# Fostex HP-A4BL (the A4 with balanced output)



## RAFA

Here the Link to the Japanese spec sheet:
  
 http://www.fostex.jp/wp/wp-content/uploads/2015/12/FOSTEX_HP-A4BL_Release.pdf
  
 http://www.fostex.jp/products/hp-a4bl/
  
 4 pole XLR-balanced output and inside a Burr-Brown PCM1792A. I believe the rest is basically the normal HP-A4.


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## Toro

more than that. It have a 12V DC power supply and higher output power than HP-A4.


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## RAFA

Ok, that is a mayor difference. The normal A4 could have been driven, by just an USB port.

Did anyone notice the headphone in the background. It is not a TH900.


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## sc0y

Anyone have ideas how or when we could get our hands on this in the US? 

I was thinking about picking up the HP-A4 to pair with the TH-x00s, but this version has some obvious appeal since it's more powerful and the balanced out seem like a nice feature even though I don't currently have a use for it.


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## derbigpr

What is that new headphone in the background? It's not a TH-X00.


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## sc0y

TH-800??? 

Maybe that's part of the motivation behind the TH-x00s -- to get public feedback and further refine their next headphone.


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## RAFA

sc0y said:


> TH-800???
> 
> Maybe that's part of the motivation behind the TH-x00s -- to get public feedback and further refine their next headphone.




Maybe there will be a balanced TH-x00 in future...


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## GrouchoMarx1933

Subbed. I'm very curious how this ends up sounding and how much it costs.


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## HiFiGuy528

merrick said:


> Subbed. I'm very curious how this ends up sounding and how much it costs.


 
  
 $399 USD


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## GrouchoMarx1933

Ooooh, tempting!


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## Frostillicus

hifiguy528 said:


> $399 USD




Any update on US release date?


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## Villy

Already on sale (below link), and for just $50 more than the unbalanced version. I'm curious though if they designed a new, fully balanced approach or rehashed the A4's design. Even if the latter it is still very tempting, hope someone posts a review soon.

http://www.proaudiostar.com/fostex-hp-a4bl-headphone-amplifier.html


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## Peti

Been looking for a USB amp/dac with balanced output and my No1 candidate so far was the Oppo HA-1. Now I just wait and see how this one will perform and looking forward for reviews/tests.


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## Frostillicus

peti said:


> Been looking for a USB amp/dac with balanced output and my No1 candidate so far was the Oppo HA-1. Now I just wait and see how this one will perform and looking forward for reviews/tests.




Wouldn't you want the original? This one added ac power (from the wall). The original hp-a4 is great, as long as you aren't trying to drive the he-6


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## Peti

As long as the original you mentioned has a balanced output I'm indeed interested...


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## Frostillicus

Sorry i think i read your post wrong. The original was usb powered, without the balanced out, the new version is ac powered with the balanced out. I thought you meant you wanted usb powered only



peti said:


> As long as the original you mentioned has a balanced output I'm indeed interested...


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## Peti

No problem. I'm looking for an AC powered DAC/amp with balanced output and usd input. Anyone have any impressions of this Fostex model yet?


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## Villy

The USB-powered model, the A4 has one upside - it is (somewhat) mobile as it can be powered off a battery pack. But it has a couple of downsides, one being quite bad - it gets fed 'dirty' power thru the USB cable which unquestionably impacts clarity (though it can be resolved by using dedicated USB signal 'washer' but it all becomes now quite expensive). Also as mentioned above, its inability to drive high impedance cans - 600 ohms are out of question altogether, 300 maybe doubtful too.
  
 A4BL on the other hand, AC-powered and balanced takes care of these two problems. If only Foster implemented a truly balanced architecture in the amp, that is separate circuits for each channel, it will be exactly what the doctor ordered. And I would think they did that, otherwise there isn't anything balanced here really, we'll see... I think I am getting one either way....and modifying my TH-X00s when they come in May to balance them with 7Ns OCC cable, that should be pretty sweeeet... then finally getting some 600 ohms.... ok, so that's my plan


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## Peti

Yep, if it's truly balanced I will get one for sure.


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## Peti

Looking nice in action!
  

  
 Also, found some factory info about this amp-dac here:
  
 http://www.fostexinternational.com/public/images/news_img/HP-A4BL.pdf
  
 Anyone knows yet if it's a truly balanced artitecture?


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## Villy

The specs on paper for the balanced terminals are great: load impedance - 16-600 ohm, THD - less than 0.04% at 1kHz, frequency response - 20Hz - 80kHz (+-3dB, 32 ohm 10mw), even for the unbalanced headphones output. Not bad, not bad. And in a meantime I revisited the whole balanced thing (being fascinated with it for years, but until just recently it was never within monetary grasp...well, for me at least) - so in short, a balanced connection needs truly balanced architecture between the components (DAC and the AMP here, even if only internally) in order to eliminate ground loop interference, which is the whole idea behind balanced - no humming or other unwanted noise artifacts.
  
 Sooooo, when we throw in the fact that this is Fostex we talk about here and the device is physically made in Japan, plus all the glowing reviews about the A4's performance (and A8 too, I'd think A4BL must eclipse the A8 given the advance of technology and materials since the latter was conceived) - I am starting to plan for real how I will convert my cans to balanced connections, all of them, not just the TH-X00.
  
 I've also been intrigued lately by going for balanced headphones in a different way, but it now seems the A4BL may be the best (and most bang-for-the-buck) way to go. Not to mention that the A4 has an opamp that when upgraded takes it to a whole new level, and my expectation is that the A4BL will share the same opamp design. Which if true, will be just unbeatable combination all around. I can't wait for someone to take a peak under the cover and break the details for us all....how long will that take....I'll stay put for now and actively plan, actively....maybe not for long, we'll see


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## Frostillicus

peti said:


> Looking nice in action!
> Is this yours? Impressions?
> 
> 
> ...


Is this yours? What are your impressions?


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## Peti

No, no. It's an image I found on the net. Should have mentioned it, my bad.


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## Jethrosang

Can be the cheapest balanced dac/amp I have ever seen, bar the matrix mini-i. I hope this catch on in head-fi, so that more reviews will follow.


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## WayTooCrazy

Dang it! Now I'm interested and I just sold my JDS Labs element, picked up a Schiit stack and I still would like to know how this turns out. I mean, I do have 15 days.


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## Vigrith

waytoocrazy said:


> Dang it! Now I'm interested and I just sold my JDS Labs element, picked up a Schiit stack and I still would like to know how this turns out. I mean, I do have 15 days.


 
  
 Yea I'm interested too. I currently own the regular A4 and I'm very happy with it, plus the design is beautiful - very intriguing that they're offering a balanced option for just an extra 50 dollars or so given how much praise balanced amps have been getting, especially considering it's even AC-powered as well rather than just USB.
  
 I could easily buy balanced cables for every headphone I use because they're all detachable and all have 70 or less ohm impedance so lack of power is not a thing (it's very rare I listen to music loud either way) so I'm left wondering how this balanced dac/amp priced at 400 would fare against say 1000~ range non-balanced options such as Resonessense Concero, Audeze Deckard or the Woo WA7 for example.


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## Erjiaihaozhe

Last month, i bought one from Amazon Japan; so i think i am qualified to post my own experience and impression with this wonderful little gadget:
 First, let's talk about its build quality; i think it is built like a tank with all aluminum body and polished front panel; however the four screws left on the top metal cover are eyesore but according to the owners of the original model A4, their presence may faciliate the replacement of OPAMP, which i have found is not so for A4-BL; more on that later. 
 Second, about its sound qualtity: i have some highly sensitive IEMs and some high and low impedance cans to pair with my A4-BL; and they pair well; the sum up, the sound of A4-BL is very neutral, resolving and spacious, not colored, more like FOSTEX adopting a reference tuning on this one, which may displease some audiophiles who have preference for a very colored sound and find the sound of A4-BL a little boring; it is noteworthy that i have only listened to the SE and have not tried the BAL OUT, which may be more powerful and euphonic judgding from the specs (300MW BAL vs 150MW SE); having read the A4 thread, i am very intrigued to try OPAMP rolling on A4-BL but my attempts to do so failed because this required the complete disasembly of the entire metiallic enclosure, taking out of the PCB and even the removal of the potentiometer, which is very tricky; however I do have a careful look at the internal PCB layout and find it quite different from that of the original A4  because FOSTEX does adopt a TRUE balanced design on this one. First I see three NJR2114Ds and two OPA2134PAs soldered onto the right corner of the PCB with a replaceable DIP version of OPA2134PA on a DIP socket, which i think is right located at the gain stage of the PCB. In addtion, what makes me think this is a truly balanced design is that channel imbalance issue frequently found on non-balanced amps is non-existent on this one. On top of that, the new type of capacictors touted by FOSTEX in its ads are actually NICHICON FG series and I do see two or three MUSES-series capacitors.
 I think what i need to do now is to find a pair of balanced headphones to see how it pairs with A4-BL; i eye for BEYER T5P 2nd GEN, but boy, what a hefty price to pay! my wallet is crying.


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## Villy

Erjiaihaozhe, this is great news, first-hand experience at last! 
	

	
	
		
		

		
			




  
 I am very interested in the balanced out, and I'd go as far as saying 'only in the balanced out' (and anyway, standard outs on balanced gear tend to be more of an afterthought). And will be great to hear impression from pairing with headphones of higher quality, where the benefit from balanced signal would be felt most. Can't wait to hear more on that.
  
 I'm also very interested in the potential for opamp rolling, in fact if it proves not possible or nearly impossible I'll likely pass on it. I truly hope this is not the case, and that a bit of soldering skills will managed to pull it off. It would be great if you can post, whenever time allows you, some pictures of the board, specifically of the OPA2134s' locations that could give us an idea of what to expect/prepare for.


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## Jethrosang

[EDIT] Wrong post. Thanks Villy!
  
 Well, meant to say if only this balanced amp/dac had 2.5mm balanced, so as to make it more flexible. Still, there is no dedicated amp with 2.5mm balanced, so I reckon no hope of seeing that, unless we use a cable adapter. 
  
 By the way, is modding a pair of headphones to hot-swap cables difficult? I am fear that the soldering, drilling and different types of wire may cause some kind of signal interference, especially on wood cup. (I am using TH-X00, by the way).


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## Villy

I would think the reason Fostex made XLR4 as the only balanced out option, is that this is a stationary device and as such the expectation is that users will be plugging full size cans rather than IEMs. Well, actually the main reason is that HP-A4BL was in fact designed to specifically match with the redesigned TH-900 MK II, which now also comes with XLR4. As for modifying cans to make them balanced - I'd say go for it, it is worth 100% assuming you have a fully balanced setup. And even if you don't, say only your amp is balanced and your DAC is not, you still will notice a differences like wider sound stage and increased detail/clarity.


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## plakat

XL4 is *much* more robust than those flimsy 2,5mm TRRS connectors... and there's absolutely no reason to use 2,5mm jacks in a desktop device.
  
 If you intend to rewire headphones for balanced I'd suggest to standardize on XL4 termination, creating adapters for other cases (single ended, dual-XLR, maybe 2,5mm TRRS etc.). But driving a low-impedance, efficient headphone like the TH-X00 balanced won't buy you anything except some time with a soldering iron and the satisfaction of modifying them yourselves...


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## Villy

> ...driving a low-impedance, efficient headphone like the TH-X00 balanced won't buy you anything...


 
  
 I tend to disagree. It is only my humble take on it based on my own modding experience, but at Fostex apparently they also believe there is something to be gained by going balanced considering that the A4BL was created specifically for 900 MKII.


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## plakat

villy said:


> I tend to disagree. It is only my humble take on it based on my own modding experience, but at Fostex apparently they also believe there is something to be gained by going balanced considering that the A4BL was created specifically for 900 MKII.


 

 To me its in most cases an unwarranted expense (not the modification of a headphone, which can be a fun project in itself, but the additional electronics of a balanced amp). There are statements by people like someone at Benchmark (I think their technical chief architect or something like that) or Rob Watts of Chord speaking up for single-ended amp designs. I don't know how your level of knowledge on electronics design is, so I don't want to repeat potentially obvious points you already know anyway.
  
 Overall I think offering balanced amps is more of giving customers what they call for (much like DSD) than offering an alternative that in most cases is better than single-ended (which balanced is not). The A4BL is still within power territory of a single-ended design, so not even the 'enormous power' argument counts in this case.
  
 I don't think the A4BL was targeting the TH900mk2 but the TH610 (which will have removable cables as well). Which leads me to the conclusion that there might be something like an A8BL coming...


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## Villy

I don't want to engage in what Fostex meant or didn't mean by it, but they debuted 900 MKII with a optional balanced cable and A4BL together at NAMM 2016 and that to me says a lot (and not just to me really). While 610 is still just a teaser.


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## plakat

villy said:


> I don't want to engage in what Fostex meant or didn't mean by it, but they debuted 900 MKII with a optional balanced cable and A4BL together at NAMM 2016 and that to me says a lot (and not just to me really). While 610 is still just a teaser.




... Which was used in the background of the first photos of the A4BL.
I think they'll keep the two model setup just like with A4/TH600 and A8/TH900, would be very surprising to see the A4BL replace the A8. But never mind, they won't deny selling a A4 to pair with a TH900 of course, and I'm sure the combination will work just fine.


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## Jethrosang

Well, most IEMs are terminated in 2.5mm or 3.5mm balanced, so adding another output for this would be nice.
  
 And I guess the thing about balanced output is down to the architect of the circuits, they might emphasise the performance of the balanced output, or just add it for the sake of having it. I think in Fostex case, even if they only have 1 dac, their amp is balanced out (I think it is true balanced, not just the matter of rewiring it).


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## Villy

> ... Which was used in the background of the first photos of the A4BL...


 
  
Fostex at NAMM 2016


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## plakat

villy said:


> Fostex at NAMM 2016




And long before that:
http://www.head-fi.org/t/792916/fostex-hp-a4bl-the-a4-with-balanced-output


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## ptolemy2k6

How would one introduce balanced source to utilize balanced out? especially from usb out?


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## Villy

ptolemy2k6 said:


> How would one introduce balanced source to utilize balanced out? especially from usb out?


 
  
 I don't quite understand the question, 'introduce balanced source' in what sense? Do you mean how will the data stream coming from the USB will find its way thru the components and end up being balanced signal into the headphones, is that it?


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## ptolemy2k6

villy said:


> I don't quite understand the question, 'introduce balanced source' in what sense? Do you mean how will the data stream coming from the USB will find its way thru the components and end up being balanced signal into the headphones, is that it?


 
 hi
  
 no. i meant. how would one get balanced input in order to use balanced out. i assume that if you use usb or rca or toslink in, it's not in balanced form?


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## Villy

OK, it seems you are looking for an overview of the process and I'll give it a try. In fact since I'm not an engineer my overview may actually come to be quite understandable 
	

	
	
		
		

		
			





 
  
 So the data comes from the music player (computer, CD, digital media player, etc.) into the DAC as a digital stream (the computer bits you know, 1s and 0s like in 110001101). The DAC then utilizes a computing type of chip that is specifically programmed to recognize and convert the digital stream into analog audio signal. That analog signal from the converter chip then is passed to the DACs circuitry which in fully balanced DACs has physically separate paths for the RCAs and the XLRs on its way out. The signal going thru and out from the XLR side of the circuitry is different in many ways, from being fully isolated from ground interference/noise to being more twice as powerful. The amplifier on the receiving end must also have fully balanced design like the DAC to take advantage of the signal. And finally the balanced signal must be passed from the amplifier to the headphones thru a balanced output, where each channel has its own separate wires, 2 of them, one carrying '+' and carrying '-' signal, and none of the wires is shared with the other channel. In standard-ended output, the two channels have separate '+' signal coming to them and they share a common ground ('-') wire. 
  
 In a single unit design such as HP-4ABL, both the DAC and Amp circuitry share the same box and signal transfer from to other happens inside. This design has the advantage of eliminating some conversion steps. On the downside, in integrated devices corners are usually cut to make the box affordable, otherwise it would be no less expensive than getting two separate units (like Oppo HA-1 and similar combo units).
  
 Hope that makes any sense.


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## ptolemy2k6

villy said:


> OK, it seems you are looking for an overview of the process and I'll give it a try. In fact since I'm not an engineer my overview may actually come to be quite understandable
> 
> 
> 
> ...


 
 hi
  
 thanks for the detailed explanation but alas it's lost on me hehe. my q i think was simpler: if i connect usb out to computer and plugin into balanced port, instead of 1/4", will I get a balanced connection (lcd-3 have both balanced and 1/4" connection, that's why I am asking).
  
 thank yiou


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## Villy

If you connect your computer, or whatever digital device that will play the music, to HP-4ABL, then you connect your headphones to the balanced headphone output, the XLR4 output, and the headphones' cable is truly balanced (that is, the cable has 4 separate wires, 2 per channel, and not a standard 3-wire cable that has been terminated with XLR), then yes your headphones will receive fully balanced signal.
  
 I think we got it covered this time, right?


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## ptolemy2k6

you nailed it. thank you!


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## ch1n4

erjiaihaozhe said:


> Last month, i bought one from Amazon Japan; so i think i am qualified to post my own experience and impression with this wonderful little gadget:
> First, let's talk about its build quality; i think it is built like a tank with all aluminum body and polished front panel; however the four screws left on the top metal cover are eyesore but according to the owners of the original model A4, their presence may faciliate the replacement of OPAMP, which i have found is not so for A4-BL; more on that later.
> Second, about its sound qualtity: i have some highly sensitive IEMs and some high and low impedance cans to pair with my A4-BL; and they pair well; the sum up, the sound of A4-BL is very neutral, resolving and spacious, not colored, more like FOSTEX adopting a reference tuning on this one, which may displease some audiophiles who have preference for a very colored sound and find the sound of A4-BL a little boring; it is noteworthy that i have only listened to the SE and have not tried the BAL OUT, which may be more powerful and euphonic judgding from the specs (300MW BAL vs 150MW SE); having read the A4 thread, i am very intrigued to try OPAMP rolling on A4-BL but my attempts to do so failed because this required the complete disasembly of the entire metiallic enclosure, taking out of the PCB and even the removal of the potentiometer, which is very tricky; however I do have a careful look at the internal PCB layout and find it quite different from that of the original A4  because FOSTEX does adopt a TRUE balanced design on this one. First I see three NJR2114Ds and two OPA2134PAs soldered onto the right corner of the PCB with a replaceable DIP version of OPA2134PA on a DIP socket, which i think is right located at the gain stage of the PCB. In addtion, what makes me think this is a truly balanced design is that channel imbalance issue frequently found on non-balanced amps is non-existent on this one. On top of that, the new type of capacictors touted by FOSTEX in its ads are actually NICHICON FG series and I do see two or three MUSES-series capacitors.
> I think what i need to do now is to find a pair of balanced headphones to see how it pairs with A4-BL; i eye for BEYER T5P 2nd GEN, but boy, what a hefty price to pay! my wallet is crying.


 

 thanks for your impressions. Did you test it with high impedance phones? I am wondering if it could drive a Sennheiser HD 600/650 in balanced mode.
 is it already available outside japan? couldn't find any reviews...


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## lbbef

I've been thinking of getting the HP-A4BL for quite some time.

I have the HP-A4 and use it exclusively as a DAC into my AT-HA22TUBE. I'm feeding it clean power from a linear power supply into a USB conditioner which also separates the data and power lines. And it simply sounds amazing.

But the HP-A4BL with the upgraded components as well as the ability to feed it dc power directly is tempting. Not to mention the quad rate DSD support (original HP-A4 only double rate). If they had it with a dual PCM1792A then it'll be perfect. (PCM1792A is my favorite DAC chip)

But I guess all this has to wait since I just recently upgraded the power and cables in my setup.


