[MattRG]

  Just wanted to jump in here that I also bought the HP-A4BL today and am extremely happy with it. It drives everything from a TH-900 to HD800S and LCD2 just fine. If anybody has questions about this criminally under-the-radar DAC/AMP let me know. Not enough people here seem to own it considering what its offering at its price point.
 
While I do prefer the sound from my Parasound ZDACv2 / Mjolnir 2 pairing (and I still slightly prefer direct plug-in to the Parasound) this is all just preference and each of these devices cost significantly more. The Parasound (on its own or via Mjolnir 2 with tubes) has a slightly warmer fuller sound. But ZDAC also advertises itself as going after this warmer "analogue sound".
 
On the other hand the HP-A4BL is more strictly neutral but in a nice way its certainly not in any way cold or thin and spectacular for its price point. And this pairs well with Fostex style headphones (my favourite) like the TH-900, etc which have quite strong lower response anyway.
 
The LCD2 and 800S use the balanced connection. I have not tried these two on the standard plug. But on the balanced connection, they get plenty loud at max volume (low gain) and then can get obviously even louder on high gain, but I haven't seen the need to use it yet except on one track (score) that is particularly quiet.
 
If you have any questions let me know. But if the features -- balanced, easy front-facing controls, USB, optical, analogue pre-outs (I use for my desktop AudioEngine speakers) -- then the performance and sound quality I would say are very very good and exceptional for the price.

Thank you for your post.  I'm glad to see the HP-A4BL getting some positive impressions, especially from someone who owns some of the TOTL headphones like you do.  I should be receiving the Massdrop TH-X00's soon and am very curious to see how it pairs, being a Fostex headphone.  

 

[Naim.F.C]

Thank you for your post.  I'm glad to see the HP-A4BL getting some positive impressions, especially from someone who owns some of the TOTL headphones like you do.  I should be receiving the Massdrop TH-X00's soon and am very curious to see how it pairs, being a Fostex headphone.  

The HP-A4BL is an extremely underrated amp/DAC combo imo. I'm honestly surprised it's not more popular than it is. Perhaps Fostex need to work on their marketing lol.

 

[MattRG]

Yes, I would say so.  I also think it's probable that they haven't shipped a lot of the HP-A4BL (which was a 2016 refresh of the HP-A4) either because their dealer's aren't ordering them due to a lot of competition in this space or because Fostex hasn't done a great job of highlighting how good the HP-A4BL is for the price.
 
Either way, we know it's good and I am using mine and enjoying it on a daily basis.

 

[NoteEater]

I don't have a ton of experience listening to all the different headphone amps out there, but I have to say I love the HP-A4BL.  It is not as powerful as the Jotunheim, but powerful enough to drive most headphones.  Currently running a pair of HE400i cans with balanced XLR with the HP-A4BL and I am very impressed over the unbalanced connection. There is tons of headroom when using the balanced cable as well as more clarity/transparency.   I have a pair of Beyer DT880 Premium Black Edition 250ohm cans coming today.  Although not balanced, I am hoping it will be enough power to drive them adequately.  I lie to listen to music loud. 
 
I am hoping the pairing works out well.  I know headfiers feel the Beyers are too bright and maybe that has to do with the amp pairing.  From what I have read about the Jotunheim, I would imagine these Beyer cans would get very bright.   The HP-A4BL may provide a more neutral character with the Beyer's.  I will post back with my experience as well as a more comprehensive review of the HP-A4BL.
 
Quick question:
 
On my portable DAPs I can use the toslink to coaxial digital adapter.  The HP-A4BL does not have a coaxial digital in but an optical in.  Can I use a toslink to optical cable like this one instead on my FiiO X5 and/or iBasso DX80 with coaxial out?
 
https://www.amazon.com/FosPower-Toslink-Digital-Connectors-Strain-Relief/dp/B00T8HWUVS/ref=sr_1_3?s=aht&ie=UTF8&qid=1485275598&sr=1-3&keywords=toslink+to+optical

 

[MattRG]

I'm sorry to say I don't know the answer to that question.  You might have more luck in the help and advice section with that particular inquiry.

 

[Limu Shirin]

  I don't have a ton of experience listening to all the different headphone amps out there, but I have to say I love the HP-A4BL.  It is not as powerful as the Jotunheim, but powerful enough to drive most headphones.  Currently running a pair of HE400i cans with balanced XLR with the HP-A4BL and I am very impressed over the unbalanced connection. There is tons of headroom when using the balanced cable as well as more clarity/transparency.   I have a pair of Beyer DT880 Premium Black Edition 250ohm cans coming today.  Although not balanced, I am hoping it will be enough power to drive them adequately.  I lie to listen to music loud. 
 
