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Initial Impressions of the Fostex HP-A8 DAC Amp

post #1 of 45
Thread Starter 

Please bear with me, I'd consider myself still a noob when it comes to desktop DAC/Amps. Although I've heard a few DAC Amps in quite a few public headphone festivals, most aren't heard with my headphones nor my source tracks of music. And I'm still mostly learning from the gurus here in this forum and from Japan Head-Fiers.


So this initial impressions will be somewhat unstructured and a lot of it will be based on a DAC/Amp I'm familiar with, the Benchmark DAC1 Pre. I won't get into the specs of the HP-A8 as you can find the info easily yourself. Or please go here for its specs :-







A little bit of background...

of my pursuit of this DAC Amp. I've owned the Benchmark DAC1 Pre for about 7 months and although it's a great DAC Amp, I was getting somewhat bored of it's 2D sound - both as as DAC to my Stax setup, and as a DAC Amp for my Fostex TH-900 headphones. Furthermore, since I took my Benchmark DAC1 Pre & Stax setup to the Fujiya Spring Headphone Festival 2012, other chaps from Head-Fi brought in other DACs (Yamamoto, Eximus, etc.).


Last month my wife & I went to Fujiya Avic to demo the HP-A8 but in somewhat more "controlled" environment. I brought my Benchmark DAC1 Pre, my DX-100 with optical cable, and my Fostex TH-900. My wife (who's not technically inclined but has as sharp ear) was my "other pair of ears". Spending about 30-40 mins there with Fujiya's HP-A8 demo, we listened to a few tracks rather carefully and concluded then the HP-A8 was more detailed, more 3D and basically a leap improvement over the Benchmark DAc1 Pre.


As such I went back the next day and bought the last HP-A8 they had on the shelf.


To my disappointment, at first listening, the new HP-A8 didn't sound the same as the demo unit. It sounded almost the same as the Benchmark DAC1 Pre. And so the burn-in began. Although SQ did change somewhat after 8 hrs, it didn't change much. A few days later and 100 hrs burn-in later, the SQ did improve incrementally but still not the vast difference both of us heard at the store. At that point, I felt the purchase wasn't worthy of an upgrade that I was looking for. However after talking to Currawong, whom advised burning in to 350 hrs at least, and we talked about power conditioners, strips and cord, I further ended up picking up the VH Audio Flavor 4 power cord, and Oyaide MTB-4 power strip.


The result after 250 hrs of burn-in and power source upgrade for the HP-A8?






The setup is as follows :-


DX-100 with 16/44.1 -> 24/192 tracks of 80's pop, classical, jazz, and country

Headphones/earphones used include the Fostex TH-900 and FitEar TO GO! 334

Switching between the Benchmark DAC1 Pre and HP-A8 involves the headphone jack naturally, and optical cable from the DX-100.

Again, as mentioned before, this has a lot to do with comparing it against the Benchmark DAC1 Pre that this DAC Amp is supposed to replace.


Despite the long in and power source upgrade, for most of the 80's pop music (Michael Jackson's Thriller, Footloose, and Top Gun all in 24/192)  it was very difficult to differentiate between the two DAC Amps. Even Michael Buble's It's Time (16/44.1) with a fair decent amount of vocals and acoustic instruments, the HP-A8 and Benchmark were very similar. At times it was difficult to tell the difference between the two. This was tested with both headphones/earphones and confirmed by my wife.


The difference between the two was much clearer with Isaac Stern's Four Seasons (24/192), Lana Del Rey's Born to Die (24/44.1), Buena Vista Social Club (24/96), and Anne Murray's The Best...So Far (16/44.1). The presentation of the HP-A8 sounded more 3D, smooth yet detailed, and more immersive. The difference isn't night and day, but at the same time isn't so subtle  - it's obvious enough to pick up after critical listening. Where in pop music or modern vocal jazz (Michael Buble) frequency response sounded pretty much similar across both DAC Amps, for tracks with strong vocals, or natural acoustic instruments the bass seem to extend a little more deeply and trebles sound more clear and transparent. But it's more the immersive 3D presentation that captured my attention initially.


Going by memory of the Eximus DP1, although wasn't as detailed HP-A8, I would place in between the Benchmark DAC1 Pre and the DP1 in my DAC Amp scale for specific genre and type of music. But for the 80's pop tracks I had, as you can guess I'd treat the Benchmark and HP-A8 equally.