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## lbbef

That aside. There seems to be a minor mismatch in specs between the Fostex international site and Fostex JP site. The international site lists 300mW into 32ohms unbalanced. The JP site lists 150mW into 32ohms unbalanced.


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## Villy

*B&H* expects to have it available in stock by May 20th, so maybe within a month we'll have some impression and details from more responsive members. I am still interested, though it is not likely I'll make a move until I read some solid reviews. And even then it is unlikely, my current setup is pretty hard to beat but I'll keep open mind (and ears  about it.


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## Uzuzu

rafa said:


> Here the Link to the Japanese spec sheet:
> 
> http://www.fostex.jp/wp/wp-content/uploads/2015/12/FOSTEX_HP-A4BL_Release.pdf
> 
> ...


 
 I believe that headphone is the TH-600 mk 2, compliment to the recent TH-900 mk 2 released with disconnectable cables. And they ditched the magnesium cups for wood.


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## tp147

Hello altogether,
  
 has anyone experience with this amp paired with Hifiman HE400, 500, 560, 600 or Audeze LCD 2 or 3 and has the amp the capability to drive those planners proper?
 I would suggest it is able to drive Fostexs own T50RP or the more expensive TH500RP, isn't it?
  
 BTW: If this amp has a real symmetric design, why doesn't it have a symmetric balanced line out with XLRs?
  
 Thanks & cheers
  
 Thorsten


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## Slow_aetk

I wonder if the DAC part of it is also balanced? Which is the same as asking if the PCM1792A is a 4 channels or 2 channels?
 This amp is very interesting and not expensive if it is a real and full balanced dac/amp.
  
 Anybody?


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## Villy

I'm not aware of it being sold outside of Japan, some people had it shipped from there but I doubt many enough to have meaningful impressions, let alone experience with planars. I'm eager to hear some feedback too, and will indeed buy it once available in the states.


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## Slow_aetk

villy said:


> I'm not aware of it being sold outside of Japan, some people had it shipped from there but I doubt many enough to have meaningful impressions, let alone experience with planars. I'm eager to hear some feedback too, and will indeed buy it once available in the states.


 
 It is available in Europe or at least in Switzerland. My preferred reseller has one in stock. To buy or not to buy...


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## WayTooCrazy

slow_aetk said:


> It is available in Europe or at least in Switzerland. My preferred reseller has one in stock. To buy or not to buy...


 

 Buy, test, give impressions, return if you don't like.


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## Villy

I have put a pre-order with B&H here in the US, at $399 - don't know what it costs in EU, but getting DSD DAC with balanced amp from Fostex at this price, in a good-looking package at this price is a no-brainer. Not to mention the potential ability to swap opamps, so yes just get it and report back.


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## Shogster

Is it worh it getting this version if im not going to use the balanced out? Im going to use it with the Purplehearts.


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## tp147

I Germany it is around 500 EUR (550 USD), but its balanced output is only for headphones, line out is only RCA unbalanced.
  
 Please give us your impressions.
  
 Thanks & cheers
  
 Thorsten


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## Treeko

Hey guys is it 300mW unbalanced or balanced? And from an owners perspective how is it fairing? 
Cheers in advance!


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## chowyeung

Excuse me. May someone confirm whether the rear RCA outputs are fixed or variable? Can HP-A4BL be used also as a volume controller for active speakers?
 Thanks in advance.


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## Shogster

chowyeung said:


> Excuse me. May someone confirm whether the rear RCA outputs are fixed or variable? Can HP-A4BL be used also as a volume controller for active speakers?
> Thanks in advance.


Yes, it will control the volume of your speakers. There is a switch on the front for rca's or headphones.


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## chowyeung

shogster said:


> Yes, it will control the volume of your speakers. There is a switch on the front for rca's or headphones.


 
  
 Thanks for your reply!
  
 That's great! I now have no reason not buying it!
 Cheers


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## Emcdade

HPA4BL for $399

HPA8 refurb for $599

Which one would you guys recommend to drive a Denon D7000?


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## leepc

received my Fostex A4BL from Proaudiostar (ordered over 4 months ago.. almost forgot it). 
 The built quality is nice. made in Japan. Thought m9xx and Teac UD-301 feel sturdier. 
  
 Pairing with HD650 and T90, the first impression is mellow, warm sound but a little less high, less dynamics, less details, less separation than both m9xx and Teac.
  
 But after couple hours listening, I start enjoying its sound signature. A4BL delivers bigger warmer meatier thicker vocal which makes me "feel" the singers closer.Even with less details and less dynamics at the instruments, somehow I feel less cold digital but a little more warm analog sound.... Just my two cents


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## Jethrosang

leepc said:


> received my Fostex A4BL from Proaudiostar (ordered over 4 months ago.. almost forgot it).
> The built quality is nice. made in Japan. Thought m9xx and Teac UD-301 feel sturdier.
> 
> Pairing with HD650 and T90, the first impression is mellow, warm sound but a little less high, less dynamics, less details, less separation than both m9xx and Teac.
> ...


 
 So, something akin to tube (lite version, I suppose)? By the way, thanks for that impression. Do you use it through the balanced output? Have you tried single ended as well?


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## davidmthekidd

Would this dac/amp drive the HD650? Wonder if these would be better than my current Apogee Groove. Thanks


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## ptolemy2k6

davidmthekidd said:


> Would this dac/amp drive the HD650? Wonder if these would be better than my current Apogee Groove. Thanks


 
 it drives lcd-3 just fine, so it should drive hd650 easily.  it's a very good amp, IMO. very good sound, little warmish but I like warm.
  
 it's also very small compare to other desktop ones.


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## davidmthekidd

ptolemy2k6 said:


> it drives lcd-3 just fine, so it should drive hd650 easily.  it's a very good amp, IMO. very good sound, little warmish but I like warm.
> 
> it's also very small compare to other desktop ones.




Good. The Apogee Groove handle the HD650 with no problem.i would like to connect powered speakers as well which is why I am considering the fostex.


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## ptolemy2k6

davidmthekidd said:


> Good. The Apogee Groove handle the HD650 with no problem.i would like to connect powered speakers as well which is why I am considering the fostex.


 
 it would be a good choice IMO. i also have fostex powering powered speakers and taking input from a tablet


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## Vigrith

davidmthekidd said:


> Would this dac/amp drive the HD650? Wonder if these would be better than my current Apogee Groove. Thanks


 
  
 For this price I recommend the Jotunheim over the A4-BL. I have both and in my eyes there's really no contest, though if at all relevant I'm quite fond of the DAC in the A4, it's very musical sounding, I just think the amplification side of things is lacking hard compared to the Schiit.
  
 Definitely not a bad unit though, especially if you want an even more compact footprint, but the Jotun's synergy with the 650 is (in my opinion, as well as many others') off the charts, with the Fostex they are just what you'd expect them to be.


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## davidmthekidd

vigrith said:


> For this price I recommend the Jotunheim over the A4-BL. I have both and in my eyes there's really no contest, though if at all relevant I'm quite fond of the DAC in the A4, it's very musical sounding, I just think the amplification side of things is lacking hard compared to the Schiit.
> 
> Definitely not a bad unit though, especially if you want an even more compact footprint, but the Jotun's synergy with the 650 is (in my opinion, as well as many others') off the charts, with the Fostex they are just what you'd expect them to be.




The Schiit seems huge. I have a tiny desk. Thanks for your opinion tho.


----------



## davidmthekidd

very stupid question here, but what is the real application of the following? how would this impact my sound?
  
(Digital Filter selecting Roll-Off characteristics and Cut-off frequencies)


----------



## Naim.F.C

Read some impressions from someone who tested both this and the Jotunheim on some other forum, and he mentioned that with the Ether C's he actually preferred the HP-A4BL. Now it's got me wondering. I will be using whatever Amp/Dac I next buy (as a secondary system) with mostly the Sony MDR-Z1R (which is a fairly warm, bass heavy can), but also with the Beyerdynamic T1's and Sennheiser HD800's (the complete opposite), so I'm in a bit of a dilemma as to which would be better suited to me. I guess a proper Jotunheim vs HP-A4BL comparison, with a range of cans is needed lol.


----------



## Naim.F.C

*This thing rocks.*
  
 So I ended up purchasing this little baby out of sheer curiosity. I needed a bedside Amp/Dac set up, and as touched upon above, was contemplating between another O2+ODAC, a JDS The Element, Schiit Jotunheim, and this Fostex HP-A4BL. The Fostex was the cheapest to include a balanced XLR output on top of an optical out (for connecting to the PS4 Pro/PS4 or Xbox One), so I thought why not. You can find it from between £360 and £375, which makes it fairly solid value. It's only $350 in the US, which is even better value for money.

 The Schiit Jotunheim was the next cheapest attractive alternative to include balanced out, but doesn't have an optical in, and is also £90 more expensive at todays exchange rate (including shipping), but not including taxes (a possible 20% VAT on top). Granted specs wise it's a lot more powerful.

*Initial impressions.*

 After some brief testing with the HP-A4BL yesterday, I cannot _believe_ this Dac/Amp combo is not more popular. Why this thread is only on page 5, whilst the Jotunheim's is on page 177, I'm not quite sure.
  
 In terms of sound quality, it is every bit as competent as the Violectric V200+Rein Audio X-DAC, the X-DAC+O2 and the O2+ODAC. There are miniscule differences between some of them, depending on the connection type and combination set up used, but it's generally a case of very minor, oft insignificant, other times nonexistent one's that don't massively sway things either way.
  
*Importance of volume matched A/B'ing, including blind.*

 Essentially the HP-A4BL on it's own (internal DAC and amp) via USB, sounds _exactly_ the same as the Rein Audio X-DAC + Objective 2 combo via Optical, which is one of my fave combinations that I own or have tested (including versus other much more expensive gear I either own, or no longer own). And for the record, I A/B blind tested multiple times (with the help of my wife), and volume matched via mic readings before hand. Before I did that, placebo was well and truly kicking in (including when comparing the two different digital filter modes).
  
 The mind is a powerful thing. Trust me, until you've persistently A/B tested with extreme analytical concentration, with as close to perfectly volume matched set up's as possible, do not think you can accurately gauge sonic differences. Simply put, you can't. Even a 5-10% difference in volume between set ups can make _all_ the difference.
  
*USB vs Optical?*

 Another good thing about the HP-A4BL is that out of my Macbook Pro Retina, just as with my X-DAC, there does seem to be a very slight difference in signature between Optical and USB (based on rudimentary preliminary testing), which is good because it allows me to switch between neutral and ever so slightly warm. 

*Power.*

 One slight negative however is that the HP-A4BL doesn't quite have the same amount of power as my O2, nor my Violectric V200. That said, it still has more than enough for my use, and is sufficient enough to power the MDR-Z1R's, HD800's and T1's. With the Z1R's I don't go need to beyond half volume on low gain, and with the other two, I don't even get to half way on the volume knob in high gain, In other words, there's more than enough juice for real world use.

*For now.*

 I'll go in to more detail in my subsequent review, including comparisons with all the different combos I've compared, but for now I'd like to do more tests, including more blind A/B one's. I haven't even gotten around to testing the balanced out yet, which I'm looking forward to.

 In conclusion ahead of my review though, just go buy this amp/dac. For the money you simply cannot go wrong. 

*Pic.*

 Here's a cheeky mobile snap. Apologies for the ugly white cardboard box, just waiting for my new Oak bedside draw to be delivered!


----------



## Aleo

> *Power.*
> 
> One slight negative however is that the HP-A4BL doesn't quite have the same amount of power as my O2 (which I believe JDS tweaked specifically for use with my T1's) nor my Violectric V200, though the gain does seem to make more of a difference than it does with the O2. That said, it still has more than enough for my use, and is sufficient enough to power the MDR-Z1R's, HD800's and T1's. With the Z1R's I don't go need to beyond half volume on low gain, and with the other two, I don't even get to half way on the volume knob in high gain, In other words, there's more than enough juice for real world use.


 
 Wait, so this thing has less power than the O2? Have you tried this thing with XLR output yet to see if there's more power there?


----------



## Naim.F.C

aleo said:


> Wait, so this thing has less power than the O2? Have you tried this thing with XLR output yet to see if there's more power there?


 
  
 Yes. At least based on how far I have to turn the volume knob to volume match. I've not maxed out the volume dial on either, nor do I intend to. From rough memory, with the MDR-Z1R's I turn the volume knob around 30-35% of the way on the O2, and roughly 40-45% of the way on the HP-A4BL, that's unbalanced, both in low gain. Any more than that is too loud and uncomfortable for my personal preferences. With the T1's, it's a similar positioning for both but in high gain, and similar again for the HD800's, if anything a fraction lower than needed for the T1's.

 I have not tested balanced on the HP-A4BL yet (waiting for my balanced cables to come through), but according to their site specs, balanced essentially offers twice the power output.


----------



## davidmthekidd

I also own this Dac/amp, in conjunction with the hifiman 400i, so far I love everything about it. You can't go wrong for the price. I'll try to do a video review in the coming weeks since I can't find no reviews on this product. Others are welcome..... 



naim.f.c said:


> *This thing rocks.*
> 
> So I ended up purchasing this little baby out of sheer curiosity. I needed a bedside Amp/Dac set up, and as touched upon above, was contemplating between another O2+ODAC, a JDS The Element, Schiit Jotunheim, and this Fostex HP-A4BL. The Fostex was the cheapest to include a balanced XLR output on top of an optical out (for connecting to the PS4 Pro/PS4 or Xbox One), so I thought why not. You can find it from between £360 and £375, which makes it fairly solid value. It's only $350 in the US, which is even better value for money.
> 
> ...


----------



## davidmthekidd

Whenever you get your balanced cables let me know, I am interested in this option aswell.


----------



## davidmthekidd

Has anyone tried the set of Balanced Cables yet on the HP-A4BL?


----------



## Naim.F.C

davidmthekidd said:


> Has anyone tried the set of Balanced Cables yet on the HP-A4BL?




I have, but before I post more impressions I'm just waiting on one more set of balanced cables to turn up, so I can determine whether the difference I'm hearing is the cable, or the output from the amp/DAC itself. Presumably it should be through the device itself and not the cable. All I can say for now is that after multiple A/B comparisons, I do feel like the balanced out with my current cables, sounds ever so slightly warmer, with the mids being a touch more forward. However I don't want to confirm that until I've done more volume matched testing, including blind A/Bing. 

I should also add, the balanced out delivers more power than the single ended. Not by a huge degree, but an appreciable one, perhaps 20%ish difference on the volume pot.


----------



## Aeromarine

I am getting this in the new year, will share my impression here.


----------



## powei0925

Recently obtained the Schiit Jotunheim, really pleased with the quality of the unit. DAC and amp power upgrade is obvious over Fiio e07k. On HE400i, bass is even more immediate, vocals are warm, and soundstage just opens up. Very pretty, but has significant heat output. I'm someone who just hates heat output problems, so I'm considering Fostex HP-A4BL's cool head over the power and feature of the Jot. Can someone compare the "frequency response" of these two?


----------



## powei0925

How does the power of the amp compare between jot and a4bl?


----------



## obsidyen

sub


----------



## Aeromarine

powei0925 said:


> How does the power of the amp compare between jot and a4bl?




I don't really think HP-A4BL would compare to Jot! At 300mw (32ohm) is already 3x more power then HP-A4 USB powered model. Jot is a monster compare to A4BL


----------



## powei0925

aeromarine said:


> I don't really think HP-A4BL would compare to Jot! At 300mw (32ohm) is already 3x more power then HP-A4 USB powered model. Jot is a monster compare to A4BL


 
 Indeed i would agree that the HP-A4BL would not compare to jot in its amp, the question is how much. HP-A4 is usb powered, HP-A4BL has 12V/1.5A DC, therefore it can be assumed to have more powerful amp than HP-A4. The problem is I already have a PC in the vicinity, I really don't need another heater in my room. The HP-A4BL has features (Phones/RCA button) that I might use more commonly than the Jot (balanced input). If HP-A4BL has an amp somewhat comparable to Jot, I would prefer to have a cooler room back.


----------



## Aeromarine

I am in the same shoe as you, been debating to myself going after a mid/low range desktop amp/dac and pair an other headphone (i.e. Final Sonorous III) with a dragonfly red as a temp set-up for all day use, but I am thinking to get a mojo as mobile endgame setup, and use mojo as Dac + higher end desktop amp moving to my end game setup. I really don't want to going down the rabbit hole too deep...


----------



## obsidyen

aeromarine said:


> I don't really think HP-A4BL would compare to Jot! At 300mw (32ohm) is already 3x more power then HP-A4 USB powered model. Jot is a monster compare to A4BL


 

 It is more powerful but does it sound better? I've seen reports hat said Jot has treble haze and harshness.


----------



## powei0925

aeromarine said:


> I am in the same shoe as you, been debating to myself going after a mid/low range desktop amp/dac and pair an other headphone (i.e. Final Sonorous III) with a dragonfly red as a temp set-up for all day use, but I am thinking to get a mojo as mobile endgame setup, and use mojo as Dac + higher end desktop amp moving to my end game setup. I really don't want to going down the rabbit hole too deep...


 
 I've not heard the mojo, but if you're going for portable amp, do check out the Oppo HA-2SE before buying the mojo. I've heard many saying the Oppo HA-2SE is much better proposition for its price and features. When I inevitably get a portable dac/amp, that's probably my purchase. For me, I've already known for a long time that I'm the guy that tripped over the audiophile rabbit hole, plummeted straight down the tunnel without a scratch only to land on my keys. So I'm trying to avoid purchasing anything unnecessary, and instead focusing on saving up for that endgame setup.
  
  


obsidyen said:


> It is more powerful but does it sound better? I've seen reports hat said Jot has treble haze and harshness.


 
 Is that a "dac-centric" issue? Compared to which units of same price range?


----------



## MattRG

I just ordered one of these from Amazon using some Gift cards I had saved up.  I've done a ton of research over the last couple of days on amp/DAC combos and the HP-A4BL seems like the right combination of features, aesthetics (yes, how it looks on my desk is important to me) and price.
  
 Will report back once I've had a few days worth of listening under my belt.


----------



## xinghui0711

I have checked the output power of A4BL: it's 150mW or higher for 32ohm unbalanced and 300mW balanced output. The PCB board looks well designed from a glance. For me the optical input, features, and Japan Made are the selling points. If you are using super hard to drive headphones, A4BL is probably not ideal.


----------



## Aeromarine

do you think if A4BL can drive 400i? Or dt880 250ohm


----------



## xinghui0711

aeromarine said:


> do you think if A4BL can drive 400i? Or dt880 250ohm




Those shouldn't be a problem.


----------



## MattRG

The original seller on Amazon cancelled my order last night.  :>(
  
 Re-ordered this morning through another seller on Amazon but now my estimated arrival date is sometime during the first week in January.  Oh well, good things are worth have some patience.


----------



## MattRG

According to Amazon my HP-A4BL was delivered today.  That was faster than expected!  The long weekend and New Year's break should give me an opportunity to get well acquainted with it this weekend.
  
 One thing seems to be certain, this particular device is really flying under the radar.  There doesn't seem to be much buzz about it and I don't think I've found any reviews online either.  The HP-A3 was well regarded and well received but it seems like there might be a lot more competition in the under $400 amp/DAC market than there was a few years ago when it launched.
  
 "Made in Japan" + Balanced XLR output at this price point should be a strong selling feature so maybe the device just needs more publicity.


