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.
[adrotate banner=”48″]





John Hernlund
Fostex boxes are under-pinned mostly by their DAC sections, and seems to be where they spend much of their budget. The A3 and A8 both use Asahi Kasei DAC chips, and share many more similarities with one another relative to the A4 and A8. Of course, it ultimately depends on the pairing between the DAC, amp, and cans. But still, it is difficult to fathom that the A4 is more a “mini A8” than is the A3.
hersagam
Hi mike..do you think fostex hp a4 is a good pair for senn hd650? or is it better with pan am? thanks
Mike
It’s decent overall. The DAC is good but the 650 shines better when it meets a tube based amp. So overall I’ll go for the Panam. Unless you want to pair the A4 with another separate tube amp.
hersagam
i see..thanks for your enlightenment mike..:D
Mike
You’re welcome 🙂
Juan
Mike I also got HD 650 Cans. I currently have the fostex hp a4 that i paired with my audioengine hd6 speakers and they sound amazing (dac on the fostex is amazing)
I do feel like my hd 650 cans so I went a head and order the objective 2 Amplifier to pair up with my fostex. How do you think it will pair up with Objective 2? I will be using the RCAs Out to pair it to the objective 2 and the optical out to the Audioengine HD6s
ro
Would the iPad Air be able to connect to this via USB using the Lightning to USB Camera Adapter?
Mike
Thats a good question, I haven’t tried that sorry.
Niice Ekasith
Hi mike, thank u for the very nice review. Like to ask for your suggestion if this fostex is the good pair with Alessandro MS Pro-i sonically? I listen mainly to piano,acoustic guitar music, female vocal, middle pace pop. I like neatral, smooth and detail sound yet good body mid range. Thank you and appreciate for your advice! 🙂
Mike
It should be a good pairing with the Pro for your music, yes.
HZE
Great review as usual Mike! Can you elaborate more of the pairing result with LCD-2 compared with ALO Panam? Which one is better? Thank you.
Mike
I like them both. The Fostex is more detailed, more articulate, more impact. Usual strengths of a solid state sound.
The PanAm has a more spacious sound, more midrange bloom, cleaner sound. Usual strengths of a tube based product.
Lian Hui
Hey Mike, just wondering if it works well if I use the A4 as a DAC pre-amp while connecting the headphone out of the A4 to the input of PanAm. Do you think it would sound good? People have been saying A4’s amp section is lacking.
Using it with Fostex TH600. Thanks in advance.
Mike
Of course you can do that
Scott Love
Hi Mike, I’m really new to the audiophile community and just purchased a pair of Beyerdynamic DT990 600 ohm, I was wondering if this was a good amp to pair with them, and if not could you point me in a good direction?
Mike
Hi Scott,
Not really an expert on the DT990 amp pairing… Something with a tube would be nice I guess.
Aakshey
How does it compare Asus Essence One / Regular / Muses edition?
Thank You
Aakshey
Mike
The Asus DAC is more detailed and more resolving. The headphone out is better, more dynamic, more linear on the HP-A4.
Aakshey
Thank You so much for the prompt reply Mike. Also,
1. Was your above reply with respect to the Standard Essence One or with respect to the Muses edition?
2. As overall units, one on one, do you think Muses edition as an overall unit is a step up from the HP A4? 🙂
Thank You so much in advance!
Aakshey
Mike
It applies to both the standard and Muses. The standard is already more resolving, so the Muses is even more.
Gonçalo Dourado
Hello,
I was under the impression the Headphone Ampo on the Asus was better and more powerful. Do you prefer the one on the HP-A4?
Cheers!
Andy Q
Hi Mike, is the Fostex HP-A4 USB powered? I can’t see any separate power inputs. Also, do you think it is a good pairing partner for a Mad Dog 3.2? Thanks Mike.
Dave Ulrich
It is USB powered.
Mike
It is USB powered.
I like it with the Alpha Dog. Don’t have a Mad Dog 3.2 around.
sc_low
Hi Mike,
Wondering how is the HP-A4 compared to the Centrance DACport in terms of bass impact, mids, overall musicality, etc?
Do u think its worth to upgrade to the HP-A4? What would I expect from this upgrade?
How does it pair with the HD25-1 II? from EDM to slow paced music?
Many thanks Mike.
Mike
I think the A4 is a clear upgrade from the Dacport. Difference of ~3-4 years of technology.
It’s better for the HD25-1 too, make the sound more spacious. Both are dynamic sounding but the A4 is a lot more spacious and with lower hitting bass.
sc_low
Hey again Mike, what are your views on pairing the hp4 with the DT770 32ohms?