Another note I'd like to add though, although the HP-A8 and Benchmark sounded rather similar, the HP-A8 was just a tad more mellow than the Benchmark. The way I felt was the Benchmark had more of a slam-in-the-face impact but somewhat 2D, whereas the HP-A8 was more 3D, it was also somewhat more subtle and mellow in impact. For example, with some pieces of Vivaldi's Four Seasons, I was anticipating the next (chord?)<whatever!> to come in with a wham (at least with the Benchmark) but with the HP-A8, it just creeped subtly.


However, on the other side of the coin, with the HP-A8's 3Dness,  found I could hear some instruments in some classical pieces more clearly. Whereas with the Benchmark's 2D slam, that instrument drowned in the slam and everything sounded more congested. This is more apparent in lower volumes.


Finally, I also did test the DSD capability of the HP-A8. After some fiddling with filename lengths and DSD formats (only DSF accepted, not DFF!!), the HP-A8 does play DSD files very nicely. Across the board on clarity and transparency, the same DSF file sounded better via the SD card than via Audirvana Plus (which does convert to PCM in real time before output via USB). I'm quite satisfied with the SQ of DSD playability.


Non-SQ Aspects of the HP-A8

Although DSD sounded nice, getting it to play it is a real pain. Firstly, only DSF is accepted, not DFF. Luckily my SACDs are in ISO as such I just have to re-extract into DSF. Then the next problem is a 30 character limit in the file name. For some strange reason even for some files with less than 30 characters, the HP-A8 wouldn't recognise it. Also all the DSF files have to sit in one folder. So really the DSD capability is really more a proof of concept than for practical use. Fostex is supposedly working on a DSD over USB driver but they're having some issues. Once they've released it, I'd be much more satisfied with my HP-A8.


Also having only unbalanced RCA output is a little tedious. I do wish Fostex included balanced XLR which I'd feed into my Stax setup. But for now, I have to use unbalanced.








Overall, I think the HP-A8 is a decent desktop DAC Amp in the similar grade to the Benchmark DAC1 Pre. As to whether the HP-A8 is worth it's price, I think it really depends on where you live. In US, the HP-A8 is USD$2000, whereas the Benchmark DAC1 Pre is $1400. In  that scenario, I personally don't feel the HP-A8 is worth the $600 difference of my money.


However, as I'm in Japan, where the HP-A8 is approx USD$1300, and the Benchmark DAC1 Pre is sold here for USD$1730, the HP-A8 worth it's value. If Fostex gets the DSD over USB driver working, the HP-A8 will show it's true capability.


P.S. Apologies for the very scattered and unstructured review. I may come back later on to clean it up.

post #2 of 45

Many thanks, great job.

post #3 of 45

Thank you for your honest opinion between the two gears.  Do you have a dedicate amplifier to allow comparison b/w the two unit as source only?  I'm curious which will come out on top in term of DAC.  I never like the DAC-1 headphones out as it was slightly harsh and 2-D sounding.  However, the unit that I am familiar with was the regular DAC-1 and not the USB or the Pre version.  

post #4 of 45
Thread Starter 
Hi Purk,

I can can try tonight a compare & contrast of the Benchmark DAC1 Pre & HP-A8. I did try that at one stage a few weeks back but I have to admit I have forgotten the difference - anything I say now will most likely be placebo.

The switching back 'n forth is a slower process since my Stax SRM-727A has only 1xRCA unbalanced.

Will get back to you on the results.
post #5 of 45

The HP-A3 is a solid performer. If this one surpasses his small brother qualities, i want it. tongue.gif

post #6 of 45

Nice review AnakChan! And nice gears too at there biggrin.gif


Seems like we both really notice about how 3D is this DAC, for me that's the first thing stroke me when I tested them.


I still have one problem, it is about the SD Card input, because when I tried today, the HP-A8 always insist said "No File" in my SD Card.




Btw, just adding info to this thread, I copy paste my initial impresion from the other thread:


Originally Posted by TheMiddleSky View Post

After tested HP-A8 for two days, I think this combo box is really a great stuff!


My initial impression so far:

- HP-A8 indeed a Fostex product, as they have the same sound signature (from HP-A3 and HP-P1).

- HP-A8 sounds so linear to my ears, but they don't sound cold, harsh, or boring. They just sound smooth, relax, slightly on warm side with very spacious soundstage.

- Compare to Lavry DAC10 as combo box (DAC+Amp), HP-A8 easily eat Lavry in term soundstage image (more spacious and more accurate), more detail, and cleaner sound while still maintain the right "warm" tonality.

- Compare to Eximus DP1, I think both of them has very great technicalities aspect, but has different presentation. DP1 has more lively sound, more treble energy and bass impact, while HP-A8 always sound smooth and relax. 