----------



## xinghui0711

mattrg said:


> According to Amazon my HP-A4BL was delivered today.  That was faster than expected!  The long weekend and New Year's break should give me an opportunity to get well acquainted with it this weekend.
> 
> One thing seems to be certain, this particular device is really flying under the radar.  There doesn't seem to be much buzz about it and I don't think I've found any reviews online either.  The HP-A3 was well regarded and well received but it seems like there might be a lot more competition in the under $400 amp/DAC market than there was a few years ago when it launched.
> 
> "Made in Japan" + Balanced XLR output at this price point should be a strong selling feature so maybe the device just needs more publicity.


 
 Buying from Japan the price is about 348 USD, which is hard to beat. TBH there isn't much competition and A4BL does have a spot.


----------



## MattRG

Well, I wish Fostex much success with the HP-A4BL.  It's certainly satisfying my needs and looks great on my desk while doing so.  I'm itching to match a set of cans with an actual Fostex driver to it but as I just spent $600+ for the HP-A4BL and my new Meze 99 Classics I am holding off on new audio gear purchases for awhile in the name of domestic tranquility.


----------



## obsidyen

I will have Fostex TH-610 in a few days, I'm wondering if I should get this amp or something more powerful. Apparently Chord Electronics is going to announce some new stuff as well...


----------



## MattRG

The HP-A4BL would do a great job with the 25 ohm TH-610's.  Then again, so would anything by Chord, albeit at a higher price.  The Fostex gets you enough power to get the job done and a great feature set at an excellent price.


----------



## soundman414

Has anyone tried the HP-A4BL with at least a couple of IEMs?

 Low noise floor, even when it's turned up?

 Good channel balance at low volumes?

 I've been contemplating getting this as a replacement for my JDS C5D, I'd love to have a volume knob to quickly turn down the music as I listen mostly at work and sometimes get bugged frequently and need to mute the volume quick.


----------



## MattRG

I haven't but I can certainly plug in my Sony EX650 T's tonight when I get home and give them a go to see what I think and report back.  Stay tuned.


----------



## MattRG

soundman414 said:


> Has anyone tried the HP-A4BL with at least a couple of IEMs?
> 
> Low noise floor, even when it's turned up?
> 
> ...


 
 Good news.  The HP-A4BL displays no hiss even at max volume with my IEM's plugged in.  Also no channel imbalance at low volumes.  It's just smooth, silky sound with a quiet, quiet background.


----------



## Limu Shirin

mattrg said:


> Good news.  The HP-A4BL displays no hiss even at max volume with my IEM's plugged in.  Also no channel imbalance at low volumes.  It's just smooth, silky sound with a quiet, quiet background.


 

 Hi, what IEMs do you use with hpa-4bl?
 I have the Shure SE846, you think they pair well (noise floor, sound quality)
 thanks


----------



## MattRG

Sony MDR - EX650 T is my every day pair of IEM's.  I have no experience with the Shure SE846's so I can't speak to those but it does a good job with my Sony MA900's (Open back 12ohm)  Meze 99 Classics (Closed back 32ohm) and the Sony EX650 (IEM) so it is a versatile unit with both low and high gain settings.


----------



## badlucy999

http://review.kakaku.com/review/K0000840187/#tab
 ・バランス接続(本機は擬似バランス、GND分離とのこと):HD650の純正ケーブルを改造して使用(XLR4化とXLR4->標準プラグ作成) まず、同じボリュームでもバランスの方が音が大きい。中高域がクリアになり、かつ全域でメリハリが出たと感じる。事前に他人のレビューを参考にしてたのでプラセボを否定できませんが…。いずれにせよ、HD650を敢えてアンバランス接続することは今後は無いでしょう。GOOGLE>>>>Balanced connection (This machine has pseudo balance, GND separation): Use the original cable of HD650 remodeled (XLR 4 and XLR 4 -> Create standard plug) First of all, balanced sound is bigger even with the same volume. I feel that the middle to high range has become clearer and the sharpness has come out across the whole area. I could not deny a placebo because I was referring to the reviews of others in advance. In any case, there is no way to dare to unbalance the HD 650 in the future.
 ps> thats a cool web.even use google translate still lots of fun


----------



## Limu Shirin

mattrg said:


> Sony MDR - EX650 T is my every day pair of IEM's.  I have no experience with the Shure SE846's so I can't speak to those but it does a good job with my Sony MA900's (Open back 12ohm)  Meze 99 Classics (Closed back 32ohm) and the Sony EX650 (IEM) so it is a versatile unit with both low and high gain settings.


 

 I jst received the HPA-4Bl and confirm that it's the cleanest dac/amp I tried with Shure SE846.
 No noise floor, no EMI interference, no nothing.


----------



## Razornova

How would these compare with the Audio-gd NFB-11? NFB-11 is about $100 less....


----------



## Naim.F.C

razornova said:


> How would these compare with the Audio-gd NFB-11? NFB-11 is about $100 less....


 
  
 They compare excellently with mostly anything. Don't let the price detract you from thinking they're any less capable. Ok so the power output isn't as high as some competing models, but they're pretty much capable enough to power basically anything at safe listening levels. I use them to power my T1's, HD800's and Z1R's, and there's more than enough juice for me.
  
 Ultimately though, the noise floor is zilch, and the audio quality is superb. If you asked me which was better out of my £380 HP-A4BL, my £690 Violectric V200 and my £230 O2+ODAC, I wouldn't say either. They're equally as capable as each other, but have different strengths and qualities. Audio quality wise the V200 is a touch coloured which makes it fun to use, the Fostex and O2 are essentially dead neutral (at least when the HP-A4BP is connected via USB). The V200 is the most powerful. The O2 the cheapest but least convenient and worst looking, and the HP-A4BL isn't nearly as powerful as the V200, but is still powerful enough for me, whilst also being small, nice looking, relatively affordable and feature rich, thanks to both optical and balanced options (I'm predominantly using balanced now, with both my Z1R's and HD800's). 
  
 If anything, the most annoying thing about the HP-A4BL is that it doesn't have a power button lol. I dislike having to seek out the ideal volume level each time I use it, because the volume knob is the power on. I wish I could just leave the volume knob at a certain turn, and just have a switch to turn it on and off.


----------



## Limu Shirin

razornova said:


> How would these compare with the Audio-gd NFB-11? NFB-11 is about $100 less....


 
 I don't know about NFB-11, but the Fostex is made in Japan, and has a very low output impedence.
 So low that even Shure SE846 doesn't pick any hiss or EMI noise from PC. It's much smaller
 and lighter than NFB-11 and has a balanced output as well. So if you're using super sensetive cans
 or IEM's go with the fostex. It also can power T50RP MK3s on high gain pretty well.
 Also check the NFB-11 thread, will help.


----------



## Razornova

limu shirin said:


> I don't know about NFB-11, but the Fostex is made in Japan, and has a very low output impedence.
> So low that even Shure SE846 doesn't pick any hiss or EMI noise from PC. It's much smaller
> and lighter than NFB-11 and has a balanced output as well. So if you're using super sensetive cans
> or IEM's go with the fostex. It also can power T50RP MK3s on high gain pretty well.
> Also check the NFB-11 thread, will help.


 
  
  


naim.f.c said:


> They compare excellently with mostly anything. Don't let the price detract you from thinking they're any less capable. Ok so the power output isn't as high as some competing models, but they're pretty much capable enough to power basically anything at safe listening levels. I use them to power my T1's, HD800's and Z1R's, and there's more than enough juice for me.
> 
> Ultimately though, the noise floor is zilch, and the audio quality is superb. If you asked me which was better out of my £380 HP-A4BL, my £690 Violectric V200 and my £230 O2+ODAC, I wouldn't say either. They're equally as capable as each other, but have different strengths and qualities. Audio quality wise the V200 is a touch coloured which makes it fun to use, the Fostex and O2 are essentially dead neutral (at least when the HP-A4BP is connected via USB). The V200 is the most powerful. The O2 the cheapest but least convenient and worst looking, and the HP-A4BL isn't nearly as powerful as the V200, but is still powerful enough for me, whilst also being small, nice looking, relatively affordable and feature rich, thanks to both optical and balanced options (I'm predominantly using balanced now, with both my Z1R's and HD800's).
> 
> If anything, the most annoying thing about the HP-A4BL is that it doesn't have a power button lol. I dislike having to seek out the ideal volume level each time I use it, because the volume knob is the power on. I wish I could just leave the volume knob at a certain turn, and just have a switch to turn it on and off.


 
  
 Thanks for the replies guys. Just afraid I might upgrade to something hard to drive in the future... NFB-11 has lots of power. Btw for those who do not need balanced, there's a really good deal for the unbalanced variant, HP-A4, on amazon.jp.
  
 https://www.amazon.co.jp/FOSTEX-%E3%83%98%E3%83%83%E3%83%89%E3%83%9B%E3%83%B3%E3%82%A2%E3%83%B3%E3%83%97-A%E5%A4%89%E6%8F%9B%E5%99%A8%E5%86%85%E8%94%B5-%E3%83%8F%E3%82%A4%E3%83%AC%E3%82%BE%E5%AF%BE%E5%BF%9C-HP-A4/dp/B00G97FG5W/ref=sr_1_1?ie=UTF8&qid=1484414112&sr=8-1&keywords=hp-a4


----------



## Limu Shirin

razornova said:


> Thanks for the replies guys. Just afraid I might upgrade to something hard to drive in the future... NFB-11 has lots of power. Btw for those who do not need balanced, there's a really good deal for the unbalanced variant, HP-A4, on amazon.jp.
> 
> https://www.amazon.co.jp/FOSTEX-%E3%83%98%E3%83%83%E3%83%89%E3%83%9B%E3%83%B3%E3%82%A2%E3%83%B3%E3%83%97-A%E5%A4%89%E6%8F%9B%E5%99%A8%E5%86%85%E8%94%B5-%E3%83%8F%E3%82%A4%E3%83%AC%E3%82%BE%E5%AF%BE%E5%BF%9C-HP-A4/dp/B00G97FG5W/ref=sr_1_1?ie=UTF8&qid=1484414112&sr=8-1&keywords=hp-a4


 
 Note that HP-A4 is USB-powered, so don't expect it to drive hungry planars like T50RPs.
 BTW, since it's USB powered, it (might) pick the PC noise, if you have noisy usb power.
 you hear some kind of static like in the background and might "here" the movement of the mouse.
 I still recommend a "mains powered" DAC/AMp over usb powered ones.


----------



## lbbef

limu shirin said:


> Note that HP-A4 is USB-powered, so don't expect it to drive hungry planars like T50RPs.
> BTW, since it's USB powered, it (might) pick the PC noise, if you have noisy usb power.
> you hear some kind of static like in the background and might "here" the movement of the mouse.
> I still recommend a "mains powered" DAC/AMp over usb powered ones.




The A4BL is still running on a SMPS so don't expect it to be super clean though. I'm running my A4 off a LPS and I got to say it's really amazing. But in still in half a mind to change to the A4BL so that I can directly feed it clean 12V power from a LPS instead of through a USB conditioner.

On a side note I did compare between different types of power supplies for my A4. My USB conditioner splits the data and power lines for the USB signal.

In terms of ranking:
LPS > Xiaomi Power bank > SMPS > PC USB Port


----------



## Razornova

limu shirin said:


> Note that HP-A4 is USB-powered, so don't expect it to drive hungry planars like T50RPs.
> BTW, since it's USB powered, it (might) pick the PC noise, if you have noisy usb power.
> you hear some kind of static like in the background and might "here" the movement of the mouse.
> I still recommend a "mains powered" DAC/AMp over usb powered ones.



I believe running a good powered USB hub before the DAC solves most of the USB issues. But noted on the lack of power...


----------



## Limu Shirin

yeah, USB hub helps, but lack of power...


----------



## soundman414

Another option for power is the iFi low noise power supply. I checked the power specs and it would work with the HP-A4BL.

 https://www.bhphotovideo.com/c/product/1275643-REG/ifi_audio_0306007_12v_ipower_12v_improves_sonics.html


----------



## MattRG

Good to see folks having success with the HP-A4BL.  For the price it is a wonderful unit and I'm really enjoying it.


----------



## Limu Shirin

soundman414 said:


> Another option for power is the iFi low noise power supply. I checked the power specs and it would work with the HP-A4BL.
> 
> https://www.bhphotovideo.com/c/product/1275643-REG/ifi_audio_0306007_12v_ipower_12v_improves_sonics.html


 

 I tdon't think they're compatible. Fostex requires 12V-1.5A,
 but iFi power supply is 12V-1.8A, are they compatible?


----------



## soundman414

limu shirin said:


> I don't think they're compatible. Fostex requires 12V-1.5A,
> but iFi power supply is 12V-1.8A, are they compatible?


 
 They are compatible. That power supply is 12V like the HP-A4BL needs, and it can serve *up to 1.8 amps*. The HP-A4BL will only draw the amperage that it needs.


----------



## Limu Shirin

soundman414 said:


> They are compatible. That power supply is 12V like the HP-A4BL needs, and it can serve *up to 1.8 amps*. The HP-A4BL will only draw the amperage that it needs.


 

 ok, thanks. when it comes to such stuff, I'm a noob.


----------



## ciaw525

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.


----------



## MattRG

ciaw525 said:


> 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".
> 
> ...


 
 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

mattrg said:


> 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

noteeater said:


> 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.
> 
> ...


 

 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

limu shirin said:


> 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

likvido said:


> 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

soundman414 said:


> 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

mattrg said:


> 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?


----------



## xenithon

For those that have heard both this and the Jotunheim, how do the sonic signatures compare? From what I have read, the Jot has quite a cold, sometimes harsh sound (hence not pairing well with the likes of the HD800); is the Fostex warmer / fuller or similar in sound character?


----------



## Packdemon

Does anyone know if the built-in DAC in wired in a balanced configuration or not? I know the amp is, but I'm more concerned about the DAC. If it doesn't, then that might be the difference for me in buying the $100 more Jotunheim.


----------



## badlucy999

This machine has pseudo balance, GND separation, so not true balance i think


----------



## Packdemon

badlucy999 said:


> This machine has pseudo balance, GND separation, so not true balance i think


 

 That's unfortunate. And the Jotumheim is not pseudo balanced from what I understand. Or is it?


----------



## MattRG

If you add the balanced DAC module to Jot then it is a fully balanced unit although at $100 more.  If you just want a powerful balanced DAC and amp then the Jot is an easy recommendation but the Fostex supports DSD, fast A/B switching through the output button, roll-off filters and I *believe* has the option to upgrade the opamps.
  
 As a do it all, convenient, attractive all in one solution the Fostex has been very good to me.  I have added a Lyr 2 recently and have been using the Fostex as a DAC only and that has worked out nicely also.  I suppose it comes down to what features are most important to you.


----------



## cs098

can you use the optical out on the fostex to output to another dac that does not support usb?


----------



## lbbef

cs098 said:


> can you use the optical out on the fostex to output to another dac that does not support usb?




Yes


----------



## cs098

sweet


----------



## Kildras

Just got the unit and using it with my el8.
Already can notice the stronger bass compared to my arm2 player. 
It also controls the high better IMO. But definitely needing more time with it before I make any conclusion.

That being said I love both systems, arm2 adds a nice smooth touch to the music.

Going to try out more music and thinking to grab a hd650 later on if I have the funding.


----------



## Takeanidea

soundman414 said:


> 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?


 
 Yes! It was a pain in the backside! First of all the card was too big. It has to be a max size of 32 Gb. 2nd I downloaded the wrong file - I saw the HPA4 so went for that. I needed to scroll down and find the HPA4 BL file. 3rd I had the SD card formatted wrong. It needs to be in FAT on Mac. 4th the order you have to do it in and the way it's written on the website just isn't precise enough to get the firmware to take. It has to be plugged into the mains and switched on to communicate with the USB on the Mac. I'm not even sure how I finally got it to work. I had given up then looked at the sound preferences at the top and it had recognised there was a Fostex there. It took me over an hour and I was tearing my hair out!


----------



## Dartin Bout

I was able to this only after getting the unit to write the version number to a txt file . I had 32G sdhc card. Although the instructions were a little "Lost in Translation", it worked after a couple of tries. I have a windows pc if that helps.


----------



## Takeanidea

I can't get my review model to playback DSD or any flacs above 32 192. It won't playback any youtube or bandcamp at a normal speed. I must have done something wrong with the firmware upload after all. I am running OSX on my Macbook


----------



## Reputator

I tried this Amp/DAC with a Shure SRH1540 and Beyer DT990 600ohm, and it didn't really jive with me. Doesn't seem to have quite enough power for the Beyers, but it's a very demanding phone.
  
I'm selling mine on eBay now, and I'm picking up a Schiit stack instead. I only used mine for about a week, so if you want one of these for $330 + $10 shipping, please follow the link.


----------



## Takeanidea

I've finished my time with the HPA4BL. I did manage to get it working properly with my Mac. I looked at my midi settings and they were set incorrectly. Once I set the default for the HPA to 16 44.1 it worked fine


----------



## Dartin Bout

reputator said:


> I tried this Amp/DAC with a Shure SRH1540 and Beyer DT990 600ohm, and it didn't really jive with me. Doesn't seem to have quite enough power for the Beyers, but it's a very demanding phone.
> 
> I'm selling mine on eBay now, and I'm picking up a Schiit stack instead. I only used mine for about a week, so if you want one of these for $330 + $10 shipping, please follow the link.


 
 I am using this unit with a set of Sennheiser HD650's and it is a wonderful dac\amp, that plays everything up to DSD256 (but not dsd512 music I discovered.I want to publicly apologize to my poor ears for that experiment). It has a balanced out and I found a used set appropriate cables. It also, unsurprisingly, makes my set  of Rostex t50rp mkii (mayflower mod) sing like an angel though the unbalanced out. In both cases, using the high gain, it crosses over 90db at full volume. I can recommend this dac\amp, using the USB in, for both headphones.


----------



## HungryPanda

Just received this wonderful little amp. Got to listen to my LCD-X's balanced for the first time. I have now ordered a balanced cable for my HD650's


----------



## KingFiercer

Has anyone tried to change op amp? Does this make sense here?


----------



## Dartin Bout

Someone earlier in this thread opened this unit up and confirmed there was balanced circuitry but they never came back with the outcome of their investigation. The internals do seem to be quite updat date. I am interested in op amp rolling because I wnet from a set of LM4562 to Muse02 on my Auzentech card and really like the change. There are the Burson 
 Supreme Sound Opamp V5  
  

that I think would fit if there are dip connectors..​


----------



## KingFiercer (May 6, 2017)

So changing OPA2134 will only affect line output?
I tried to listen HP-A4 via USB, the sound was a bit harsher and thinner than I prefer.
Has anyone compared A4 and A4BL? Some owners wrote that A4BL has more bass and power in sound.


----------



## obsidyen

So what is the opamp in this unit, and is it a good one? Is it not possible to change it easily like the first model?


----------



## Sayed2020

For those looking for an external upgrade, I can confirm the iFi iPower 12 volt 1.8 amp power supply works great with this balanced DAC amplifier : )


----------



## davidmthekidd

Anyone else having issue with this dac/amp on windows 10?


----------



## hanouk (Aug 3, 2017)

I have the regular HP-A4 (not BL), received today, I got no sound (even with win10 recognizing it and after having installed the driver). I tried to update the firmware from 1.01 to 1.10 and now it's even worse, my hp-a4 has the 44.1k led flashing red constantly.

Any idea ?


----------



## HungryPanda

Fostex recommend not using with W10


----------



## KingFiercer (Sep 6, 2017)

When using optical toslink there is no annoying problems with sound latency in videos and games, which I have with USB connection on Win7 x64. It's good solution for Win10 I suppose.


