Disclaimer: The Headfonia Store is a Fostex dealer in Indonesia. We’ve been selling Fostex products since last year and there is a big chance we will also sell the HP-A4 (though not yet at the moment)
The HP-A3 which was one of our favorite desktop USB DAC/Amps has been updated with the new Fostex HP-A4. When I auditioned the HP-A4 at Fostex’s head office in Tokyo late last year, I could noticeably pick up the mini-HP-A8 sound signature. Most notable among the improvements were the blacker background and the big improvement in detail retrieval, even if that meant a slight loss of the smoother sound signature of the HP-A3/A7/P1 line up. However at that time they were demoing the A4 with the TH600 which to be honest I’m never too thrilled about. This time, with the demo unit sitting on my work desk, connected to my 1st gen Audez’e LCD-2, I am far more excited about the sound capabilities of the HP-A4. It’s a lot more dynamic than the A3 or even A7. Livelier treble and a punchier bass section. Not exactly the sound signature Fostex is known for (think the T50RP sound as the “Fostex Sound”), which makes me think if Fostex’s more active presence in the Head-Fi circles has infused a little American signature into their tuning. I think the HP-A4 box is driving the LCD-2 pretty darn good, extremely close even to the individually tuned DSP DAC/Amp box by Audez’e themselves.
I don’t know why, though the technicalities are a step below the Fostex HP-A8, this little box is a lot more involving musically than its bigger brother. It’s less laid back, more dynamic, more toe-tapping. I love this little black box! The treble is more present but it’s not a hot sounding box. And though the bass is impactful and dynamic, it’s still monitoring quality bass that lets you hear real details on the lows. The monitoring crowd should be thrilled with the quality this little box presents, as it easily trounces the Benchmark DAC1 (first gen) I have sitting at the store. Not quite Lavry DA10/DA11 level resolution, but at the price that the HP-A4 is being offered at? Being a music first, monitoring second, I would’ve liked a fuller and smoother midrange body because at the moment it’s feeling a slight v-shaped and that the mids section though extremely detailed is a bit dry, a bit too monitoring DAC like. However vocals are spot on in terms of presence, so there is no sucked out vocals or anything like that. But still, not only in terms of overall sound, but even isolated individually from treble, midrange, to bass, there is not an area in the A4 that I prefer the older A3 over.
And I’m not even talking about other improvements that the A4 has over the predecessor. Firstly and foremost, it drives the LCD-2 so sufficiently at low gain. Not ALO Studio Six like, but pretty darn powerful, and at low gain. Talking about IEMs, I can stay at the same low gain level and get a very good amount of control with the volume control as well. Sure there is some imbalance at near zero volume, but which analog pot doesn’t suffer from that problem? It’s such a low level I’m not too worried and if somehow it bothers you, you can always turn down the iTunes volume and skip pass the range where the analog pot is presenting imbalance.
Looking at the backside, you are now given an extra digital out (not present on the HP-A3) as well as a Micro-SD slot. I’m thinking audio playback direct from micro-SD but alas, it’s only there for software updates. Besides I don’t think the A4 has the UI for choosing songs if the playback feature is there. Other than that, it does 24/192 PCM and 2.8MHz and 5.6MHz DSD capability. There is a button at the front that says “Filter” that switches between a slow or fast roll off digital filter for PCM, and a high cut-off frequency (-6.6dB at 185 kHz) or low cut-off frequency (-1.5dB at 85kHz) for DSD files but the effect is so minute you’ll be hard pressed to tell the difference in short listening sessions. On PCM files, fast roll off will give you a more precise feel, like the effect of a faster transients, especially noticeable in the bass. The slow roll off will give a more analog feel, yet slower and more blurry, somehow like comparing the bass characteristics on a Beyer DT880 (fast) to a HD650 (thick but slow). The optimal effect of course depends on the headphones that you use. The LCD-2: I really have no complain with bass speed hence I use slow. It’s smoother and fuller. The HD25 Aluminum for some reason feels a bit slower than the standard HD25-1 on the bass and I like the switch at fast roll off.
While I don’t really care about DSD or 24/192 capabilities, at the end I just can’t help being excited about a box that plays everything I throw at it pretty good. Just about the most perfect balance of technicalities and musicality I’ve seen south of $1000. It has the sound stage, the depth, resolution, separation, but it manages to be so musically involving and toe-tapping. I wanted to say that the HP-A4 has re-set the bar on the $500 USB DAC/Amp but it’s such a cliche statement. Perhaps you the reader can help me with a closing statement.