- Amp section wise, Eximus DP1 indeed is more powerful. I think Fostex's amp is more suitable for easy to drive cans, so no ortho cans to plug here.

- When I tried with HD800, using some mainstream songs, I have volume around -15db, more than that will sound uncomfortable to me. Note that I am a low listening listener.

- When my friend plug his HD650 with classical recording, he easily can reach the max volume without feel too loud.



*Headphone that I used to test: Sennheiser HD800, ATH AD1000PRM, ATH W1000X

post #7 of 45
Thread Starter 
Originally Posted by TheMiddleSky View Post

Nice review AnakChan! And nice gears too at there biggrin.gif


Seems like we both really notice about how 3D is this DAC, for me that's the first thing stroke me when I tested them.


I still have one problem, it is about the SD Card input, because when I tried today, the HP-A8 always insist said "No File" in my SD Card.




Btw, just adding info to this thread, I copy paste my initial impresion from the other thread:


The SD card's a little tedious. You need to put your files into a folder (I call mine "Music") then all the files have to be short in length (they say 30 characters but I find some need to be shorter). Once you do get it working though it actually sounds really good. Oh yes it has to be in DSF format too...not DFF.

post #8 of 45

Ah I see, so that's what you mean in your review. (Honestly I don't really understand about what you explain about DSD in your review, my bad tongue.gif )


Anyway, tomorrow there's a little "audition party" in our store, hope I can gather more impression about HP-A8 from our local community, and I'll try to summarise all of impresions here too.


Some gears for tomorrow's party:



post #9 of 45
Thread Starter 

Nice gear you have there. If you can find that Eximus DP1 again and spend more time with it, I'd greatly appreciate if you could give me your thoughts on it over the HP-A8 primarily from the perspective of it's resolution, 3D, detail, and smoothness capabilities that's greatly appreciated.


A few weeks back my friends & I did a comparison (found here: http://www.head-fi.org/t/576075/april-music-eximus-dp-1/465#post_8772450) and overall the consensus was that the DP1 still had the edge over the A8 over the above factors but I'd like to get more opinions the DP1 is leaps and bounds over the HP-A8 or just a marginal improvement.

post #10 of 45

I don't think I can get DP1 anytime soon right now.


Some people from our local community (included me) here who already compare them feel that in term of technicalities only, actually DP1 is still take the lead but in minimal margin. So to choose which one better between them is back to personal preference and synergy set-up. 


Note that we compare them as DAC+Amp combo. Not as separate DAC/Amp.

post #11 of 45



I have used HQPlayer to send BlueCoast DSDs to my A8C and it's pretty spectacular. I am also comparing 2L's free 24/192 and DSD demo files and there a discernable upgrade in detail and 'tactility' (YMMV). This is the setup: Windows 7/Signalyst HQPlayer(Trial)> Wireworld Starlight 0.5m USB> Fostex A8C> Audeze LCD2 rev.2


I have a broad range of musical taste (not revealed to avoid hoots of derision) and I don't have a problem with pop/rock on my LCDs or Beyer T5p - which have completely different FRs as you would know.



post #12 of 45

I'm going to roll back on that. I'm only getting 192KHz. Obviously some PCM conversion is going on. Sorry.

post #13 of 45

Here's the latest response from Fostex:


---------- Forwarded message ----------
From:  <info_sales@fostex.jp>
Date: Wed, Nov 14, 2012 at 8:38 AM
Subject: Re: Fostex A8C firware update to support DSD over USB
To: - HPManiac

Dear Sir,

Thank you for your email to our website.

We are working on the beta firmware now targeting the official release
within this year.

Best regards,

post #14 of 45
Thread Starter 

The beta firmware (presumably you mean 2.00b) that supports DSD over USB (or DoP to be more accurate), is out and available on the Japanese site at least. I've been testing the 2.00b DoP and it works reasonably well. It has actually made me love my HP-A8 more and I'm thinking of re-reviewing my review.


There are a few things I've noticed (I don't want to call them flaws, well some of them anyway) :-


1) I do get dropouts occasionally...music stops, then continues. Feels like a buffer overflow of some sort. I've mentioned this to Fostex already
2) When jumping to a track, there's about a 1/2 second "fade-in" - i.e. music doesn't start at the very start. Fostex that this was done by design (to reduce popping noise between tracks). However there are options to disable this "fade-in" though.


For firmware 2.00b :-


post #15 of 45

Many thanks, AnakChan.


I've d/led the 2.01B, which hopefully incorporates the changes you requested. I guess the fact that neither Jussi nor I read Japanese left us ignorant about the updated firmware - but apparently Fostex staff are as well! I will update tonight and see how it goes through HQPlayer.



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