----------



## davidmthekidd

Naim.F.C said:


> *This thing rocks.*
> 
> So I ended up purchasing this little baby out of sheer curiosity. I needed a bedside Amp/Dac set up, and as touched upon above, was contemplating between another O2+ODAC, a JDS The Element, Schiit Jotunheim, and this Fostex HP-A4BL. The Fostex was the cheapest to include a balanced XLR output on top of an optical out (for connecting to the PS4 Pro/PS4 or Xbox One), so I thought why not. You can find it from between £360 and £375, which makes it fairly solid value. It's only $350 in the US, which is even better value for money.
> 
> ...




How's that Combination of the MDR-Z1R with the Fostex HP-A4BL??? I Have the A4BL already, I would like to know how does it pair with the Z1R or even the Z7?  Can it produce frequency's under 20Hz?


----------



## Naim.F.C

davidmthekidd said:


> How's that Combination of the MDR-Z1R with the Fostex HP-A4BL??? I Have the A4BL already, I would like to know how does it pair with the Z1R or even the Z7?  Can it produce frequency's under 20Hz?



It pairs fantastically. I use it via USB out as that sounds ever so slightly cleaner and crisper to me than optical which I felt was a touch warmer (could just be placebo). Sonically it pushes my Z1R's and other headphones (HD800, HD800S, LCD-3, T1.1 etc) as well as anything else I've tried, at least at the sort of volume levels I listen to anyway. Never had to push the volume knob more than halfway either. With the German cans I do use the gain mode though.


----------



## HungryPanda

I have to agree this little powerhouse drives everything I have with ease


----------



## davidmthekidd

Naim.F.C said:


> It pairs fantastically. I use it via USB out as that sounds ever so slightly cleaner and crisper to me than optical which I felt was a touch warmer (could just be placebo). Sonically it pushes my Z1R's and other headphones (HD800, HD800S, LCD-3, T1.1 etc) as well as anything else I've tried, at least at the sort of volume levels I listen to anyway. Never had to push the volume knob more than halfway either. With the German cans I do use the gain mode though.



Cool, Adorama had the Audeze LCD-2 on sale today for $650 New, I couldn't let that get away for such price, got em. Also, I went got the Audeze Balanced XLR cables for it aswell, the HP-A4BL drives the LCD-2 Like a champ, specially Balanced, I can barely push the Volume noob to 12 O'Clock, loud as heck. Great Dac/Amp!


----------



## davidmthekidd

Naim.F.C said:


> It pairs fantastically. I use it via USB out as that sounds ever so slightly cleaner and crisper to me than optical which I felt was a touch warmer (could just be placebo). Sonically it pushes my Z1R's and other headphones (HD800, HD800S, LCD-3, T1.1 etc) as well as anything else I've tried, at least at the sort of volume levels I listen to anyway. Never had to push the volume knob more than halfway either. With the German cans I do use the gain mode though.



Perfect, So would you recommend that combination? you dont mind running them via 1/4" instead of Balanced. Last question, Amazon has the international version for $1,599, is it a good idea to get that?


----------



## davidmthekidd

This dac/amp really Drives my Sony's MDR-Z1R like a champ via the SE Cable, in the process of ordering a good custom made Balanced Cable, 4 Pin XLR. Plenty of Juice for the Z1R at 12 O' Clock, no need for High gain, will update once the XLR cable arrives.


----------



## Thujan Krishnakumar

This is my main amp/dac combo. I started with an o2/odac --> Yulong canary daart ---> these. I use em to power my Hd 800s in balanced, fostex th-900s and LCD-3Fs. Is there anything really better.


----------



## davidmthekidd

Thujan Krishnakumar said:


> This is my main amp/dac combo. I started with an o2/odac --> Yulong canary daart ---> these. I use em to power my Hd 800s in balanced, fostex th-900s and LCD-3Fs. Is there anything really better.



I agree, I really feel like this amp is seriously put to use on Balanced, it doubles the power output, it powered the LCD-2's with no issue, plenty loud at 12' O clock. Just ordered a Moon Audio Silver Dragon Balanced Cable for my MDR-Z1R, cant wait to get them.


----------



## escknx

Did Fostex forget to advertise this?
Was looking for balanced amp/dac combo and found A4BL, made In Japan, looks great, pretty fine specs for TH900 and X00.
Got last one from Rakuten for 399.
I see reports that its not fully balanced dac/amp, while others reported as fully balanced circuitry.
Will test it against Burson 9018 Conductor and Chord Hugo.


----------



## davidmthekidd

escknx said:


> Did Fostex forget to advertise this?
> Was looking for balanced amp/dac combo and found A4BL, made In Japan, looks great, pretty fine specs for TH900 and X00.
> Got last one from Rakuten for 399.
> I see reports that its not fully balanced dac/amp, while others reported as fully balanced circuitry.
> Will test it against Burson 9018 Conductor and Chord Hugo.



Let us know your thoughts.


----------



## skingg

Hi, I'm kinda interested with this Fostex amp and was wondering if someone can help answer a couple of questions.

To my understanding, this can be solely usb powered and is good enough for single-ended connections. However if I would like to use the balanced connections, I'd have to get a seperate DC12V adapter to power the amp? Is there a dedicated switch for this or would connecting the DC12V adapter automatically switches the power away from the usb?

Also, does anyone know how does this dac/amp compare to a DAP such as the Onkyo DP-X1A in terms of sound quality?

Thanks in advance.


----------



## Dartin Bout

Uhhh, I'm pretty sure this needs a power source for all use. It comes with it's own power supply. This is my first desktop dac amp. I have used a modified Auzentech X-Meridian sound card, with swappable opamps,before this. I choose this amp for it's balanced out put and it's ability to play up to 11.6 DSD. I use it with the my HD 650 and it's on par with the best peruvian product that I can remember from 30 years ago. My modified Fostex 50rp's sound pretty darn good, with the unbalanced output put, as well.


----------



## davidmthekidd

skingg said:


> Hi, I'm kinda interested with this Fostex amp and was wondering if someone can help answer a couple of questions.
> 
> To my understanding, this can be solely usb powered and is good enough for single-ended connections. However if I would like to use the balanced connections, I'd have to get a seperate DC12V adapter to power the amp? Is there a dedicated switch for this or would connecting the DC12V adapter automatically switches the power away from the usb?
> 
> ...



This dac/amp is meant to be powered by the 12v power supply, if you want USB go with the older HP-A4, that's only USB powered.


----------



## scottsays

I am doing research on DAC balanced headphone amps---I am looking at the Fostex Hp-a4 bl and Schiit Jotunheim.
Both are around $ 500 new. If anybody can give me some advice I would be grateful. My headphones are Focal Utopia and Fostex TH 900 with silver dragon cable upgrade.
I am treble sensitive if that makes any difference in these amps.
If there are other any other balanced/dac amps that are also high quality, please advise.
I would like to spend around $ 500----not quite ready to go crazy with all the recent purchases.
Thank You===


----------



## davidmthekidd

scottsays said:


> I am doing research on DAC balanced headphone amps---I am looking at the Fostex Hp-a4 bl and Schiit Jotunheim.
> Both are around $ 500 new. If anybody can give me some advice I would be grateful. My headphones are Focal Utopia and Fostex TH 900 with silver dragon cable upgrade.
> I am treble sensitive if that makes any difference in these amps.
> If there are other any other balanced/dac amps that are also high quality, please advise.
> ...



Look at the review by ZReviews.


----------



## scottsays

Thanks--I will check it out. Much appreciated!


----------



## involuntarysoul

what is the benefit of balanced amp when the internal DAC is not balanced?


----------



## skingg

Quick question. Since this is a Made in Japan dac/amp, does the AC adapter that comes with it supports 100V to 240V?


----------



## KingFiercer

skingg said:


> Quick question. Since this is a Made in Japan dac/amp, does the AC adapter that comes with it supports 100V to 240V?


Yes, it does.


----------



## skingg

KingFiercer said:


> Yes, it does.



Thank you!


----------



## GU1DO

scottsays said:


> I am doing research on DAC balanced headphone amps---I am looking at the Fostex Hp-a4 bl and Schiit Jotunheim.
> Both are around $ 500 new. If anybody can give me some advice I would be grateful. My headphones are Focal Utopia and Fostex TH 900 with silver dragon cable upgrade.
> I am treble sensitive if that makes any difference in these amps.
> If there are other any other balanced/dac amps that are also high quality, please advise.
> ...


i had the silver dragon with my TH-900 before and it was crazy hot ,, 
switch the cable to black dragon if you want less treble 900 , i think this is a better choice to spend 500$


----------



## GU1DO

involuntarysoul said:


> what is the benefit of balanced amp when the internal DAC is not balanced?


balanced amp give more power , even there HP-V8 high end fully balanced amp have SE input ..


----------



## KingFiercer

Can anyone explain, does opamp affects only on headphones out?


----------



## mircea (Nov 23, 2017)

Hi guys,

I've been reading this thread from the first page but I found little information about the DAC capability of this Fostex.
I am planning to buy this model to link my laptop to my Yamaha HS8 active studio monitors, so what is your opinion about the Digital to Analog conversion capability of this model?
Maybe someone did a similar configuration and can share with us his/her's feedback?

Thank you in advance!
Mircea


----------



## SethGG

Hey people,

In the product manual it says you're not supposed to use 3rd party ac adapters.
Is this really a problem or does fostex just say that for legal reasons?


----------



## KingFiercer (Dec 10, 2017)

It's only attention for casual users. You can buy 30W DC12V Linear Power Supply from ebay and it will pretty improve sound quality.


----------



## SethGG

KingFiercer said:


> It's only attention for casual users. You can buy 30W DC12V Linear Power Supply from ebay and it will pretty improve sound quality.


Thanks!

So if I were to import one from japan do I just need to buy an AC adapter with an EU plug or do i also need a 230v-110v transformer?


----------



## KingFiercer (Dec 11, 2017)

No transformer needed, it's 100-240V already. You only need adapter to EU plug.


----------



## SethGG

KingFiercer said:


> No transformer needed, it's 100-240V already. You only need adapter to EU plug.


Thank you for the help, makes things a lot easier.


----------



## grnsk

Hey guys. Long time lurker here. Do you guys have latency issues with your HPA4-BLs watching videos? If I watch youtube or other videos there is a clear sync problem with the sounds and the picture, probably around 200-300ms. Anyone have a solution to fix this. My HPA4-BL is connected to Win10 via USB. Any help would be appreciated.


----------



## Naim.F.C

grnsk said:


> Hey guys. Long time lurker here. Do you guys have latency issues with your HPA4-BLs watching videos? If I watch youtube or other videos there is a clear sync problem with the sounds and the picture, probably around 200-300ms. Anyone have a solution to fix this. My HPA4-BL is connected to Win10 via USB. Any help would be appreciated.



Whilst I don't have this issue, there is an easy fix. Download VLC player, and when playing a video using the player, use the shortcuts to adjust audio delay or sync to your ideal preference or whatever you think seems most accurate.

https://wiki.videolan.org/VLC_HowTo/Adjust_audio_delay/


----------



## grnsk

Naim.F.C said:


> Whilst I don't have this issue, there is an easy fix. Download VLC player, and when playing a video using the player, use the shortcuts to adjust audio delay or sync to your ideal preference or whatever you think seems most accurate.
> 
> https://wiki.videolan.org/VLC_HowTo/Adjust_audio_delay/



Thank you, that fixes part of the problem. I occasionally also play some games and there the issue is even worse. I'd like to know if this is just some driver issue or if it can't be fixed because that would be a deal breaker for me :/. Otherwise I really like the unit both for sound quality and it's functions.


----------



## KingFiercer (Jan 12, 2018)

Same problem with Win7. I'm using optical-in for Windows and USB for audio-player, that is solution.


----------



## skingg

KingFiercer said:


> Same problem with Win7. I'm using optical-in for Windows and USB for audio-player, that is solution.



So I suppose using optical-out from Windows/mainboard to the Fostex instead of connecting it via usb should solve the latency issues?


----------



## KingFiercer

That's right.


----------



## albocaj

Is there a tutorial somewhere on how to update the fw on Mac? Anything helps...


----------



## carter840

Any thoughts on this vs. an Audio GD R2R 11?


----------



## skingg

I'm be picking up this dac/amp over the next week or two. For those who owns the unit, has the driver been updated to work with the latest Windows 10? If so, are we required to flash the latest firmware to the Fostex to work?


----------



## Dartin Bout

that's what I did to use the Fostex  USB Audio. DSD's sound great.


----------



## davehutch

Quick opinion if you wouldn't mind please someone.
Currently using a SE Grace Design m9xx with Sennheiser HD6xx and looking at a balanced DAC/Amp. I probably wouldn't upgrade again for some years.
I can get this for £299 as an 'Open Box' or I could go with Jotenheim or Audio-GD NFB11, both more expensive of course, especially he Jot.

I listen to all sorts, but mostly acoustic, jazz and I wouldn't need balanced analogue inputs.

Any major advantages/drawback you can think of?


----------



## HungryPanda

davehutch said:


> Quick opinion if you wouldn't mind please someone.
> Currently using a SE Grace Design m9xx with Sennheiser HD6xx and looking at a balanced DAC/Amp. I probably wouldn't upgrade again for some years.
> I can get this for £299 as an 'Open Box' or I could go with Jotenheim or Audio-GD NFB11, both more expensive of course, especially he Jot.
> 
> ...


None whatsoever, I listen to a lot of genres, Folk, Americana, Blues, Jazz, EDM, Progressive rock, Classical and the Fostex amp deals with them all fine


----------



## kukkurovaca

davehutch said:


> Quick opinion if you wouldn't mind please someone.
> Currently using a SE Grace Design m9xx with Sennheiser HD6xx and looking at a balanced DAC/Amp. I probably wouldn't upgrade again for some years.
> I can get this for £299 as an 'Open Box' or I could go with Jotenheim or Audio-GD NFB11, both more expensive of course, especially he Jot.
> 
> ...



Even in balanced, the HPA4BL will have less output power than your Grace m9xx, FWIW.


----------



## davehutch (Mar 1, 2018)

Wow, really? The Grace Design is USB powered (5v 2A adaptor option)  and gives you 110mW into 300 ohms. I just figured with a 12V supply, balanced output and a high gain switch I'd get more.
I've looked everywhere and can't find the official specs for 300 ohm headphones, so did you find them somewhere or have you experienced both amps?


----------



## kukkurovaca

I was comparing the output at 32 ohms (300mw), since that's the only rating that Fostex provides in the specs.


----------



## HungryPanda (Mar 1, 2018)

the fostex is quite powerful and powers all my headphones without ever maxing out and only need high gain for my HE-560s or HD650s


----------



## davehutch

HungryPanda said:


> the fostex is quite powerful and powers all my headphones without ever maxing out and only need high gain for my HE-560s or HD650s



Thanks. My 650s will appreciate that


----------



## davehutch (Mar 3, 2018)

OK, my main reservation is that, if I'm 'upgrading' from my Grace Design and not intending to buy another DAC/Amp for a few years, is this a bit of a sideways move rather than an upward one?

My options currently look like this:

Fostex HP-A4BL     £299
Audio-GD R2R-11   £360 (Single ended only but highly regarded)
Schiit Jotenheim     £520

My think is that a DAC is a DAC is a DAC to some extent, but for the HD650s, the amp would play the most vital role.
With the Fostex being the lowest powered and the Jot the highest, each choice has its disadvantage I guess?

Any assistance would be grateful appreciated as I can't hear any of these before purchase except maybe the Fostex.


----------



## kukkurovaca

In the same rough product category as the Fostex and Jot would be the Topping DX7/DX7s

A lot of folks like tubes with their Sennheisers or tube-y-er solid state amps like the Garage1217 Polaris


----------



## davehutch

kukkurovaca said:


> In the same rough product category as the Fostex and Jot would be the Topping DX7/DX7s
> 
> A lot of folks like tubes with their Sennheisers or tube-y-er solid state amps like the Garage1217 Polaris


I did look at the Topping but reviews aren’t the best to be honest. Probably need an upwards move rather than maybe a ‘sideways’ one. 
I’ve re-read the whole m9xx thread and it sounds like I would be wise to keep what I have for the time being. The Joy’s DAC isn’t as good apparently although the amp is better. 
I doubt the Fostex is better in either aspect but maybe the Audio-GD is still very promising


----------



## kukkurovaca

davehutch said:


> I did look at the Topping but reviews aren’t the best to be honest. Probably need an upwards move rather than maybe a ‘sideways’ one.
> I’ve re-read the whole m9xx thread and it sounds like I would be wise to keep what I have for the time being. The Joy’s DAC isn’t as good apparently although the amp is better.
> I doubt the Fostex is better in either aspect but maybe the Audio-GD is still very promising



You could also pick up a DAC-less Jotunheim (or other amp) and continue to use the m9xx as your source. The Jotunheim doesn't require a balanced input.


----------



## davehutch

kukkurovaca said:


> You could also pick up a DAC-less Jotunheim (or other amp) and continue to use the m9xx as your source. The Jotunheim doesn't require a balanced input.


Thanks, yes, I did think about that but as I have limited space i.e. no 'desk' I should really stick to a one-box solution.


----------



## Ad-Astra

Is it a dac with a small amp?


----------



## davehutch

Ad-Astra said:


> Is it a dac with a small amp?


The Grace Design? It’s a good DAC with a pretty reasonable amp. It’s on their website and now called the m900


----------



## davehutch

Anyone seen/heard the Klipsch Heritage DAC/Amp? Balanced out and seems to have a lot more power than the Fostex. Looks are very 'Marmite' but personally I like it. Balanced amplifier and a single Sabre DAC
I read the review on Headfonia and it could be an option.


----------



## davehutch

I managed to eventually find my missing extended, tuneful bass and my extra soundstage width and some musicality...I found it inside my new Fostex HP-A4BL.
Plugged my Hd6xx in and there it was all the time!


----------



## KinoS

davehutch said:


> I managed to eventually find my missing extended, tuneful bass and my extra soundstage width and some musicality...I found it inside my new Fostex HP-A4BL.
> Plugged my Hd6xx in and there it was all the time!



You sound pretty happy. I'm curious, how would you describe the difference between the Fostex and the Questyle CMA400i? I seem to recall we were trying the Questyle around the same time with the HD650/HD6XX.


----------



## davehutch

KinoS said:


> You sound pretty happy. I'm curious, how would you describe the difference between the Fostex and the Questyle CMA400i? I seem to recall we were trying the Questyle around the same time with the HD650/HD6XX.


Well, I could barely hear any difference between my m9xx and the 400i, but I must admit I do sometimes struggle and maybe I just didn’t play the right selection of tracks. 
Given the opportunity again I might have a better idea of what to listen out for but the biggest issue was that I didn’t have a reliable balanced cable last time. One channel kept cutting out. This time I made my own. 
If I were to guess, I’d say I couldn’t justify paying double the price for the 400i as the differences are likely to tiny between that and the Fostex, at least in my case.


----------



## kvn864 (May 3, 2018)

What I can see so far is (main components):
1 DAC PCM1792(A)
3 opamps 2114D (whatever they do)
2 TPA6120A2 High Fidelity Headphone Amplifier (I guess for balanced out)
1 OPA2134 for SE?? (sits in the socket, swapable)
Won't go much to the sound, as I just got it. Are the socks off my feet? No. Is it a good dac/amp? Yes.
Listening with TH900, HD650, Utopia.


----------



## Dartin Bout

Holy flipping hell, is that a replaceable opamp? I think this would take a full dual Burston V6. I've wanted to know if this was possible since I got this lovely dac\amp for my HD650's.


----------



## skingg

Dartin Bout said:


> Holy flipping hell, is that a replaceable opamp? I think this would take a full dual Burston V6. I've wanted to know if this was possible since I got this lovely dac\amp for my HD650's.



Coincidentally I had just purchased this dac/amp last month and my HD650 arrived last week. However haven't had much time to listen to these babies yet.