I am hoping the pairing works out well.  I know headfiers feel the Beyers are too bright and maybe that has to do with the amp pairing.  From what I have read about the Jotunheim, I would imagine these Beyer cans would get very bright.   The HP-A4BL may provide a more neutral character with the Beyer's.  I will post back with my experience as well as a more comprehensive review of the HP-A4BL.
 
Quick question:
 
On my portable DAPs I can use the toslink to coaxial digital adapter.  The HP-A4BL does not have a coaxial digital in but an optical in.  Can I use a toslink to optical cable like this one instead on my FiiO X5 and/or iBasso DX80 with coaxial out?
 
https://www.amazon.com/FosPower-Toslink-Digital-Connectors-Strain-Relief/dp/B00T8HWUVS/ref=sr_1_3?s=aht&ie=UTF8&qid=1485275598&sr=1-3&keywords=toslink+to+optical

Yes, that's why HPA-4BL has an optical in. Coxial and optical are basically the same, so you don't need an
extra convertor. The cable you mentionted is gonna works. make sure to select the proper input on HPA-4BL.

 

[xinghui0711]

Yes, that's why HPA-4BL has an optical in. Coxial and optical are basically the same, so you don't need an
extra convertor. The cable you mentionted is gonna works. make sure to select the proper input on HPA-4BL.

The Amazon link he had is for Optical to Mini-optical and NOT for coxial. IIRC, coaxial is NOT the same as optical. A D/A converter is needed.
Theoretically Optical is better since it blocks outside EMI and noise, which coaxial doesn't. For homeuse applications however, the difference is negeligible.

And back to topic, HP-A4BL is a great value and underrated product that Fostex forget to advertise.

 

[NoteEater]

I am not sure if my question was answered.  
 
Has anyone used the optical in on the HP-A4BL with their DAP using a mini toslink to terminated optical cable(not adapter) as opposed to the typically supplied mini toslink to coaxial adapter with coaxial digital cable?  
 
I don't want to damage my DAP or HP-A4BL if this is a problem. 

 

[likvido]

Could anybody recomend to pair HP-A4BL with ATH-MSR7?

 

[MattRG]

  Could anybody recomend to pair HP-A4BL with ATH-MSR7?

I would think that would be a good pairing.  The Fostex likes headphones with higher sensitivities (which the MSR7 has) and provides a clean, distortion free sound.  I wouldn't hesitate to match those up.

 

[soundman414]

Just got mine today. I was really looking forward to trying it out, but the firmware issue and my lack of an SDHC micro SD card has prevented me from using it. Disappointing that these are still shipping with the old firmware that doesn't work with the latest OSs. So I ordered a SDHC micro SD card and will have to wait until Tuesday to try it out.

I can say that it feels very well built with high quality parts. My only concern would be the front buttons and volume knob, which don't assert the feeling that they could take a ton of use. A few wiggle quite a bit when you push them and the volume knob has noticeable movement up and down when you turn it. So we'll see how it holds up to daily use.

 

[MattRG]

  Just got mine today. I was really looking forward to trying it out, but the firmware issue and my lack of an SDHC micro SD card has prevented me from using it. Disappointing that these are still shipping with the old firmware that doesn't work with the latest OSs. So I ordered a SDHC micro SD card and will have to wait until Tuesday to try it out.

I can say that it feels very well built with high quality parts. My only concern would be the front buttons and volume knob, which don't assert the feeling that they could take a ton of use. A few wiggle quite a bit when you push them and the volume knob has noticeable movement up and down when you turn it. So we'll see how it holds up to daily use.

What OS are you running?  I downloaded the driver directly from the Fostex website and it worked flawlessly in Windows 10 over USB.

 

[soundman414]

  What OS are you running?  I downloaded the driver directly from the Fostex website and it worked flawlessly in Windows 10 over USB.

I am running OSX. And for the Fostex to work, you have to have a SDHC Micro SD card, download the firmware from Fostex, load it on the SD card and then update the unit.
 
I don't have a SHDC Micro SD card. I have a SDXC, which isn't supported and I verified last night that it doesn't work. So I ordered a SDHC and it will be here in a day or two... Still, they should make it so that you don't have to own a particular card type. They should allow for updating it over usb, IMO.

 

[MattRG]

Ah ok, I understand.  Best of luck to you then.

 

[soundman414]

OK. So I got a SDHC card and attempted to update the firmware. But no matter what I tried, it wouldn't update. It wouldn't even write the txt file stating what firmware version is current on the unit. Anyone else had issues with updating the firmware?