I find this pairing to be nice, but sounded abit dry, lack of mids?
ohm image
I was surprised at how much power the HPA4 offers via USB, and by the immense array of options it has.
Sylvain Gaudet
Hi! I’m new in the market of dac/amp. Looking for one for my workplace to use with my new Grado Gr10. After some research, I can’t decide between this one Fostex HP-A4 and the ALO “The Island”. With one has better sound stage and depth? Or any other suggestion in this price range? I listen a lot of instrumental, minimal music. Thanks!
EL
Hi mike, nice review. I wanted to know whether the RCA out behind a line level output?
longbigbonzeelephantfish
We’re discussing this over at Head-Fi too!
http://www.head-fi.org/t/684059/fostex-hp-a4/
L.
yay!
Nick Tam
This just gave me an idea…
A4 DAC out to Bottlehead crack
Mike
And that too
Robert
Hmm wondering how the T90 would do with the HPA4…
jpbas1
As an owner of the TH600 and contemplating the purchase of the HP-A4; would you recommend the union?
Mike
It has enough power, but I still prefer a tube like the Crack for the TH600
jpbas1
Thank you, Mike!
Erelde
Hello 🙂
I’m currently considering buying an Senn HD 800 (after testing it for a while in a showroom) and I’m wondering if I should take the A4 or the A8 to pair it with ?
dalethorn
From what I see in the specs, the A4 is very low powered and would be insufficient for the HD800 (100 mw at 32 ohms).
Erelde
So as I thought, it will be the A8
I expected that (I read the specs a bit too fast ^^)
Max Chee
Hi I would like to know if this will pair well with a HD 650
dalethorn
From what I see in the specs, the A4 is very low-powered, and while it will probably work fine in very quiet places (since the 650 is open-back) at moderate volumes, you might lose some of the dynamics with the 650.
ExpectationGap
Thanks for the review Mike. Have you (or anyone else) tried the HP-A4 with the LCD-XC?
Gonçalo Dourado
Hello,
I am searching for a new desktop DAC/AMP combo.
Currently I am torn between either the HP-A4 or the Asus Essence One.
My current headphones are the Mad Dogs 3.2. I plan on adding a pair of active studio monitors like some BX5a or BX8a. In the future I might get some other headphones like some HD650’s or such…
Based on this, what would you recommend?
Cheers and thanks!
Gunshots ByComputer
I live in Japan. And they don’t sell a lot of the amps or dac/amps you can get in the USA. Fostex is one of the few they sell in both countries (plenty of boutique makers that sell solely in their country of origin and I can’t find good info on most of the Japanese ones). You say this sets a new bar for 500$ amp/dacs? Well its about 350 USD in Japan right now… so I guess its a real bargain. I have an O2 and Odac at work, I need something for home… This one is looking like a great contender.
George Lai
Living in Japan, you can get things people can’t get in USA, for example custom IEMs from FitEar.
dalethorn
Not to mention a ton of headphones (AT’s esp.) we see on Amazon as “Japan Import Only”.
Gunshots ByComputer
I have the ATH-im02 and IM70s. love them both. Japan only right now. But I can’t get great stuff like Schiit over here. I am about to buy a transformer so I can. I also can find ZERO sites like head-fi, innerfidelty, or headfonia in Japan. Most reviews on this stuff are done on blogs. Not to mention my Japanese is no where near good enough to read a blog and google translate is horrible with Japanese. Prices on some stuff is great. Fostex gear and most of the EU gear, Sen and Beyer is SUPER cheep in Japan. But my Phillips X1s AND my V-moda M100s broke after a few months. Sure the warranty covered it, but I had to pay shipping to the USA.
dalethorn
When I would send stuff to the Philippines from New York, I used a shipping service that was sourced out of the Phils by the guys on that end, and cheap. Unfortunately they couldn’t get stuff to me as cheap since it had to travel another leg after New York that their courier couldn’t do themselves. Point is, since v-moda apparently can afford warranty service to Japan one way, you should have a way to ship cheaply to them – either by using their shipper or hitching onto another carrier that has a better rate.
A83
Hi, thanks for great reviews! How would you say it compares to the Schiit Bifrost Uber w/ Gen 2 USB? Thanks.