----------



## KingFiercer (Apr 11, 2018)

Tried OPA637BP, OPA1642, OPA2604, but default OPA2134 still the most balanced sound overall. Next is 1642, but it's too fast and a bit fatiguing. 2604 is a bit harsh and with slightly recessed mids. 637 is bold, natural, nice resolution, but have a bit bloated ~100Hz bass and less upper highs.
Now waiting for arriving of OPA2209. Maybe it will be better than stock 2134.


----------



## kvn864

here is what I always think when I see "opamp swapping thing". most likely the original would work the best, within its specs, because there are people that designed the thing, and some amount of thought and testing was put in before they decided to go with one or the other. and trying to challenge that would be "hunting ghosts", I have done it myself on a different equipment, and results I got make me say what I just said. its exciting to do though


----------



## Dartin Bout

Please forgive me, but is the swap able op amp is the one that control the balanced output or the SE?


----------



## KingFiercer

Burson V6 may be too tall for this DAC. You need smaller opamp. Swapping affects both line-out and RCA-out.


----------



## Dartin Bout

The shorter burson would fit. https://www.bursonaudio.com/products/supreme-sound-opamp-v5i/ 
I've been playing with ooamp swapping with my Auzentech, Currently  running Muse 2 in a 5.1 configuration. So if the V6  are too big after I get them, they would still have a good home..
Are you saying swapping the opamp in the Fostex would't affect either the balanced or single end outputs?


----------



## Cozmo85

davehutch said:


> Anyone seen/heard the Klipsch Heritage DAC/Amp? Balanced out and seems to have a lot more power than the Fostex. Looks are very 'Marmite' but personally I like it. Balanced amplifier and a single Sabre DAC
> I read the review on Headfonia and it could be an option.



I have one and really like it. I have lcd-x plugged into the balanced output and yea, it puts out a ton of power.


----------



## davehutch

Cozmo85 said:


> I have one and really like it. I have lcd-x plugged into the balanced output and yea, it puts out a ton of power.


I bought the Fostex a few weeks ago and it sounds great. Much better, lower bass than my m9xx and nicely musical. With my HD6xx and balanced output, I'm running it at about 1 o'clock on the volume knob. Happy days.


----------



## Stop_Whispering

grnsk said:


> Thank you, that fixes part of the problem. I occasionally also play some games and there the issue is even worse. I'd like to know if this is just some driver issue or if it can't be fixed because that would be a deal breaker for me :/. Otherwise I really like the unit both for sound quality and it's functions.


I am sorry for the late reply, but I just purchased the HP-A4BL coming from the Schiit Fulla 2. I had the same problem especially in games. I went in the device properties under windows and turned off enhancements and forced the bit rate to 24/192. That solved my issue.


----------



## Yevgen Chupak

Hey guys. I need your help.

I have a combo of A4BL + Emotiva A100 Bas X as my external amplifier for some hard cans.
And whenever I'm using my Shure 1540 I can hear EMI hiss A LOT (can hear much less with Senh hd600 and Shure 846). Those cans are pretty sensitive unline my many others (Fostex, Senh, Sony, M1060 etc)

If I USB cable is unplugged from A4 hiss is almost gone (stock silver cable). I thought that if i will get myslef AQ Jitterbug it will fix my problem but nope... no difference.

So my question is anyone of you have the same problem with A4 as DAC and what is the way to fix that? So should i go and buy some fancy USB A-B cable? Or I should get Linear Power Supply for A4? Anything?


----------



## baseonmars

I wonder if the problem might be more related to the computers USB interface and the way it interferes with its PSU. Can you try out another computer/laptop?

I can turn the HP-A4BL up fully and I don't think I've heard any hiss what-so-ever, although I've only tried over ear headphones (Fostex 610's and Fidelio X2's). That's without music playing.

I've seen some older threads suggesting using a powered USB hub helped - in their case it seemed to be a grounding issue.


----------



## Yevgen Chupak

did another round of tests with MacBook Pro (on battery) instead of my mac pro as a source. Noise is still there but 20-30% less. With my LGv20 connected directly to Emotiva there is no hiss.


----------



## skingg

Have you tried hooking up the A4BL with optical connection instead of usb?


----------



## Yevgen Chupak

skingg said:


> Have you tried hooking up the A4BL with optical connection instead of usb?


Not yet. Need to buy that cable first. On my list.


----------



## ACDOAN

Yevgen Chupak said:


> Not yet. Need to buy that cable first. On my list.



*Fostex Products and Windows 10 / Mac OS X 10.11 (El Capitan) Compatibility*


We have not confirmed the compatibility with Windows 10 and Mac OS X 10.11 (El Capitan) for our USB DAC products yet.  We will keep updating the compatibility status on our website.

In order to continue to use our USB DAC products, we recommend staying with the current OS for the time being.
Thank you for your kind understanding.


----------



## Yevgen Chupak

ACDOAN said:


> *Fostex Products and Windows 10 / Mac OS X 10.11 (El Capitan) Compatibility*
> 
> 
> We have not confirmed the compatibility with Windows 10 and Mac OS X 10.11 (El Capitan) for our USB DAC products yet.  We will keep updating the compatibility status on our website.
> ...



As far as i know there is a new firmware on their official web... that adds compatibility. Once i bought it it was not detected under my 10.11.2 But once firmware was updated it's ok now.


----------



## Yevgen Chupak

Get myself new UBS and interconnect cables. AQ Forrest and AQ Evergreen. Not much difference. Same with cheap optical cable.

Next on my list is to get UPS and connect all via surge. Will see


----------



## ACDOAN

Yevgen Chupak said:


> Get myself new UBS and interconnect cables. AQ Forrest and AQ Evergreen. Not much difference. Same with cheap optical cable.
> 
> Next on my list is to get UPS and connect all via surge. Will see



I did the driver download  yesterday it showed up on my playback/sound but there was no hand shake between the two, no output. I used the optical connetion for now.


----------



## skingg

ACDOAN said:


> I did the driver download  yesterday it showed up on my playback/sound but there was no hand shake between the two, no output. I used the optical connetion for now.


I only purchased the Fostex last month @ Bic Camera. The driver was the only thing I installed on my Windows 10 Pro and currently hooked up via usb connection. I haven't been able to check the firmware of my unit as it requires a size 32 gigs sdcard and below (my lowest capacity sdcard is 64gigs).


----------



## benchan2

The more I look at it, the more I am certain that Klipsch heritage amplifier is also a "collabration" between Klipsch and Fostex. So IMO it is like an updated Fostex HP-A4BL. 
While it would look dope especially pairing up with my E-MU teak, I am afraid as soon as I get one， Fostex would immediately announce an actual updated version of HP-A4BL....


----------



## davehutch

Especially when you look at the original images of the Klipsch when it was first shown:
http://www.avsforum.com/klipsch-tea...er-ear-headphones-and-usb-dacamp-at-ces-2017/
and
https://smart-sound.jp/stuffblog/blog/klipsch-heritage


----------



## skingg

Curious but which music player do the lot of you use on Windows with the Fostex? I've always been using Foobar and up until last night, I only realized I've been using the A4BL with the default primary audio driver which I assume was the Realtek audio driver of my Asus mainboard when listening with Foobar. Upon switching to the Fostex driver, I noticed that there is a 'lag' whenever I turn up or down the volume control of the Foobar, which is not present when I was using the primary driver.

However, I haven't had the chance to A/B test since it was getting pretty late last night but to those of you that had experiences, are there any notable difference in audio quality between the Fostex driver and the default Windows/Realtek driver? I also just realized r there is Fostex Audio player for download from its website. How does it compare with Foobar (or any players you folks are presently using)?


----------



## HungryPanda

I use Foobar 2000 and in widows sound devices have fostex dac properties set at 24 bit, 192000 Hz (Studio Quality) with Exclusive modes checked and in Foobar output DSD:WASAPI (push) : Dac/amp (FOSTEX USB Audio HP-A4BL)


----------



## Ziggity (May 9, 2018)

Hello everyone. Long time lurker here. Since I've never posted here in the past and I'm restricted from other areas of the site, I wanted to mention here that if anyone's looking to sell his HP A4BL then I'm interested in a unit for a reasonable price, roughly around the 300$-350$ area depanding on use and what not. PM me if you got an offer.

Thank you and have a good day =]


----------



## HungryPanda

Hope you get one Ziggity


----------



## KingFiercer

skingg said:


> Curious but which music player do the lot of you use on Windows with the Fostex?


For me FOSTEX ASIO Driver in foobar forcing bass. WASAPI (FOSTEX USB AUDIO) seems more neutral.


----------



## skingg

KingFiercer said:


> For me FOSTEX ASIO Driver in foobar forcing bass. WASAPI (FOSTEX USB AUDIO) seems more neutral.


When you say forcing bass, do you mean with foobar's built-in equalizer?


----------



## KingFiercer

No, I'm not using equalizer. Just noticed that ASIO have more focus on deepest lower bass. And for me WASAPI output sound is more neutral and comfortable.


----------



## kse617

Stop_Whispering said:


> I am sorry for the late reply, but I just purchased the HP-A4BL coming from the Schiit Fulla 2. I had the same problem especially in games. I went in the device properties under windows and turned off enhancements and forced the bit rate to 24/192. That solved my issue.



I've been using my HP-A4 for months from the optical port on my motherboard because of the latency issues over USB but looks like some combination of the latest W10 patch, using Microsoft drivers dated 11/04/2018 and selecting 32bit-192kHz on the control panel fixed the issue. Thanks for bringing it up!

This means no 3rd party software installed, even if it's from Fostex, UAC2 might be working its magic here.


----------



## skingg

KingFiercer said:


> No, I'm not using equalizer. Just noticed that ASIO have more focus on deepest lower bass. And for me WASAPI output sound is more neutral and comfortable.



Just noticed you have the the A4-BL connected to the AT-HA22TUBE. May I ask what do you think of the sound of Audio Technica tube amp from the Fostex? And is the set up from the Fostex through the RCA output selector to the RCA inputs of the Audio Technica? Hence the Fostex would act as a 'lineout/preamp" to the Audio Technica HA22Tube, am I correct?

My bad I'm a little fuzzy when it comes to these as I'm still pretty clueless when it comes to lineout/preamp connectivity and stuff.


----------



## KingFiercer (Jul 17, 2018)

Yeah, RCA-output volume can be adjusted on Fostex, but I recommend to set it to max when using with external amp for best sound quality. But if you use something like AC amplifier (w/o volume control) you can easily use Fostex like preamp.
AT-HA22TUBE gives me what I want for Fostex sound upgrade - more openess, fluidity and macrodynamics. It's more natural and musical without any tube flavor.


----------



## skingg

KingFiercer said:


> Yeah, RCA-output volume can be adjusted on Fostex, but I recommend to set it to max when using with external amp for best sound quality. But if you use something like AC amplifier (w/o volume control) you can easily use Fostex like preamp.
> AT-HA22TUBE gives me what I want for Fostex sound upgrade - more openess, fluidity and macrodynamics. It's more natural and musical without any tube flavor.


Thanks. I'll try to see if I can sample these somewhere later in the year. Were you listening to them on stock tubes or have you rolled any? Any noticeable faults that I should know about? I noticed that the tubes are covered, doesn't this make it warmer than usual?

I'm looking for something that can pair well with the HD650 and the Fostex TH500RP; the latter being really picky.


----------



## KingFiercer (Aug 13, 2018)

Check out this thread https://www.head-fi.org/threads/audio-technica-at-ha22tube-in-depth-review.788625/
I'm using mine without cover, it looks better. I'm tried Genelec and Tesla NOS tubes, and found that stock tubes better overall, more neutral and balanced sound. Genelec is more dense and dynamic sound, but with lesser soundstage height. Good choice for rock and vocal music.


----------



## Ziggity (Jul 25, 2018)

Well, I was finally about to get my hands on an HP A4BL after a friend of mine got back from a trip to Japan, since on Amazon Japan its roughly 100$ cheper than it is on the american one.
I only had an Audioengine D1 up until now but as far as I'm concerned, the A4BL sounds great, looks sexy AF and drives my HD 6XX with ease. I also use it as a dac and preamp for my LSR 305 and I've noticed an improvement over my D1. And on top of that, it has the magical button that allows me to switch between the headphones output and the RCA output for my monitors.

Overall, I'm happy =]


----------



## dsnedeco

Purchased  a Fostex HP-A4BL and can't find a source for the newest USB Audio Driver Version 2.21. I've spent hours searching.  Anybody ideas?
I'm a new member so please tell me if I am in the wrong place.


----------



## Ziggity

I just downloaded the latest driver from Fostex's website and everything worked fine. I'm on windows 10
https://www.fostexinternational.com/docs/products/HP-A4BL.shtml


----------



## volly

@Ziggity - Beautiful setup mate, looks tight!!!

How's the setup sound too you?! Looking at getting one myself but will probably be pairing it with Edition X's, I don't have the heart to pull my 650's away from the Darkvoice just yet! Although I do have a balanced connector for the 650's, so the A4BL could be doing double duty.


----------



## dsnedeco

Wow.  Thanks Ziggity. That was just what I needed.  Got it installed and it works great.  I have been using the Fostex HP-A3 for quite a while.  Recently I upgraded HP from HD600 to HD800S and was really anxious to get a listen.  Looks like I'll be busy doing that for a while!!!


----------



## skingg

Quick question. Equalizer APO will not work when we are on ASIO or WASAPI audio drivers, am I right?


----------



## Ziggity

volly said:


> @Ziggity - Beautiful setup mate, looks tight!!!
> 
> How's the setup sound too you?! Looking at getting one myself but will probably be pairing it with Edition X's, I don't have the heart to pull my 650's away from the Darkvoice just yet! Although I do have a balanced connector for the 650's, so the A4BL could be doing double duty.



Thanks man =]

I don't have too much experience with audio equipemt but what I can say for certain is that it sounds great. Everything sounds balanced and detailed, and just a touch warm which is how the HD 6XX are supposed to sounds like. But to be honest, the A4BL isn't the most powerful amp there is and you'd probably want to make sure it can drive the Edition X properly. If budget isn't a concern, maybe should can have a look at the Questyle CMA 400i. I've tried it a friend's and it feels like it does everything the A4BL does but more.


----------



## dsnedeco

skingg said:


> Quick question. Equalizer APO will not work when we are on ASIO or WASAPI audio drivers, am I right?


Actually I have been unable to get the HP-4ABL to work with Equalizer APO.  I also have the Fostex HP-A3 32-Bit DAC Amp and it works great with Equalizer APO.  I have spent enough time with the HP-4ABL without success so I sending it back.


----------



## volly

@Ziggity - The A4BL spec's tick a lot of my boxes, just need to hear one now. I'm a fan of Bur Brown dac's and I've yet to go balanced. I'm not worried about power, love the Edition X's as they run fine off an oily-rag! 

I had an A3 a while back, was a great little unit but gave it to a friend. Was a decent sounding Dac/amp combo for anyone starting out.


----------



## ShamuellJackson

Was looking for some random info on this dac/amp combo and ran into this thread. For Equalizer APO I use the Peace plug-in with it and it seems to work. I use A4BL with my LCD2C and It was feeling a little bass light to me so I used the combo of Equalizer APO and Peace and it sounds fantastic to me for my taste. There was some oddness where I needed to restart my PC a couple of times before the EQ settings would work at all. But after that it has worked ever since the first time I had restart it a couple of times.


----------



## dsnedeco

@ShamuellJackson it sounds like we have a very similar setup. I use the PEACE equalizer front-end for EqualizerAPO also. I had a similar experience with it being unpredictable at startup. For some reason that seems to have resolved itself. As it turns out I didn't send the A4BL back.  And that's a good thing. I'm using Windows 10 so I had to get the latest USB driver for the A4BL. Also I had to tweak the configurator for EqualizerAPO to register the A4BL.  I have age-related hearing loss (only on the high end) and am an extreme bass fan. Using this setup with my HD 800S phones has provided me with the best, most enjoyable, listening experience I have ever had!


----------



## ShamuellJackson

Yeah I was surprised at how well the A4BL takes to EQ settings. On other setups it always felt like I was doing something wrong with the EQ or something and got odd sounding music but with this dac/amp what I change seems like what I hear and so far I am loving it.


----------



## skingg

How are you guys outputting the playback ('m assuming using Foobar player)? Direct sound, ASIO or WASAPI? I used to set up Viper4Windows together with EqualizerAPO on my other devices; they worked until recently however both of them have never worked on the A4BL.


----------



## HungryPanda

I'm outputting DSD Wasapi


----------



## dsnedeco

ShamuellJackson said:


> Yeah I was surprised at how well the A4BL takes to EQ settings. On other setups it always felt like I was doing something wrong with the EQ or something and got odd sounding music but with this dac/amp what I change seems like what I hear and so far I am loving it.



I agree. It is so easy to experiment with different curves. I have been tweaking EqualizerAPO via PEACE for several weeks and have finally more or less settled in on my favorite equalizer curve. Keep in mind that I have a high-frequency hearing loss and that I love bass and maybe you can understand why I eventually set my curve up this way:
<equalizationeffect>
   <curve name="test export">
       <point f="30" d="13.5"/>
       <point f="40" d="9.5"/>
       <point f="60" d="5"/>
       <point f="80" d="2"/>
       <point f="140" d="-1"/>
       <point f="300" d="-2.5"/>
       <point f="600" d="-3"/>
       <point f="1000" d="-1.5"/>
       <point f="1500" d="0"/>
       <point f="2000" d="2.5"/>
       <point f="3000" d="5"/>
       <point f="4500" d="7"/>
       <point f="16000" d="9"/>
       <point f="7000" d="10.5"/>
       <point f="10000" d="12"/>
   </curve>
</equalizationeffect>


----------



## dsnedeco (Aug 5, 2018)

skingg said:


> How are you guys outputting the playback ('m assuming using Foobar player)? Direct sound, ASIO or WASAPI? I used to set up Viper4Windows together with EqualizerAPO on my other devices; they worked until recently however both of them have never worked on the A4BL.


I am streaming from Google Play Music  to my HD800s using this hardware/software:
ACER Predator 15 Laptop G9-593-71EH
Windows 10 Home 10.0.16299 Build 16299
x64-based PC
i7-7700HQ CPU @ 2.80GHz, 2801 Mhz, 4 Core(s), 8 Logical Processor(s)RAM 16.0 GB
BIOS Insyde V1.11, 6/26/2017
Audio via WASAPI
FOSTEX USB Audio HP-A4BL
c:\windows\system32\drivers\fostexua.sys (2.2.1.0, 187.61 KB (192,112 bytes), 11/7/2017 2:43 PM)
EqualizerAPO 1.2
PEACE 1.4.6.3


----------



## ShamuellJackson

I could be wrong but I always thought when using ASIO or WASAPI bypassed any hardware or eq changes you make in windows?


----------



## dsnedeco

ShamuellJackson said:


> I could be wrong but I always thought wot worhen using ASIO or WASAPI bypassed any hardware or eq changes you make in windows?


You very well could be right.  I just saw that listed in a system info print out. My system features  Dolby Audio which does not with work USB audio output.


----------



## HungryPanda

Yes I bypass all windows sound and let the HPA4BL do all the work


----------



## skingg

I'm confused. If both ASIO and Wasapi are bypassing all the sounds and equalizer settings from Windows, then shouldn't Peace/Equalizer APO not be working? Or are they only bypassed when using USB connection because this is what I'm hooked up to?


----------



## ShamuellJackson

skingg said:


> I'm confused. If both ASIO and Wasapi are bypassing all the sounds and equalizer settings from Windows, then shouldn't Peace/Equalizer APO not be working? Or are they only bypassed when using USB connection because this is what I'm hooked up to?



