Disclaimer: Mike bought his HP-A8 from Jaben Indonesia. Edd received a loaner from SCV London. This is a double review. Standard text is Edd’s. Italics are Mike’s.

At the heart of the A8 is a 32bit Asahi Kasei AK4399 D/A converter. An Asynchronous, Class 2.0 USB supports the transfer of audio up to 24bit /192khz, as do the other digital inputs. There is also support for DSD files (DSF only, not DFF). This is a downloadable SACD audio format, which (at the moment) is only supported via the SD card reader on the back of the machine. For non-computer related digital audio the HP-A8C has two optical, one coaxial and one AES/EBU input, along with one optical and one coaxial digital output in case you feel the need to convert USB to another external DAC. With the added ability to up-sample any of it’s digital signals (x2 or x4) this is a feature rich high-end machine.

The fully solid-state, completely discrete headphone amplifier is capable of driving pretty much any headphone you can think of. For those with any analogue devices left, or if you’re lucky enough to own a better DAC, there is a pair of analogue inputs to use the headphone amplifier independently. Gain is selectable from 0 to +20dB (0.5dB steps) if you can find something that struggles with the default levels, which I couldn’t. Even headphones as demanding as the Hifiman HE-6 should feel right at home here, which is an impressive boast indeed.

 

The Sound

The Fostex HP-A8 does digital to analog decoding on an entirely different level than anything I’ve heard before. Based on AKM’s AK4399 D/A chip, this device is capable not only of projecting an uncanny sense of space and soundstage, but far more than that, the sound of a particular recording I’m playing through it. As I’m switching from one CD to the next, a constant sense of awesomeness struck me over and over again. It’s like being there during the recording session, plugging your headphones directly in the producer’s mixing table. We’re talking a far more intricate level of detail retrieval, yet revealed in such an effortless manner by the A8. This is nothing like I’ve ever heard before. It’s not as grand sounding as the Ref7.1 DAC from Audio-Gd, but the Fostex does things I don’t even hear on the Ref7.1.

Even now I’m still awestruck when I play different CDs through the A8. Not only do I get to witness different musical styles and genres, but I actually get a more complete picture of the recording than I was previously able to hear. Even after witnessing the garbage-in, garbage-out principle on other DACs, I’m truly blown away by the amount of information that good old 16/44.1 CD contains. If they were able to implement this level of sophistication on mainstream priced CD players, surely, people would not bash CDs for being digital sounding and inferior to LPs. The Fostex HP-A8 is living proof that the so called “digital” CD sound is the fault of sub-par Digital-to-Analog conversion, a complicated process that turntables don’t have to hassle with.

What I’m hearing is not only the subtle little sounds in the recordings, any half-decent DAC these days does that, but more than that; the color in the recording! From analog recordings taken in the 60s with their thick and grainy sound to the super-clean audiophile digital recordings. Not only does the technology behind a recording, but the particular set up of a recording and the steps taken in the mixing and mastering, somehow contribute to a particular “look” of a recording. All revealed by the Fostex in such an effortless manner.

Audio gear with high transparency tends to be of the dry and clinical type. I can’t say that about the Fostex. It’s a very smooth sounding DAC for sure and clearly the smoothest sounding DAC I’ve listened to. If you like the smooth sound of the HP-P1 i-Device DAC/Amp or the HP-A3 USB DAC/Amp, the HP-A8′s sound somehow reminds you of the two but with technicalities that are not even close to be compared.

Now remember how I said that transparent DACs tend to be dry and clinical? The Fostex is definitely not dry! I wouldn’t be able to enjoy any dry sounding DAC with Sennheiser’s merciless HD800 so definitely there is some coloration here: a smooth Fostex sound with a warm and musical tonality. But what keeps me puzzled is somehow, perhaps a function of über-level resolution, the smooth Fostex sound is able to keep itself from clouding the recording. It doesn’t polish the recordings like some DACs with a tube output stage tend to do. It’s smooth yet brutally honest: one recording to the next, I’m getting a clear picture of the entire look of that recording.

 

Besides the A8, I got some ear time with the rest of Fostex’s headphone amplifier range as well and I must say that I’m most impressed by how consistent their presentations are. The main differences between them are their connections and the technicalities of their sound. The tonality is well balanced throughout, all display a clean and neutral sound that doesn’t jar your senses or feel artificial. This seemed to make them friendlier to a larger number of headphones than amplifiers with a more characteristic coloration. This is transparency as it should be, very detailed but smooth and not cold. The A8 has these features and takes smoothness, subtleties and soundstage to another planet.