Caspian Kai
Hi Mike. Great review. I’m pretty keen on getting this to go with my TH600 as I thought it’d be a good combo, but I saw you said already in another reply that you prefer the th600 with tubes. TBH I haven’t tried tubes but I generally prefer hearing the headphones for what they are and not further colouring things much; detail/clarity and speed of solid states I usually like. Is there a solid state dac/amp combo for up to $1000 you’d recommend for the Fostex HPs? Or how about the Woo WA7, I have heard very good things but the DAC may be sub par?
Gabriel Ross
Mike, Listening to my Telarc Chopin on my new A4; crisp,solid,amazing! Thanks for the review. It is an upgrade to the E17. Again just needed to say thanks. And thanks for “Headfonia Tips on Low Gain”, helpful with the A4.
Biergourmet
I’m thinking about: Fostex HP-A4 vs. Teac UD-301 vs. Matrix Mini-i 2014. Any opinions?
Gunshots ByComputer
I am sitting here about to hit the check out button on the TEAC UD-301.
But the fostex is sitting there in the back of my head. We don’t know what is under the hood on the fostex. The TEAC has a monaural circut running DUAL burbrown DAC chips and DUAL mose amp chips. Plus it has balanced XLR output giving out major options down the line if you want to add a serious amp like the TEAC 501 dedicated headphone amp. which one to get?!?
Gunshots ByComputer
I don’t get it. I have been reading reviews about the A4 and the A8. The reviews are all over the board. The auther says he doesnt care about the DSD…. but that is one of the reason I came BACK to A4. For a 500$ DAC to have DSD is nice. And the UI is nice. The Denon has DSD too for nearly the same price and it has no UI at all. Just a power button and and volume pot. On other website like WhatFi they give the A8 a pretty bad review. I am just seeing so many mixed reviews about the fostex and it neither of them get much love over at head-fi either. But for the price of both of these DACs I really can not find many alterntives at all. I am going for the TEAC UD-301 for sure. that one is for home use. But what about this office. A4, A8, or….. the Marantz HD-DAC1. For the cash the DAC1 seems like much better deal than the A8. But for the sub 500 catagory. A4 and UD-301 are the only contenders in my book. I have been searching for days. There are a bunch of boutique shops like Audio-GD. hand made custom stuff from China that is amazing for the price… but its boutique stuff from china? Is it any good? I don’t know my O2 DAC and AMP are amazing… but not perfect either. very rough around the edges like you would expect from boutique sized company.
dalethorn
I’ve been watching this waiting for someone to answer, but it looks like they won’t, probably because Teac doesn’t usually show up in headphone audiophile communities. I don’t have knowledge about the brands other than Fostex, which I’d recommend. When it comes to features like DSD, I might consider an unfamiliar brand if that were the only way to get DSD playback. But compatibility with the DSD format is no assurance of sound quality that takes full advantage of the bitrate. As to reviews, I trust the reviews here, and I might even sample some reviews at head-fi, but in that case I’d have to research carefully because they’re open to everyone, regardless of track record. Bottom line is I don’t read reviews at sites other than dedicated headphone audiophile sites like Headfonia, unless I just need to scan those reviews for features and specs. I don’t want to beat up on sites like WhatHiFi, but their headphone reviews are way different from here, and I can’t imagine what they’re hearing out of those headphones – something way different from what I hear or read here.
Headfonia_L.
Thanks Dale!
Gunshots ByComputer
somewhat off topic (from my previous comment). I have the ODAC at work and think it sounds great (I went a head and just bought the Marantz for home use). do you think the the HP-A4 is a worthy upgrade, if used just as a DAC? I have a dedicated amp. I can add DSD for 150 bucks by adding a Schiit Loki to the system. I am not saying the ODAC is an “beast killer” but I do feel for its price it can not be beat.
dalethorn
Since I can’t do that comparison I don’t know. But each is a quality DAC, so whatever differences you hear would likely be more the manufacturer’s tuning than sound quality. Unless the HP-A4 has some kind of problem in your system when used as a DAC. If you can easily return the HP-A4 for refund, it should be worth trying. The good news is – unlike an amp you don’t have to worry about power issues (i.e. low-power noise and channel imbalance with IEMs or not enough power for big headphones).
dalethorn
Doing some more research on the Teac, it seems they require you to use Teac software that’s a music player – not just a driver – to get proper hires playback of 24/96, 24/192, DSD etc.
Gunshots ByComputer
I think that is true of few DACs out there, but I think you can add the dacs driver to the list of Foobars component list, and foobar is able to use that dac.
I was just talking to a guy on Head-fi that was having trouble with THIS very Fostex dac in Foobar. I recommended he tried doing just that, adding the fostex driver to foobar. Problem solved. I would assume its the same with the TEAC.