) Hifiman HE-6s. Simply put you can drive pretty much any headphone or inner-ear monitor (IEM) out there with this one unit…and have plenty of power to spare for those harder to drive headphones. The extremely low output impedance as well makes this a very versatile amplifier; from sensitive inner-ear monitors, right up to power hungry full sized orthodyanmic headphones.

My Setup:iMac or CD Transport > Metrum Acoustics Hex DAC > (balanced input) M-Stage HPA-3B > (balanced output) Audeze LCD-X / Sennheiser HD800 / Hifiman HE1000

As well, I tried using the unbalanced output option with this amplifier and thus paired it with my Grado PS1000e headphones. But for the most part, my listening was confined to a fully balanced configuration.

I have often used Jazz at the Pawnshop to put a piece of gear through its paces, but I decided to change things up a little bit and instead I used Jazz at the Pawnshop 2. I know, not a huge departure from the original, but this is an equally outstanding recording that I’ve come to really know and love through the years. Right off the bat, the HPA-3B had a firm grasp of the Hifiman HE1000’s drivers. I never felt that things got out of focus or control with this amplifier. These headphones respond to more power in my experiences and running them balanced out of the HPA-3B yielded outstanding results with plenty of head-room to spare.

The ability of the HPA-3B to control the HE1000’s drivers was immediately apparent when I first started this recording. I was astounded that a headphone amplifier in the sub $500 category could perform so admirably with headphones that are harder to drive than most. My Resonessence Labs Concero HP does a great job with most of my headphones, but not the HE1000s. It really doesn’t have the potential to fully drive them to even moderately loud levels and what is played is too polite and laid back; to a point where the HE1000s aren’t anywhere as enjoyable as they are with my HeadAmp GS-X Mk2 (but that’s 5+ Watts into 32 ohms and a $3000 price tag; so maybe not the fairest comparison).

But thankfully the HPA-3B is up to the task and has power in reserve with these headphones. The presentation is a slightly warm and slightly tubey sound that never comes off as bright, or strident. I would classify this amplifier as slightly laid back, but still with plenty of punch when the recording calls for it. Something my Concero HP could never get fully. The players are well portrayed in that sound stage; though A-B testing with my $3000 HeadAmp GS-X Mk2, the HE1000s reach as close to their full potential as I’ve heard. The HPA-3B is a bit closed in sounding and not as full of life and energy. But there’s more than a $2500 difference between both amplifiers; so while not a giant killer, what the HPA-3B yields is an incredibly clean and lifelike performance at almost 15% of the cost. Now how’s that for impressive!

Next up was Tool’s 10 000 Days with my LCD-X headphones. I love this album to test an amplifier’s ability to deliver the visceral feel that this recording can offer. And here the HPA-3B continued to impress me. I had to keep reminding myself that this amplifier is only $420 as it performed well (and I mean well) above its price point. The LCD-X’s have never sounded better. The bass notes hit hard and landed quickly, then moved on with very little lingering (just as it should). If you’re on a budget and you’re looking for a headphone amplifier for your Audeze LCD-2, LCD-3, or LCD-X, I can think of no other that offers this type of performance to price ratio that what I’ve heard with this M-Stage amplifier. I usually reserve this type of performance for products in the $750+ range and to hear control, drive and transparency in a product priced at $420 has me re-thinking what I should come to expect from my audio gear.

Next up where my “picky” Sennheiser HD800s. While not the most difficult to drive in terms of power requirements, I have found over the past 5+ years, getting them to sound their best can be quite the challenge. I’ve found this particularly difficult with more “entry level” amplifiers, DACs and sources. This is what I found truly surprising when I first powered up my HD800s with the HPA-3B. In balanced mode, the HD800s came alive to a level that I’ve only attained with much more expensive amplifiers (typically over $750). The warmth of the HPA-3B really shined with the sometimes brighter than neutral HD800s (to my ears anyway) with incredible bass performance, outstanding vocals and treble that never had me winching with any hint of stridency.

Modern Cool by Patricia Barber can with the wrong setup, leave me a bit cool to the recording as Ms. Barber’s voice can come off a bit overly-stated; especially on her higher notes with the HD800s. Thankfully, the M-Stage HPA-3B came through with flying colours! Patricia’s voice was spot on and never “shouty”. The HPA-3B was able to capture the realism of the recording as it was a live event and the detail retrieval was definitely more than what I’ve come to expect from such affordably priced amplifiers. Sure I could hear a wider sound stage and clearer inner details from the recording with my HeadAmp GS-X Mk2 headphone amplifier, but now we’re talking orders of magnitude in terms of price with almost a 10X cost difference. The HPA-3B shows that you don’t need to drop a bundle to get fabulous sound quality from the venerable Sennheiser HD800s.

With a top notch and extremely solid build quality and great performance and sonic clarity (notice all the “ands” in this sentence), the M-Stage HPA-3B gives you an incredible performance-to-price ratio; likely the best I’ve come across for a dedicated and fully balanced headphone amplifier. It performed admirably with my Sennheiser HD800, Audeze LCD-X, Hifiman HE1000 and Grado PS1000e headphones; how’s that for added versatility? Never did it leave me wanting more power or head-room; instead it just kept on delivering incredible sound quality and performance. Throw in the more “entry-level” price point and for me it’s a no brainer for someone on a budget looking to drive even some of the most demanding top of the line headphones. Kudos to the folks at Matrix Audio for delivering such a wonderful product at such an impressive price point. This just goes to show you that you don’t need to spend a bundle to hear great sound quality!

I would like to thank the good folks at Matrix-Digi-USA.com (the only US authorized distributor in the United States: http://matrix-digi.com/en/Partners/find.html#North) for the opportunity to review this wonderful amplifier and broaden my horizons on just how well more economically priced amplifiers can perform nowadays.