Good amplification often brings with it a nice blend of two quality traits, often considered mutually exclusive in lesser equipment. That magic is infused in the A8′s sound as a healthy dose of speed, without the typical tendency of over-brightness in the upper ranges. It’s smooth and articulate treble does wonders to crisp detail and listening for long periods never fatigues. The low frequencies get enough attention too. Bass is tight and well defined without losing weight or impact. The mid-range is perhaps even more impressive, feeding off the high’s lush smoothness and the low’s refined texturing to build a deeply involving experience. I felt an emphasis in the mids, but certainly not overdone and I loved it’s sublime clarity of presentation.

A smooth balance of power, that is both delicate and authoritative, seems to be the hardest thing to do with digital sources and this is where the A8 delivers it’s magic. Although it will take up to 24bit/192khz (through all of it’s digital inputs) it excels with good, old CD quality. Let’s face it: this is the format that most people’s music will be in. After the silky smoothness, the next thing that struck me about the A8′s sound was the soundstage. It impresses hugely! Not only is the throw of instruments both far and wide, it’s also endowed with a sense of natural precision, an effect amplified by superb instrument separation. This rounds off a three-dimensional feeling that brought a lot of music to life in a big way. This effect is emphasized with headphones that already share this trait, so it really warrants a good set of headphones to get as much out of this as possible.

Although compressed music is handled well, the only problem is that uncompressed is just so much better. It seems like any extra detail that you can throw at the A8 further aids a more smooth and delicate presentation. In fact, never before have I noticed so much of a difference between compressed and uncompressed formats, and I see this as a true testament to the refinement and transparency on display here.

 

Comparisons

At one point I was comparing the Fostex to the Eximus DP-1, another highly regarded high end DAC/Amp box. Slightly warm but overall still a fairly neutral DAC, the Eximus didn’t have that flexibility in the sound that the Fostex has in terms of revealing the whole look of the recording. What I mean is, moving from one album to the next, I hear less of the album’s color on the Eximus than what the Fostex reveals. The Eximus, to me, is more in line with my experience with DACs. At roughly the $3K price tag, it’s very spacious sounding and with a good warm tone, and overall the performance is good. It’s just that the Fostex accomplishes much more than that. Before this I often raved about the KingRex’s UD384 DAC. The moment I heard the Fostex, I knew that the Fostex is on an entirely different level. Yet I went ahead and compared the two anyway, only to find that the difference is even bigger than I first thought it would be.

 

Headphone Pairings

The SoundMAGIC HP100 headphones are best for me with a little extra punch in the lower frequencies, though they are already impressive in this regard. A fantastic headphone and a great value! The A8 doesn’t provide that bass body but what it does to the rest of the frequencies and soundstage is nothing short of stellar. This was the least impressive headphone combination that I had, but only because of my preference of tonality shift, or lack thereof, and that’s a petty criticism. The highs, which can be a little overbearing on lesser amplification, sound nicely controlled here.

Although the Beyerdynamic DT880 600 Ohm has less warmth than the SoundMAGIC, they manage to be great despite it and the A8 propelled them to a place of abundant detail and powerful presence. The bass here actually seemed to get a healthy boost in weight once you give yourself a little time to sink into it’s presentation. Soundstage is one of the DT880′s greatest abilities and that was brought even further out by the A8′s amplification.

If you’ve read my previous review you will know that I have some problems with the V-Moda M-100, namely it’s overzealous bass and lack of midrange, but the A8 made the M-100s sound almost acceptable for their price… even for me! If you like them already I can’t help but think that you would love them on this amp, but as I said in their own review: at ten times the price the A8 is no solution. With electronic music I didn’t even need any EQ for the M-100 while connected to the A8. This really is saying something because I found them very lack-lustre and harsh on most other amps, even the Audiolab M-DAC. I will iterate it here because I seem overly harsh on the M-100. It really isn’t a terrible headphone! It’s possibly the greatest full-size fashion headphone ever made. It’s just not an audiophile/ jack-of-all-trades/ HiFi headphone.

I noticed a statement on the Fostex marketing material for the A8 that recommends pairing it “with the Fostex TH900 headphones for excellent results”. I can confirm that, despite sounding like marketing fluff, this is a true statement indeed! Although I need to illustrate the A8′s abilities as an independent device, let me assure you right now that this is no one-trick-pony. The A8 is a very capable machine at driving many headphones to truly amazing levels of quality.

Right, now a little about the TH900…
I was simply blown away by the TH900 in general… but with the A8? Wow! I can hear with every fibre of my being that these two were tuned to be connected to each other. The amplification of the A8 makes a lot of sense anyway but with the TH900 it’s synergy is just perfect. The strong bass of the TH900 gets suitably controlled by the A8′s fast and tight low-end amplification. Similarly the mids and upper ranges are full of detail and can be a bit punchy normally but the A8 keeps them in check.