If I understand how Wasapi and ASIO work then yeah your eq's are not sent to your dac and that the dac handles the pure un-messed with signal(sorry this is the best way I know to describe it). There is an exclusive and mixed mode you can use with at least Wasapi and I know exclusive will not send any eq or anything outside the bits of the music. I'm not sure if Foobar supports mixed and if mixed will send your eq  settings. I honestly have no idea how mixed works and hopefully someone more knowledgeable can chime in.


----------



## Ghaunty22

Is the front face just glossy plastic or something else like glassy scratch resistant?


----------



## HungryPanda

It just looks like plastic to me


----------



## dsnedeco

Ghaunty22 said:


> Is the front face just glossy plastic or something else like glassy scratch resistant?


I can't tell.  Could be either.  Why do you ask?


----------



## ShamuellJackson

I think it is plastic. i'm usually poking headphones into it in the dark and i'm not seeing any scratches around either of the headphones out in the front.


----------



## EdibleMind_X

HungryPanda said:


> Yes I bypass all windows sound and let the HPA4BL do all the work


Hi, I’m new to amp/dac world. Could you please tell me how to use HP-A4BL? I have a Walkman (WM1A), don’t know how to connect it to the amp. Do I need a portable mp3 player as a audio input of the amp? Cheers.


----------



## HungryPanda

The Fostex HP-A4BL is a PC desktop amp with a USB or optical input. I would think if you had optical out from a dap it should work in theory


----------



## dsnedeco

EdibleMind_X said:


> Hi, I’m new to amp/dac world. Could you please tell me how to use HP-A4BL? I have a Walkman (WM1A), don’t know how to connect it to the amp. Do I need a portable mp3 player as a audio input of the amp? Cheers.


There are only two types of inputs: USB and Optical.  You will have to figure out how to get your audio in via one of those.


----------



## davehutch

EdibleMind_X said:


> Hi, I’m new to amp/dac world. Could you please tell me how to use HP-A4BL? I have a Walkman (WM1A), don’t know how to connect it to the amp. Do I need a portable mp3 player as a audio input of the amp? Cheers.


From what I can tell on Sony’s website, you don’t have an optical output so you might be able to use the USB connector instead. However, it’s unclear whether that is a digital audio output or simply a way of transferring music files onto the device. I suspect the latter. 
If that’s the case, you cannot connect it to the Fostex as the Fostex doesn’t have an analogue input. 
Try the USB connector but I suspect you can’t connect the two devices at all
I might be wrong so ask on the Sony Forum to make aure


----------



## EdibleMind_X

HungryPanda said:


> The Fostex HP-A4BL is a PC desktop amp with a USB or optical input. I would think if you had optical out from a dap it should work in theory


Thanks a lot.


----------



## EdibleMind_X

dsnedeco said:


> There are only two types of inputs: USB and Optical.  You will have to figure out how to get your audio in via one of those.


Yeah. I guess I can only use digital stream as input


----------



## EdibleMind_X

davehutch said:


> From what I can tell on Sony’s website, you don’t have an optical output so you might be able to use the USB connector instead. However, it’s unclear whether that is a digital audio output or simply a way of transferring music files onto the device. I suspect the latter.
> If that’s the case, you cannot connect it to the Fostex as the Fostex doesn’t have an analogue input.
> Try the USB connector but I suspect you can’t connect the two devices at all
> I might be wrong so ask on the Sony Forum to make aure


I’ve checked. It does have a digital out. Thanks very much!


----------



## Ghaunty22

dsnedeco said:


> I can't tell.  Could be either.  Why do you ask?


Because if its really made in Japan it will be some decent  scratch resistance that can take a microfiber cloth to clean the figer prints. Would hate for it to be like a cheap dvd player front plastic that scratches with dry tissue.


----------



## dsnedeco

Ghaunty22 said:


> Because if its really made in Japan it will be some decent  scratch resistance that can take a microfiber cloth to clean the figer prints. Would hate for it to be like a cheap dvd player front plastic that scratches with dry tissue.


My unit actually was shipped from Japan


----------



## Ghaunty22

Does anyone know if the USB drivers will work on windows vista? Looks like no as the driver documentation simply mentions windows 7 and up. But hoping yes.


----------



## ShamuellJackson

It's not Vista but I have used it with a Windows 7 tablet for a weekend and it seemed to work. Outside of the experience of using Windows 7 on a tablet that is.

Also I have cleaned the face of my unit many times without any visible scratches I can really see. My kid gets his greasy hands on it a lot so i'm wiping it down about every other week and I bought this around a year ago I think.


----------



## Makiah S

Hmm had some issues finding this via basic search on Head Fi. Non the less!! 







Spoiler: Full Res Pics



  



That said my first impression of the HP-A4BL with another Modded Fostex is that it's a little noisy and a lacking some power.

With music that was mastered at what I'd consider an average level I could get to a max of 87 dBs with music and 64 dBs with pink noise from the balanced output. The Single Ended output was about 3 dBs quieter.

Now with music that is mastered at what I'd consider a below average level, such as some classical, I could get to a max of about 77 dBs... and at max output there was a bit more noise than I care'd for to be 100% honest.

That said I feel it's certainly not the most capable amplifier especially driving something like a modded Fostex Planar. As I frankly expect any amplifier to be capable of outputting any music at *max* of at least 88 dBs. Granted many of you don't listen that loudly, and for a lot of genres I don't. But I do like listening to heavy metal at around an _average of like 87 dBs_ and some of those tracks are mastered at average levels, some above average and others below average. An I'm talking about an average here, so that includes peaks of 93ish dBs and dips as low as 78 or so. An some of my favorite albums/tracks really do have a dynamic range of 15+ dBs and unfortunately this won't be the amp to enjoy them with!!!

So not being able to enjoy all of the music in my library at a slightly above "reasonable" level is a little disappointing.

However on a positive note when switching into my Vintage AKG K240 1980's M Series I found the output to be more than sufficient! Which is fairly impressive as that's a dynamic with around 700 Ohms Impedance!!! I also enjoyed the difference the "filter" switch made with both the Blue and my K240 M

That said, I'll have some more specifics for the unit later this week!


----------



## HungryPanda (Nov 11, 2018)

Did you use high gain? Also was your source at full volume.


----------



## Makiah S

HungryPanda said:


> Did you use high gain? Also was your source at full volume.



Really..., *sigh* yes my source was at fully volume. An yes I did use High Gain

Simply put it's an under powered amplifier... I've got a dozen products to compare it too and quality aside, the balanced HP A4BL just lacks power. 

But I'll have a full review of it here shortly and I'll be sure to include some details on my review process since it's needed apparently


----------



## HungryPanda

A simple question as I use it and it can drive my Fostex T60rp no problem, also my Audeze LCD X


----------



## Makiah S

HungryPanda said:


> A simple question as I use it and it can drive my Fostex T60rp no problem, also my Audeze LCD X



very true, but yea the LCD X isn't to hard to drive compred to the T50 RPs. Even my preFazor LCD 2 get's "louder" than the T50RPs from this unit. And with "average" mastered stuff it does fine. 

Still with some of my quite'r mastered material struggles on the HP A4BL


----------



## HungryPanda

I understand the 24 and 32 bit files I have are all much quieter than regular 16 bit flac files


----------



## Makiah S

HungryPanda said:


> I understand the 24 and 32 bit files I have are all much quieter than regular 16 bit flac files



File format isn't as important 

Dynamic range is where you'll run into issues. My quietest tracks have a dynamic range of like 16 dBs, it's with those songs that the HP A4BL struggles, which is a shame as that music is what I really enjoy the most when I'm in the mood for a very intensive and focused listen!


----------



## GU1DO

Mshenay said:


> Hmm had some issues finding this via basic search on Head Fi. Non the less!!
> 
> 
> 
> ...


Do you use balanced cable ?
i dont have this amp but from what i understand , its a balanced amp which give its best with balanced cable .
but anyway for such headphone i don't think this amp is the best choice , i have argon mk3 and it is very heavy headphone.


----------



## Makiah S

GU1DO said:


> Do you use balanced cable ?
> i dont have this amp but from what i understand , its a balanced amp which give its best with balanced cable .
> but anyway for such headphone i don't think this amp is the best choice , i have argon mk3 and it is very heavy headphone.



Yup, I listed the output for both the balanced output an single ended. An yes I had a balanced cable for balanced output

Additionally at the price point I expect a fully balanced design to handle planars like the T50RP, given how wide spread and popular they are. That an while it is a difficult load I don't think its too uncommon

Plus even my Fiio E17 could get the Talos V2 louder single ended...

It's not like I'm expecting it to power an HE 4/6 

So quality aside, if the E17 can do it as a portable I expect a fully balanced desktop dac/amp to at least be capable of producing similar output


----------



## davehutch

A favour needed please somebody...
I haven't been using my Fostex a great deal lately and since the last time I used it I was on Mac OS High Sierra.
All worked fine.
However, now I'm on Mojave and I did what I often do which is to play iTunes through the DAC and also through one or two Airplay devices at the same time. I can then put on/take off my headphones and wander around the house and still listen to the music without constantly connecting/disconnecting devices.
Problem!...the DAC audio is behind everything else by about half a second  (before you ask, there are no audio delay system settings on a Mac)

If I do the same thing but play through the internal speakers and a couple of Airplay devices, all is well. I've also tried both USB outputs.
Can anyone confirm whether they also have this issue with the latest firmware for the Fostex and Mac OS Mojave 10.14.1 please?

Just to be clear, this is not an issue with my Grace Design m9xx over USB, nor with either of the DACs using Toslink.

I've written to the UK distributor but wanted to ask on here as well so I have more info.

Thanks in advance.


----------



## Yevgen Chupak

try to check your audio midi settings and set up there anything that is greater than 44kHz and check your delay


----------



## davehutch

Yevgen Chupak said:


> try to check your audio midi settings and set up there anything that is greater than 44kHz and check your delay



Thanks, there are no delay setting in Midi Setup and I'm using 44.1KHz


----------



## Yevgen Chupak

i never told u to check delay settings there is none )) try to switch to 192kHz and see if there is any fix to your problem


----------



## Yevgen Chupak

just switch to greater number and check


----------



## davehutch (Dec 4, 2018)

Ah, I'm sorry. I had to guess what you meant in your reply as your English isn't perfect. My mistake.
I've done some more tests including your suggestion of changing the sample rate and it now looks like the issue is being caused by the SonarWorks True-Fi software.
I've therefore contacted the developers for a response.
Thanks for your suggestion.


----------



## HungryPanda

I also had to uninstall truefi as it caused my foobar to crash


----------



## B.inthe6ix

Has anyone attempted to remove the top plate of the unit? The screws seem to be set with loctite but I'm not sure why they would do this other than to discourage tampering. I'd like to be able to deoxidize the switches in the future but need to get the top off . Any insight would be greatly appreciated. Thanks in advance.
B.


----------



## Dartin Bout

B.inthe6ix said:


> Has anyone attempted to remove the top plate of the unit? The screws seem to be set with loctite but I'm not sure why they would do this other than to discourage tampering. I'd like to be able to deoxidize the switches in the future but need to get the top off . Any insight would be greatly appreciated. Thanks in advance.
> B.


I also am very interested in "popping the top". In an earlier comment, someone mentioned the opamps that were set in an IC buss that may make them replaceable.. I tried to unscrew thee top and the screws  resisted moderate effort and seemed to threaten the integrity of the philips screw heads. I'd love to hear from somebody who get them off. I have some Burston, Muse and NS opamps I'd like try, I'd even be amenable to leaving the top off if I could get Asio\DSD's out the balanced port into my HD650's.  If someone from California could help, there might be a gift card from their local "recreational" dispensary in it for them.


----------



## B.inthe6ix (Dec 29, 2018)

Upon examination you will notice that the screws appear as philips head but are in fact very shallow cross grove with vertical side wall. In other words you would require a specialty tool or a philips driver that has it's tip ground down, as a makeshift tool. If you try to use a standard philips driver, it will just spin out & destroy the screw so it will need to be drilled out. Fostex has chosen a screw that requires a specialty driver so as to discourage customer tampering. I'm almost certain that a *loctite* has also been used. Heating is the standard option for loosening this treatment but it would be foolish to risk that approach IMO. A proper driver is the only sensible answer I suspect. How & where is the question. IF warranty is of no concern & you can live with permanent alteration, one could drill out the screw heads & have a top that was lift out or replaced with small pieces of carpet tape for temporary hold down.
B.
Edit: There may be methods of heating the screw head in a safe manner. Eye glasses frames are often heated for bending. Heating the screw driver tip in this way may loosen the loctite bond if held in the head groove for a short time. Perhaps as a last resort.

Edit #2 : I found this which may be the needed info.


----------



## JerkChicken

My HP-A4BL has fed my th900mk2 at more than "reasonable" listening levels however it does not power my newly acquired Ether 2's 

I thought it would be fine but i guess its not even umph for these planars :/


----------



## davehutch

Balanced or unbalanced?


----------



## JerkChicken

davehutch said:


> Balanced or unbalanced?


I have the balanced version.


----------



## davehutch

JerkChicken said:


> I have the balanced version.


That’s surprising. Balanced output should have enough power. I’m at about 2 o’clock for the Senn HD650s


----------



## JerkChicken

That was about the same with my th900mk2 and my hd660s.

The ether 2 though is just a different beast apparently. Might be more sensitive and being a planar driver it’s just power hungry


----------



## davehutch

Good to know. When I was choosing the Fostex I managed to try it first but only on the HD650s. My second choice was the Klipsch Heritage, which, on paper, looks to have more power.


----------



## Dartin Bout

B.inthe6ix said:


> Upon examination you will notice that the screws appear as philips head but are in fact very shallow cross grove with vertical side wall. In other words you would require a specialty tool or a philips driver that has it's tip ground down, as a makeshift tool. If you try to use a standard philips driver, it will just spin out & destroy the screw so it will need to be drilled out. Fostex has chosen a screw that requires a specialty driver so as to discourage customer tampering. I'm almost certain that a *loctite* has also been used. Heating is the standard option for loosening this treatment but it would be foolish to risk that approach IMO. A proper driver is the only sensible answer I suspect. How & where is the question. IF warranty is of no concern & you can live with permanent alteration, one could drill out the screw heads & have a top that was lift out or replaced with small pieces of carpet tape for temporary hold down.
> B.
> Edit: There may be methods of heating the screw head in a safe manner. Eye glasses frames are often heated for bending. Heating the screw driver tip in this way may loosen the loctite bond if held in the head groove for a short time. Perhaps as a last resort.
> 
> Edit #2 : I found this which may be the needed info.


I tried again over the weekend and managed to extract the 6 screws and the volume knob . I found only one opamp and replacing it with a Muse only seemed to affect the SE output. It sounded very constrained all through the mid-range. I didn't try one of my Burston V6 Classic's as I didn't feel inclined to pull it from my current sound card.


----------



## TeknicalXtacy

If I am connecting my HP-A4BL to my audio source with a optical cable, do I need to update the firmware?  That is assuming the version currently on the device is not up to date to begin with.

Thanks,
john


----------



## skingg

TeknicalXtacy said:


> If I am connecting my HP-A4BL to my audio source with a optical cable, do I need to update the firmware?  That is assuming the version currently on the device is not up to date to begin with.
> 
> Thanks,
> john


Can't be sure if you need to update the firmware if you hook it up with an optical cable although I would assume it isn't required. I've purchased mine new last April from Bic Camera Japan and it does not have the latest firmware out of the box.


----------



## HungryPanda

Be careful when you do update, I managed to slip the micro sd card between the bottom of case and sd slot and it just slipped in. I had to open case to get it out


----------



## TeknicalXtacy (Jan 3, 2019)

Thanks for the feedback folks.  Initially thought the seller cancelled my order.  But I received my HP-A4BL on Wednesday.  I am using it with my new TH 610's.

A couple of items.

1. So I take it that updating the firmware is a good idea, regardless of connection type (while be careful to insert properly).

2. I have not downloaded any Fostex drivers, assuming that optical negates the need and that the drivers are for USB only (right?)

3.  There are several driver types.  ASIO is quite loud, but gets interference when opening Google - very odd.  WASAPI (Exclusive) seems to provide the same level of audio quality without the interference.

4. Current settings in Music Bee:
a. Output - WASAPI (Exclusive)
b. Sound Device - S/PDIF Pass-through Device (2-ASUS XONAR Essence STX)
 - I am using a optical cable connected to the SPDIF on the STX card.

5.  Balanced cables ordered today.  What can I expect in sound signature compared to SE?

Any advice/comments greatly appreciated.

Thanks,
john


----------



## B.inthe6ix (Jan 4, 2019)

As with firmware updates in most devices (cameras included), it is always wise to double check the procedure from their website so as to avoid possible damage, or at worst - bricking the unit. Be sure to use the recommended SD card type etc. When my dealer attempted to update mine,(to ensure compatibility for my Mac), he realized after having difficulty getting acknowledgement of successful update, that the unit already had the latest update. (just in case you have the same result)
B.


----------



## TeknicalXtacy

B.inthe6ix said:


> As with firmware updates in most devices (cameras included), it is always wise to double check the procedure from their website so as to avoid possible damage, or at worst - bricking the unit. Be sure to use the recommended SD card type etc. When my dealer attempted to update mine,(to ensure compatibility for my Mac), he realized after having difficulty getting acknowledgement of successful update, that the unit already had the latest update. (just in case you have the same result)
> B.



Thanks for the advice.  I did research before purchasing so I am familiar, in theory, with the update process.  Fostex has a multi-page pdf on the process, which I am sure often does not always go as smoothly as new owners would hope.

I am currently trying to learn some of the more technical aspects of getting the most out of the unit.  As with most things in this hobby, some things seem more like a religion then science.  But I will continue to read and try to optimize the units capabilities.

Thanks again,
john


----------



## B.inthe6ix (Jan 4, 2019)

^^^
Sounds like you have a handle on it. All the best in your endeavor. I, for one am extremely happy with this unit's quality of producing an exquisite sound  & with it's practical switching options. The build quality & design is outstanding. Let us know of any discoveries as to enhancement you may come across.
B.


----------



## Nostoi

I am looking into the HP-A4BL as a balanced option to go with my HP-V1. Apologies if this has already been covered, but does anyone have a sense of how the HP-A4BL compares to the Chord Mojo of the IFI iDSD Micro? For that matter, has anyone paired it withr the HP-V1? Thanks!


----------



## KingFiercer

For fun tried MUSES8920 opamp. Less lower bass, bumped midbass, mids have less body, highs are slightly highlighted. Defalut OPA2134 remains the best, balanced fullbodied sound. 1.5 years after purchase still love this DAC


----------



## aqtaket

Very interesting dac/amp. Nice option to hook up a smaller DAP via USB OTG. Subscribed.


----------



## aqtaket

Hello, guys, I have a question about the balanced output of this Fostex. I will need to re-terminate my Audio-Technica ATH-AD2000X with a XLR 4 pin plug. There are 4 cores in the stock cable and it doesn't look and feel bad.
Is the pinout like on this pic? And the view is like from the front panel (I mean, I'll have to solder the wires exactly like on the diagram, it is not a mirror image, right?)


----------



## davehutch

aqtaket said:


> Hello, guys, I have a question about the balanced output of this Fostex. I will need to re-terminate my Audio-Technica ATH-AD2000X with a XLR 4 pin plug. There are 4 cores in the stock cable and it doesn't look and feel bad.
> Is the pinout like on this pic? And the view is like from the front panel (I mean, I'll have to solder the wires exactly like on the diagram, it is not a mirror image, right?)