Although I will be doing a full review of the Fostex TH900 headphones next, I couldn’t finish this section without at least brushing on the topic of the TH900 vs the Denon AH-D7000, while connected to the A8. For those who don’t already know, the D7000 is almost identical to the TH900 in shape. The TH900 is coated in a gorgeous red lacquer but it has wood underneath, just like the D7000 (albeit a different type of wood). Both models are made by Foster Electronics (of Japan) and thus share a lot in common inside and out. The D7000 has recently been replaced by a very different model and is no longer available to buy, but fortunately I happen to own a pair. Comparing these two on the A8 was very easy since it has 2 identical, full-size headphone outputs. Well… listening to these two together it’s clear that they come from the same mould. The presentation is very similar, both are considerably bass heavy, but through this quality of amplification they make a good case for neutrality. Their entire range punches with similar authority, yet it’s controlled under a smooth tonality. The Denon is great here, probably the best I’ve ever heard them, but the TH900 is… I’m sorry for my wallet’s sake… just much better.

 

The Built-In Headphone Amplifier

A lot of the magic in the Fostex’s sound happens in the built-in headphone amplifier. The moment I take the signal out, through a pair of interconnects to a separate headphone amp, a lot of that effortless resolution gets filtered. This is why amp builders try to keep the length of a signal path to a minimum. Obviously, no interconnect is as short as a trace in the PCB. This is why most of my listening with the Fostex is done through the built-in headphone amplifier.

The good news is that the A8 has an onboard headphone amplifier that’s worthy to be used alongside its DAC. So good was the headphone amp, that I didn’t see the need to pair it to another amp. Usually the problem with onboard headphone amplifiers is that they are limited in power. Not the A8. Max the gain (up to +20.0dB with the latest firmware) and it has enough juice to drive the Hifiman HE-6. Yes. Not as satisfying as the RSA Dark Star or the Burson Soloist but hey, it’s an onboard headphone amp that has more power than a lot of dedicated headphone amps! Throw in a Hifiman HE-500, HE-400 or the Audez’e LCD-2 and the A8 has plenty of headroom left with all of them. With the HE-500, for instance, I’m playing at -25.0dB on the volume control. Plenty of room left with the maximum level at 0.0dB.

Both volume and gain level is adjustable via the big knob on the front. It’s not an analog pot behind the knob though; volume is adjustable from -100.0dB to 0.0dB on every gain setting you choose, with 1dB increments. The gain level is adjustable from 0.0dB to a whopping 20.0dB with a 0.5dB increment. That gives you an extremely accurate volume control for both the most sensitive IEM or the Hifiman HE-6. Channel imbalance? None what so ever.

 

Build

Everything is so well made on the A8 and the little interactions make it such a joy to use. Connecting the Fostex TH900 headphones to one of the headphone sockets shows such precision engineering. It’s reminiscent of closing a luxury car door: sublimely smooth but not loose, a perfect fit to the micrometer. The volume dial is similarly flawless and a total joy to interact with. I’m not a fan of stepped attenuators, because it can be hard to find the desired volume and they’re just not as nice to turn as a smooth dial, but not here. This is stepping done right and it retains a wonderful smoothness in operation. You’ll just want to keep touching it.

 

DSD Playback

The menu interface is rather fiddly to operate via the tiny dial next to the volume but the browsing of DSD files (which can be sourced from ‘HD-Tracks’ or the ‘Blue Coast Records’) is an even bigger annoyance. Accessing these files can only be done through the included remote control which feels rather cheap, small, awkward to use and is unreliable. The only controls are “play/stop” and “skip track”. There is no “fast forward / rewind” and more crucially, no “folder / album” browsing. I can’t imagine people wanting to use this feature due to the rather poor interface and controls. Even getting the machine to recognize the files will put some people off. There is talk of the A8 supporting DSF play over USB and I for one really hope that this feature is added soon. Until then, if you have DSD files, or want to try them with the A8, my recommendation would be to use the (free) Foobar software on PC. You can then download the SACD plug-in that can down-sample DSF files to PCM on-the-fly (either to 44.1, 88.2 or 176.4khz). The A8 will then take that signal via the USB connection. You can also listen to .DFF files this way too by using a plug-in by Kode54. These are alternative DSD files more common among studio users.

 

Final Thoughts

Browsing the technical data and photos for the Fostex HP-A8 might inspire lustfulness, but it’s the sublime sound quality and beautiful build that will really impress. If you’re looking for a great DAC, and a stunningly transparent and smooth headphone amplifier with a ton of inputs and endless clean power, then I highly recommend an audition with the A8. Give it a listen with some nice headphones and I doubt you’ll want to put it down. Unless you just picked it up to see how heavy it is.