This should help. I used the info to make my 4-pin extension and re-terminate my Sennheiser cable to fit the Fostex
https://robrobinette.com/BalancedCable.htm#Sennheiser_HD


----------



## aqtaket

davehutch said:


> This should help. I used the info to make my 4-pin extension and re-terminate my Sennheiser cable to fit the Fostex
> https://robrobinette.com/BalancedCable.htm#Sennheiser_HD


Thank you very much!
Now it makes sense... "_Remember the pin numbers will be opposite shown when viewing the rear of the connector when soldering" - _now I understand.


----------



## Benleetv

I was thinking of getting the HP-A4BL for my pair of meze 99's and m1060c's. I also want to get balance cables that end in 4 pin xlr for both so i can use the xlr output on this amp/dac.so, finally my questions: does the amp part have enough to power the m1060c's? I know planar headphones can be harder to power. Also, does the balance output effect the sound? And if anyone owns these headphones and this unit, do you think they pair well with it and in balanced? Thanks in advance!


----------



## HungryPanda

I have the HifiMan HE560, HE400i and Audeze LCD-X (Balanced) and my HPA4BL can drive them all fine


----------



## Benleetv

HungryPanda said:


> I have the HifiMan HE560, HE400i and Audeze LCD-X (Balanced) and my HPA4BL can drive them all fine



Thank you for the fast response and have you tried them single ended? Is balance worth it?


----------



## aqtaket

Another quick question to the happy owners of this wonderful Fostex unit:
If I hook up a DAP vis USB OTG cable+ the Fostex USB cable supplied, will it supply power to the DAP (and charge it) from its USB 2.0 port, or this port is only meant for data transfer?


----------



## HungryPanda

As far as I know the USB is only for connection to computer


----------



## aqtaket

HungryPanda said:


> As far as I know the USB is only for connection to computer


So it wouldn't work with a DAP via OTG? Even if a DAP supports transferring data via USB OTG?


----------



## HungryPanda

I have never tried so cannot advise


----------



## davehutch

Having an issue...
I bought an adaptor from Drop.com, the balanced XLR to 2.5mm, so that I could use my IEMS. However I get small electric shocks (tingles) from the metal shells of my IEMs.
Any idea what's going on? I have a multimeter and if I measure between the left and right shells, there's about 19V.
I should also add that I'm using optical in to the amp
Can anyone help please?


----------



## aqtaket

davehutch said:


> Having an issue...
> I bought an adaptor from Drop.com, the balanced XLR to 2.5mm, so that I could use my IEMS. However I get small electric shocks (tingles) from the metal shells of my IEMs.
> Any idea what's going on? I have a multimeter and if I measure between the left and right shells, there's about 19V.
> I should also add that I'm using optical in to the amp
> Can anyone help please?


There are differenr pinouts for 2.5mm balanced. The so-called "European", "Asian", "Fiio", "AK"....
Looks like the pin-out of your adapter does not match the one of you male-jack in the phones..


----------



## davehutch

aqtaket said:


> There are differenr pinouts for 2.5mm balanced. The so-called "European", "Asian", "Fiio", "AK"....
> Looks like the pin-out of your adapter does not match the one of you male-jack in the phones..


I also made my own adaptor cable and I get the same issue. Fostex distributor, SVC are assisting but there doesn't seem to be a pattern to it. If I measure between pins 1 and 3 I get 1 or 2 millivolts, which is fine.
Same between pins 2 and 4
Yesterday I plugged in and for a while it was all fine, but then I started getting shocks again.

Can anyone else with metal bodies IEMs let me know if they experience the same issue?


----------



## aqtaket

This Fostex has only one DAC chip, but a balanced amplification part, is that correct?
If so, that seems a bit strange to me, a balanced DAC/amp should have two DACs and two amps for true balance. What Gives balanced output in this case? Only higher power?


----------



## selvakumar

hi i tried all burson opamps v5i,v6c,v6v


----------



## dsnedeco (Sep 2, 2019)

Can someone explain to me exactly how to* uninstall* the HP-A4 usb driver and *install* the HP-A4BL usb driver on Windos 10.  I have been unable to do that. I have downloaded "FOSTEX_USB_Audio_Driver_V221.zip"  It seems like no matter what I do I end up with the HP-A4.  It works OK but it is not the HP-A4BL.  Some where along the line months ago I had it installed.  But then my computer crashed and I can't seem to get it back.


----------



## davehutch

davehutch said:


> I also made my own adaptor cable and I get the same issue. Fostex distributor, SVC are assisting but there doesn't seem to be a pattern to it. If I measure between pins 1 and 3 I get 1 or 2 millivolts, which is fine.
> Same between pins 2 and 4
> Yesterday I plugged in and for a while it was all fine, but then I started getting shocks again.
> 
> Can anyone else with metal bodies IEMs let me know if they experience the same issue?



*Update*
Fostex sent me an earthed power supply. All is now fine


----------



## HungryPanda

Glad to know all is fine


----------



## gimmeheadroom

davehutch said:


> Especially when you look at the original images of the Klipsch when it was first shown:
> http://www.avsforum.com/klipsch-tea...er-ear-headphones-and-usb-dacamp-at-ces-2017/
> and
> https://smart-sound.jp/stuffblog/blog/klipsch-heritage



But the Klipsch material says it uses an ESS DAC and this thread seems to say Burr Brown...did anybody track this down?


----------



## RSC08

Anyone tried this amp with the Hifiman Sundara? I'm looking to upgrade my home setup and currently deciding if I should go HP-A4 + Sennheiser HD650 or Hifiman Sundara.


----------



## gimmeheadroom

Sennheiser 600 series are at their best with a tube amp. The Fostex would not be my choice for Sennheisers. I have no idea about the Sundara.


----------



## cdg777

Hey guys, thinking of getting one, does it heat up much? I want to stick it under the desk with some double sticky tape, and wondering if it would stay in place. Cheers!


----------



## selvakumar

cdg777 said:


> Hey guys, thinking of getting one, does it heat up much? I want to stick it under the desk with some double sticky tape, and wondering if it would stay in place. Cheers!


It won't heat much but the heat can be withstand by 3m double sided automotive tape


----------



## Makiah S

cdg777 said:


> Hey guys, thinking of getting one, does it heat up much? I want to stick it under the desk with some double sticky tape, and wondering if it would stay in place. Cheers!


... why? 

Buy  a JDS Labs Atom or EL Amp II for less and get a better product for less...

Or even a Schiit Hersey


----------



## gimmeheadroom

aqtaket said:


> This Fostex has only one DAC chip, but a balanced amplification part, is that correct?
> If so, that seems a bit strange to me, a balanced DAC/amp should have two DACs and two amps for true balance. What Gives balanced output in this case? Only higher power?



You don't need two DACs. The amplifier is a separate thing from the DAC.


----------



## gimmeheadroom

ptolemy2k6 said:


> it drives lcd-3 just fine, so it should drive hd650 easily.  it's a very good amp, IMO. very good sound, little warmish but I like warm.



The LCD-3 and HD 650 are different kinds of headphones. The LCD-3 needs current, the Sennheisers need voltage.



RSC08 said:


> Anyone tried this amp with the Hifiman Sundara? I'm looking to upgrade my home setup and currently deciding if I should go HP-A4 + Sennheiser HD650 or Hifiman Sundara.



The specs look to me that they will not drive the 650s well. I would recommend a tube OTL amp or a strong solid state amp for the Sennheisers.

I'm considering this DAC but I will not use the headamp, I'll plug it into a separate amplifier.


----------



## Makiah S

gimmeheadroom said:


> The LCD-3 and HD 650 are different kinds of headphones. The LCD-3 needs current, the Sennheisers need voltage.
> 
> 
> 
> ...



Why? Topping E30 and or Schiit Modius will both serve as far better dacs. This product wasn't competitive the year it came out and is imo even worse now. I'd maybe pay $100 for it second hand, beyound that it's too costly for how poorly it performs and sounds


----------



## Nostoi

I had this unit when it came out. It's nicely built and I appreciate that it's made in Japan, but it was underwhelming in terms of performance. I imagine most contemporary mid or even low-tier DAPs likely have more sophisticated dac chips than the Fostex.


----------



## gimmeheadroom

Nostoi said:


> I had this unit when it came out. It's nicely built and I appreciate that it's made in Japan, but it was underwhelming in terms of performance. I imagine most contemporary mid or even low-tier DAPs likely have more sophisticated dac chips than the Fostex.



But is it the DAC you don't like or the amp? Splitting hairs between chip dacs is really not very important. Any of them have performance better than anybody can hear. What's important is what happens in the analog section.


----------



## Nostoi (Aug 2, 2020)

gimmeheadroom said:


> But is it the DAC you don't like or the amp? Splitting hairs between chip dacs is really not very important. Any of them have performance better than anybody can hear. What's important is what happens in the analog section.


As far as I can recall - and it's some time ago - the amp portion is seriously underpowered. I think the sound quality of the DAC itself is fine, a Burr Brown if I remember. Of the Fostex units in this generation, the HP-V1 tube amp was and is excellent. Personally I would not use the dac/amp combo myself, and I'm a fan of Fostex.

Edit: it has a maximum output of 300mw, so it would have very limited capability even when used as a line out.


----------



## Nostoi

gimmeheadroom said:


> But is it the DAC you don't like or the amp? Splitting hairs between chip dacs is really not very important. Any of them have performance better than anybody can hear. What's important is what happens in the analog section.


P. S., out of interest - are you affiliated with Head-Fi as a mod or is the link as your website a gesture of support?


----------



## gimmeheadroom (Aug 2, 2020)

Nostoi said:


> As far as I can recall - and it's some time ago - the amp portion is seriously underpowered. I think the sound quality of the DAC itself is fine, a Burr Brown if I remember. Of the Fostex units in this generation, the HP-V1 tube amp was and is excellent. Personally I would not use the dac/amp combo myself, and I'm a fan of Fostex.
> 
> Edit: it has a maximum output of 300mw, so it would have very limited capability even when used as a line out.



Thanks, I was not planning to use the amp section. But if it doesn't run 2V line out that would definitely be a problem. I'll see if i can find specs anywhere.

updated, looks ok based on this https://fostexinternational.com/docs/products/HP-A4BL.shtml#content-3-tab-tab


----------



## gimmeheadroom

Nostoi said:


> P. S., out of interest - are you affiliated with Head-Fi as a mod or is the link as your website a gesture of support?



I'm just a normal member here if that is even possible 

It's a link to a pic of my desktop setup in the headfi thread.


----------



## Nostoi

gimmeheadroom said:


> Thanks, I was not planning to use the amp section. But if it doesn't run 2V line out that would definitely be a problem. I'll see if i can find specs anywhere.


Specs here.


----------



## gimmeheadroom

Nostoi said:


> Specs here.



Thanks, I found it. Looks fine to be used as a DAC only. I'm looking for a desktop DAC for up to 500 euros that does DSD. Not sure what the options are so I was considering this one.


----------



## Nostoi

gimmeheadroom said:


> I'm just a normal member here if that is even possible
> 
> It's a link to a pic of my desktop setup in the headfi thread.


That makes sense now (I should have clicked beforehand). Maybe I missed it, but if you have an RME, what do you need the Fostex for?


----------



## gimmeheadroom

Nostoi said:


> That makes sense now (I should have clicked beforehand). Maybe I missed it, but if you have an RME, what do you need the Fostex for?



I have several DACs including the RME, the Brooklyn DAC+, and an Oppo 205. But I also have more than one apartment and the battery on my Chord Mojo is dying after almost 4 years. I want to get a cheap but good desktop DAC that doesn't need a battery.


----------



## 340519

gimmeheadroom said:


> I'm just a normal member here if that is even possible
> 
> It's a link to a pic of my desktop setup in the headfi thread.


Lol normal.


----------



## Rickster1515

Hi All

I am new here, i actually interested with Fostex HP A4BL, but i use my Ipad pro for music playing, can i connect my Ipad to this dac/amp via usb input? Do i need to update the software if i use my ipad?
Thanks


----------



## Yevgen Chupak

Rickster1515 said:


> Hi All
> 
> I am new here, i actually interested with Fostex HP A4BL, but i use my Ipad pro for music playing, can i connect my Ipad to this dac/amp via usb input? Do i need to update the software if i use my ipad?
> Thanks



iPad has headphone jack. So you can use 3.5.mm to Single-Ended input on Fostex.


----------



## KingFiercer (Oct 22, 2020)

Fostex has no analog inputs, only RCA line out and headphone outs. Inputs are only optical toslink and USB. USB can work through OTG with android devices, but I don't know about Apple. By the way, I like the sound from the computer with Win10 more than from the android smartphone. I think using bluetooth in iPad to connect to bluetooth DAC (something like TOPPING DX7 Pro) is not a bad option.


----------



## Rickster1515

KingFiercer said:


> Fostex has no analog inputs, only RCA line out and headphone outs. Inputs are only optical toslink and USB. USB can work through OTG with android devices, but I don't know about Apple. By the way, I like the sound from the computer with Win10 more than from the android smartphone. I think using bluetooth in iPad to connect to bluetooth DAC (something like TOPPING DX7 Pro) is not a bad option.


----------



## Rickster1515

I finally had a chance to try the HP A4BL at my local shop. I use the iphone X connected to the Usb In and it works fantastic. Clear sounding and tonally balance. The balance xlr is indeed amazing with the small dac amp and balance output. Love this little unit.


----------



## Audioboxer (May 2, 2021)

Hi everyone, I know this topic hasn't been bumped in a while but as a recent owner for the HP A4BL I have a question about speaker popping when using USB.

I have my PC connected via USB and a set of Edifier speakers and headphones coming off the Fostex. Everything with the headphones is fine. The speakers however have an issue with the passive speaker out of the powered pair making loud pops any time windows volume is changed, or there is a windows sound or even when skipping through a youtube video. It happens with an older set of powered Yamaha speakers I have as well.

I went and bought a powered USB hub and then also a USB cable with double ferrites on it. Still doing the same thing with the left speaker (passive one). I have an AV Link ground loop isolator coming today I'm going to add between the phono output from the Fostex that goes into the speakers. Last thing I have to try.

Does this sound like a grounding issue, or is it something else to do with phono output going to powered speakers?

Optical obviously works fine, but I'd rather crack the USB conundrum if I can lol.

Cheers!


----------



## davehutch

Audioboxer said:


> Hi everyone, I know this topic hasn't been bumped in a while but as a recent owner for the HP A4BL I have a question about speaker popping when using USB.
> 
> I have my PC connected via USB and a set of Edifier speakers and headphones coming off the Fostex. Everything with the headphones is fine. The speakers however have an issue with the passive speaker out of the powered pair making loud pops any time windows volume is changed, or there is a windows sound or even when skipping through a youtube video. It happens with an older set of powered Yamaha speakers I have as well.
> 
> ...


I'm just throwing this out there because it rings a small bell with me about a potential grounding issue. I had a static discharge issue when using metal IEMs so I wrote to Fostex (my UK dealer) and they sent me a grounded power supply. Issue solved.
Here's a phot of PS if that helps at all


----------



## Audioboxer (May 2, 2021)

davehutch said:


> I'm just throwing this out there because it rings a small bell with me about a potential grounding issue. I had a static discharge issue when using metal IEMs so I wrote to Fostex (my UK dealer) and they sent me a grounded power supply. Issue solved.
> Here's a phot of PS if that helps at all



Oh, good idea. My UK plug from them has ferrite cores wrapped around both sides, but it's not a grounded power supply. I purchased from Amazon so I dunno if Fostex UK will send anything. Maybe with an invoice.

Can you let me know the email/site you used for contacting them? https://www.fostexinternational.com/docs/distributors/index.php?group=Europe There is a UK based email here.

I'll update on whether the isolator does anything later when it arrives.


----------



## davehutch

Audioboxer said:


> Oh, good idea. My UK plug from them has ferrite cores wrapped around both sides, but it's not a grounded power supply. I purchased from Amazon so I dunno if Fostex UK will send anything. Maybe with an invoice.
> 
> Can you let me know the email/site you used for contacting them? https://www.fostexinternational.com/docs/distributors/index.php?group=Europe There is a UK based email here.
> 
> I'll update on whether the isolator does anything later when it arrives.


I'm in the UK and spoke to a guy called Nigel at fostex@scvdistribution.co.uk
He needed the serial number of my amp so sounds like they were changed at some point. Best of luck


----------



## Audioboxer (May 2, 2021)

davehutch said:


> I'm in the UK and spoke to a guy called Nigel at fostex@scvdistribution.co.uk
> He needed the serial number of my amp so sounds like they were changed at some point. Best of luck



Mine came pre-loaded with firmware 1.10 (it's written on the box), so I don't know if that is classed as the _latest_ batch. The plug does have a ferrite core wrapped at the plug base and another at the end going into the unit. So either they've upgraded to this plug or I presume your original plug was like this?

I'll email them anyway. Still waiting on my Amazon delivery to test the isolator. If it works it works, but I'll still see if I can snag another plug.

*edit* - lol the AV isolator from Amazon makes things worse?! So thats going back. It introduces hum and noise that wasn't there before. Head-scratching. I'll see if I can get another plug.


----------



## davehutch

Audioboxer said:


> Mine came pre-loaded with firmware 1.10 (it's written on the box), so I don't know if that is classed as the _latest_ batch. The plug does have a ferrite core wrapped at the plug base and another at the end going into the unit. So either they've upgraded to this plug or I presume your original plug was like this?
> 
> I'll email them anyway. Still waiting on my Amazon delivery to test the isolator. If it works it works, but I'll still see if I can snag another plug.
> 
> *edit* - lol the AV isolator from Amazon makes things worse?! So thats going back. It introduces hum and noise that wasn't there before. Head-scratching. I'll see if I can get another plug.


Does sound more like a grounding issue. My mains plug is a full 3-pin plug with all pins (inc. each) metal. An IEC connector connects to the transformer unit.


----------



## Audioboxer (May 3, 2021)

davehutch said:


> Does sound more like a grounding issue. My mains plug is a full 3-pin plug with all pins (inc. each) metal. An IEC connector connects to the transformer unit.



Yeah I emailed them about a plug, so we'll see if they can send me one 

While it's the 'wrong' thing to do, I plugged my speakers into the headphones output and there is no speaker pop. So it's just coming off the phono output from the Fostex. I guess that's to be expected though as I don't have any issues with headphone usage.

For anyone who understands audio and hardware a LOT better than a newbie like myself, is this because the phono output is more powerful or something? Or more susceptible to grounding issues? As my speakers are active and no external amp is being used I presume the Fostex being powered and my speakers being powered is where the grounding issue is occurring.

I'm enjoying learning more about grounding issues, ferrite cores, audio humming/buzzing and more but at the same time it's a massive headache for a newbie that up until now when it comes to PC audio use I've only ever engaged with motherboard sound output (or a few years ago now I had a dedicated Xonar soundcard).

Never really had any issues with audible hum, buzz or pops with TV sound systems or even my record player that's hooked up to a Cambridge Audio amp and Roth speakers.

Bought this DAC for headphone use on PC as part of a big PC upgrade I done earlier this year, so it's been my first real headache with audio. I mostly use headphones but the pop on the passive speaker when not using headphones is just that annoying. It's a right piercing sound that is pretty unpleasant 

My PC speakers aren't the most expensive, being a mid-range Edifier pair which only cost not too far north of £100, but for me it's enough as PC speaker use will mostly just be the odd YouTube video or the likes. They have a subout so I was planning on adding a sub in the not to distant future just to improve the lows a bit. Until then though I want to figure out how to sort this issue I have between the Fostex and the speakers. As I mentioned earlier I tested things with a Yamaha NX-50 powered set of speakers my PC audio was running through for the last few years and those too had the popping issue. So it's not as if my Edifier low-end speakers are faulty or anything. No pops from them either when hooking up to the motherboard sound directly.

What I find interesting and I have no knowledge of why it happens is the speaker popping only happens with the left speaker. On both the Edifier and Yamaha sets I have tried that is what I'd call the passive speaker. The right speaker is powered, where the volume control and power control is. A single phono output is used to connect the left speaker to the right. I guess that's just how it can happen? Is it anything to do with the passive speaker being the last "item" in the chain???


----------



## Audioboxer (May 3, 2021)

I managed to scramble together some odds and ends power supplies/plugs from around the house off of other devices. Every single one of them still results in the passive speaker with a big pop any time a YouTube video is seeked through, or sound first comes out the speaker. None of my power supplies are rated as powerful or the same as the one dave posted above though.

Still, making me doubt if it's even the power supply now... Has anyone else got powered speakers hooked up to the phono outputs on this DAC? I genuinely think I've done everything I can at the PC end from getting a powered USB hub to using a ferrite attached USB cable.

The troubleshooting for me comes at the phono out point, there is no issue at all using headphones with the DAC over USB. Optical is obviously fine with headphones AND speakers. But I've read that before now, any issues with all of this just use optical...

I don't know enough about any of this to have experience to know if its the power supply, USB or something else. Optical works fine which makes me think its USB, but I've tried hooking up an AV isolator and it just made things worse. Most people online say when they went to an external USB hub it did the trick. Would rather not spend £50 on this and it's not USB https://www.amazon.co.uk/iFi-iDefen...rds=usb+noise+isolator&qid=1620053951&sr=8-18

I've hooked everything up via my laptop when it has its power coming from battery and I still have the issue.

What makes me more confused is most people online talk about hum and buzz when its a ground loop issue. My issue is a very sharp loud pop noise that comes out of one speaker only, the passive speaker in the powered speaker setup. As tested this is across two different powered speaker brands.

My PC and laptop are Windows 10 so it's not like I can try Mac over USB. My phone is a Galaxy S20 and I gave it a brief go hooking up over USB via a USB A to C adapter but I couldn't figure out how to make sound pass through the Fostex over USB or even know if it's possible with an Android/Galaxy phone (I read someone else mention doing it with an iPhone).

I wouldn't rule out something being faulty in my HPA4-BL phono outputs, but I don't _think_ it's that.


----------



## davehutch

@Audioboxer I’m curious what happens if you swap the left and right outputs from your Fostex?  Does the pop stay with the ‘slave’ speaker?


----------



## Audioboxer (May 3, 2021)

davehutch said:


> @Audioboxer I’m curious what happens if you swap the left and right outputs from your Fostex?  Does the pop stay with the ‘slave’ speaker?



Fantastic question, I had done just about everything apart from this LOL

That switches the pop to the right speaker, what I'll refer to as the active.

Got me worried this means it might be my Fostex unit that has a faulty phono output???


----------



## davehutch

Potentially, but it also could be the way your PC switches the USB audio, in addition to a grounding problem. For what it's worth, Fostex sent me the new power supply free of charge so let's see what they say.
Swapping connectors and items in the chain, as you obviously are already aware, is the best way to fault-find. If you have access to another PC that might at least rule out software and USB drivers until you hear back from Fostex. My understanding is that a properly earthed power supply would have no 'dummy' pins so the three mains plug pins would all be metal, the cable would be 3-core (all wires connected) and the IEC connector would have three holes. Is that the case with yours?


----------



## davehutch

Also, have you tried different USB outputs on your PC?


----------



## Audioboxer (May 3, 2021)

davehutch said:


> Potentially, but it also could be the way your PC switches the USB audio, in addition to a grounding problem. For what it's worth, Fostex sent me the new power supply free of charge so let's see what they say.
> Swapping connectors and items in the chain, as you obviously are already aware, is the best way to fault-find. If you have access to another PC that might at least rule out software and USB drivers until you hear back from Fostex. My understanding is that a properly earthed power supply would have no 'dummy' pins so the three mains plug pins would all be metal, the cable would be 3-core (all wires connected) and the IEC connector would have three holes. Is that the case with yours?



Nah it's a dummy pin plug, or that's what I think you mean with one pin being plastic. It's a Unifive UNK318-1215 12V 1.5A. It's quite like this except 3 prong https://www.unifive.com/products/category/standard/18w/un318.html There is no 'power brick' as I call them (what you showed me on the last page), it's just a plug with some ferrites along the wire.

I've tried on my laptop and still have the issue. The laptop is Windows 10 like my PC. I tried hooking up my Galaxy S20 and while the phone seems to pickup the Fostex and the Fostex responds by appearing to acknowledge it, I can't get any sound. But this might be an Android/Samsung issue and/or I just don't know how to do audio over USB to a DAC with Android. I read someone on here had an iPhone hooked up and working but unless I go borrow an iPhone off a mate or family I can't quickly check that.

Yeah here is hoping a proper earthed power-supply helps.



davehutch said:


> Also, have you tried different USB outputs on your PC?



Yeah, it's the first thing I did. I went and bought a powered USB hub as well to see if that helped after reading advice. It doesn't, but the hub is quite a decent thing to have so no issues just keeping it.


----------



## davehutch

Audioboxer said:


> Nah it's a dummy pin plug, or that's what I think you mean with one pin being plastic. It's a Unifive UNK318-1215 12V 1.5A. It's quite like this except 3 prong https://www.unifive.com/products/category/standard/18w/un318.html There is no 'power brick' as I call them (what you showed me on the last page), it's just a plug with some ferrites along the wire.
> 
> I've tried on my laptop and still have the issue. The laptop is Windows 10 like my PC. I tried hooking up my Galaxy S20 and while the phone seems to pickup the Fostex and the Fostex responds by appearing to acknowledge it, I can't get any sound. But this might be an Android/Samsung issue and/or I just don't know how to do audio over USB to a DAC with Android. I read someone on here had an iPhone hooked up and working but unless I go borrow an iPhone off a mate or family I can't quickly check that.
> 
> ...


OK. If I think of anything else I'll write in. Fingers crossed


----------



## Audioboxer (May 3, 2021)

davehutch said:


> OK. If I think of anything else I'll write in. Fingers crossed



Thanks.

One question I could throw at you is would a grounding problem not manifest itself over an optical connection? I know the answer to many pops, crackles and hums is "just use optical", but I don't know the science behind why that works 

Also, I presume a grounding problem might not manifest through the headphone output? That's the one I'm a bit more miffed by. Audio over USB through headphones is fine, great even. The reason I wanted to buy a DAC like this! At least on the three pairs of headphones I've tested with (no balanced yet, those will come with a headphones upgrade later).

*edit* - In the meantime I'm giving up and using optical. Hope Fostex can hook me up with a quality grounded power supply. I kind of nuked my own worry that the phono output was faulty on my unit by plugging optical back in. The phono out is still used to go to the speakers even if its optical bringing audio in, and everything works great over optical. So it really does have to either be a power supply grounding fault or a USB issue. I'm not against using optical it's just frustrating as hell to buy a USB DAC and not be able to figure out why you're getting really bad feedback/pops over USB  24bit/96k is more than enough for me, heck, it's overkill anyway I just use my PC for listening to music, working and occasionally some light gaming. But your issues being fixed by another power supply gives me hope.


----------



## davehutch

Audioboxer said:


> Thanks.
> 
> One question I could throw at you is would a grounding problem not manifest itself over an optical connection? I know the answer to many pops, crackles and hums is "just use optical", but I don't know the science behind why that works
> 
> ...


I don't know the answer to that one I'm afraid. I'm only going by hunch and my own experience but I don't know the electrical theory I'm afraid. My own issue was a small electrical shock from my IEMs, whether or not I used USB or optical input to the Fostex. Fostex were very helpful and fast too.


----------



## Audioboxer

davehutch said:


> I don't know the answer to that one I'm afraid. I'm only going by hunch and my own experience but I don't know the electrical theory I'm afraid. My own issue was a small electrical shock from my IEMs, whether or not I used USB or optical input to the Fostex. Fostex were very helpful and fast too.



Gotcha, much appreciated with all the advice and things to try. The one thing we have discovered is the plug I have has the fake prong, so it's one of the last avenues I have left for trying.

The internet is full of people having issues with DACs and USB, so it seems like it's a minefield. Many issues do seem to be sorted with a powered external USB hub. Something which I have tried.

Until I hear back I'll just use optical!


----------



## Audioboxer

Just a small update to say Fostex customer service UK are great



> In the first instance I can send you a grounded power supply which may well correct the problem please confirm your full address & contact number.



Here is hoping my USB issues get fixed! Just been running optical in the mean time with no issues.

I guess I should probably add I love this wee DAC too


----------



## davehutch

Audioboxer said:


> Just a small update to say Fostex customer service UK are great
> 
> 
> 
> ...


Yes, they certainly are. Here’s hoping


----------



## Audioboxer (May 10, 2021)

davehutch said:


> Yes, they certainly are. Here’s hoping



Arrived today, sadly it doesn't help, so I'm all out of ideas. I guess I would need to now troubleshoot by means of trying some sort of input that isn't my own laptop/PC to test if it's all to do with the USB source. I've tried getting my Galaxy S20/Nintendo Switch outputting audio with a USB C converter but neither seem to work.

That and/or getting another set of speakers and testing them. I only have two pairs that are powered speakers, both exhibit the same issue. I don't think it's the speakers though as they work fine over optical.

So props to Fostex for supplying a grounded power supply, but I'm no closer to finding out why one of the phono outputs on the Fostex seems to deliver a sharp pop to whatever speaker its connected to when it's over USB. A pop on power on, and then pops during certain operations like moving the YouTube seek bar or if there is no audio output for a while, the next time there is (easily demonstrated with having nothing playing and moving the windows control taskbar volume slider).

I have been reading a load of horror stories across the web where people just struggle to get USB working without a whole host of issues. Some saying its even down to the fault of Windows 10.

Optical has been working fine the past few days, so if all else fails I'll just stick with it. I still appreciate the plug anyway, it rules out any future issues like yours.


----------



## Audioboxer

While I've had no luck with USB and have now just stuck with optical, I have bought a new set of speakers for another room in the home I will be able to try shortly, the Kanto YU4. So I'll see how I get on with these! Not expecting any difference mind you, but you never know.


----------



## davehutch

Audioboxer said:


> While I've had no luck with USB and have now just stuck with optical, I have bought a new set of speakers for another room in the home I will be able to try shortly, the Kanto YU4. So I'll see how I get on with these! Not expecting any difference mind you, but you never know.


Hope you get to the bottom of it


----------



## Audioboxer (May 19, 2021)

davehutch said:


> Hope you get to the bottom of it



Thanks, but no such luck. Same issue with these Kanto YU4 speakers (the audible pop out of one speaker).

I asked Fostex for some more help but no one has responded from customer service yet. I guess I might just be sticking to optical only from PC lol.

If it's not a faulty unit I have, and I don't think it is that, the only thing I have left to test is one of those decent quality USB isolators (the £50 ones that can do full speed USB, not the slower ones around £15). Be surprised if that works though given I've tried powered USB hubs and a laptop running on battery.

Only thing I haven't managed to try out is another operating system than Windows 10.


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## Audioboxer (May 19, 2021)

Here is a conundrum to throw the cat in amongst the pigeons. The Kanto YU4 which I still have on my desktop as I'm quite enjoying them here for now started to display loud audio buzzing/humming when I booted up a game and my 2080Ti kicks in (high power draw card). This is with optical out from my PC, phono out from the Fostex.

In order to clean this up I tried running optical out from the Fostex to the Kanto YU4 as unlike my other powered speakers this has an optical in. Clean as a whistle, even with a game running and my 2080Ti buzzing away lol (I have a watercooled setup so next to no fan noise lets me hear the coil whine off my 2080Ti).

Is it possible to run optical in to a DAC but still end up with interference over the phono out if there is a grounding issue/something nearby causing interference? I was running phono out to my other speakers over optical and had no issues, but maybe these Kanto speakers are a bit more sensitive.

The interesting thing about this buzzing from the speakers is it stops if the game is quit. Suggesting it's my 2080Ti causing it when the PC is drawing a lot of power. Even more interesting is I can pull the optical cable from the Fostex and the buzzing remains! It goes away when the game is quit. This has me thinking is this because of my wall power adapter the PC and Fostex are plugged into???

Heading under the desk to do some plug management/testing.

*edit:* LOL, this was a grounding issue with the speakers alone because they were plugged into the same outlet as my monitor. Once my monitor was outputting at 144FPS (drawing more power), it got the speakers buzzing 😂😂😂 This is why using optical in on the back of them had no noise. That doesn't solve the Fostex speaker pops over USB, but it shows not to plug speakers into this outlet (these speakers are just normal kettle plug).

*edit2:* OK, Kanto Speakers plugged into another outlet in this room (it's own plug, not an extension or the same plug as PC is hooked up to), still get buzz when my monitor is running at 144Hz/FPS. This is with NO audio playing at all (USB/optical input disconnected from Fostex, only phono out cables connected between speakers and Fostex). If I turn my monitor off the buzz pretty much stops or goes super faint. I'm no electrician but this suggests to me this whole room  the outlets are in will be on the same loop causing interference as and when my PC draws a lot of power (2080Ti running/monitor at 144hz). Going to take the Fostex out of here and experiment with my laptop and these Kanto speakers in another room. Out of the 3 powered pairs I have they are the only ones reacting like this when my monitor is on.

*edit3:* Bingo, isolated both the Fostex and Kanto speakers on their own outlets in this same room and that gets rid of the humming and buzzing when a game is loaded up. Just back to the issue I've always had, the loud pop noise out of one speaker when audio is stopped for a second and starts up again (easiest way to reproduce is the youtube slide).


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## davehutch

Audioboxer said:


> Here is a conundrum to throw the cat in amongst the pigeons. The Kanto YU4 which I still have on my desktop as I'm quite enjoying them here for now started to display loud audio buzzing/humming when I booted up a game and my 2080Ti kicks in (high power draw card). This is with optical out from my PC, phono out from the Fostex.
> 
> In order to clean this up I tried running optical out from the Fostex to the Kanto YU4 as unlike my other powered speakers this has an optical in. Clean as a whistle, even with a game running and my 2080Ti buzzing away lol (I have a watercooled setup so next to no fan noise lets me hear the coil whine off my 2080Ti).
> 
> ...


Have you done the usual check for the fridge switching on and off on the same circuit? Anything with a thermostat basically


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## Audioboxer (May 19, 2021)

davehutch said:


> Have you done the usual check for the fridge switching on and off on the same circuit? Anything with a thermostat basically



I just added in a quick third edit above, I totally got rid of the interference from my monitor/GPU by isolating the Fostex and Kanto speakers away from the outlet the PC uses whilst still having both USB and optical cable running to my PC for input. Leaves me back at square 1 though, I still have that same loud pop noise when a USB input goes to my Fostex and I do something like seek through a YouTube video.

I can't answer for why its only the Kanto speakers that are having this hum off the monitor/GPU, but who cares, fixed it lol.

To put all of this to bed I think I'm just going to be happy with optical in from my PC and I'll stick with phono out and have the Fostex/whatever powered speakers I leave in here isolated. I've got a few outlets I can quite easily work with.

I only bought this DAC because of a friend constantly saying I should use a DAC for headphones rather than put up with motherboard audio. They were right, my headphone use has been amazing since. But I also bought this dac because it _could_ do PC speakers, and that has caused all the headaches lol. Something I wasn't even primarily buying them for!


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## Audioboxer (May 19, 2021)

Okay here is something else to chew on, USB from my PC to Fostex but optical out from the Fostex to Kanto YU4. I think the optical out on the Fostex is some sort of passthrough though as volume knob on the Fostex doesn't really work right when using optical out. No speaker popping when seeking videos on YouTube.

Using optical out means if you switch to headphones on the Fostex you get audio on the headphones and audio still plays out of the speakers lol. My other two pairs of powered speakers don't have optical in so I couldn't test this configuration till now.

Tempted to buy this and use it between the phono out on the Fostex and the phono in on the speakers https://www.amazon.co.uk/Behringer-...000KUD2G4/ref=cm_cr_arp_d_product_top?ie=UTF8 See if it gets rid of the pop.


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## Audioboxer (May 21, 2021)

Woohoo, finally fixed my issue. The Behringer MICROHD Hum Destroyer HD400 worked. The most important thing is the piercing pop noise is away when skipping youtube videos and so on. This is with USB input and RCA output. No more need for optical.

But as a second added benefit I can even have the speakers/Fostex on the same power outlet as my PC/Monitor and there is no humming or buzzing.

Apart from the HD400 just had to pickup 2 packs of these https://www.amazon.co.uk/gp/product/B07ZNHQ8LX/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 With all the audio cables I have lying around surprisingly I had none of these lol.

Another question for the knowledgeable, one of my friends said the speaker popping could also be clipping? As in because these are powered speakers and have an amp in them they were turned up too high and the Fostex too low. DAC overdriving the amplifier if not configured properly? I do have to say even without the HD400 if I lowered the speaker volume but increased the Fostex volume knob the popping was reduced. I guess this is where a separate DAC/AMP combo would have suited me seeing as I'm trying to run speakers and headphones.

Everything is crystal clear just now though so I'm not touching anything, I'm not buying anything else and I'm happy


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## davehutch

Audioboxer said:


> Woohoo, finally fixed my issue. The Behringer MICROHD Hum Destroyer HD400 worked. The most important thing is the piercing pop noise is away when skipping youtube videos and so on. This is with USB input and RCA output. No more need for optical.
> 
> But as a second added benefit I can even have the speakers/Fostex on the same power outlet as my PC/Monitor and there is no humming or buzzing.
> 
> ...


Excellent news. Well done for getting to the bottom of it 👏🏻


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## Audioboxer (May 21, 2021)

davehutch said:


> Excellent news. Well done for getting to the bottom of it 👏🏻



lol, I'll be damned if I know what exactly my multitude of issues were, but between a powered USB hub, grounded power supply for the Fostex and a Hum Destroyer HD400 I've got a working setup on this PC between speakers/headphones with all my powered speakers. So the YU4s can go elsewhere now where they can take advantage of bluetooth.

I've learned a bit along the way even if I'm still a total noob to understanding digital and analog audio. I think in regards to the Fostex I've learned it's a top headphone amp (in its price range), but speakers YMMV depending on what you're hooking up. Might be better with a separate DAC/amp if you're wanting to service speakers and headphones.

As I said way back I'm primarily using headphones at the PC but when something isn't working right I get a bit obsessed to find out why and now I've got some decent speaker output at the PC for when the headphones are off 

*edit* - For what it's worth other people seem to be having the popping issue I described with Windows 10 with a range of DACs, motherboards and soundcards https://www.techpowerup.com/forums/...-or-clicking-windows-sound-icon.265858/page-2 So who knows if the current builds of Windows 10 are also introducing issues for some if they have other issues that contribute to it (badly wired electrics/etc). One of these days I'll give Linux a punt off USB or something to test what sound defects I can reproduce.


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## tinkererGCH

I just got the Fostex HP-A4BL (initially they send me the HP-A4, which I was able to use with USB and Toslink on Arch based Linux). Now I have the Burson Audio Conductor 160D and that works out of the box with the USB. 
The Problem with both Fostex is, when plugged in (BL giving power and powered USB) the 44.1 LED is red flashing. Both have the lastest Firmware V1.1. Annoyingly with Windows 11 they work, but I hate Windows. Both Fostex are being detected by Linux and I can choose between USB and Optical (currently not usable for me). When I do the audio test (left, right speaker) those are being done but no sound.
I am using pulseaudio and alsa. in Alsamixer it shows for the Fostex ("This sound cevice does not have any controls"). but that would mean it cannot being controlled, the buttons and volume itself are physically there and can work with. Also that means no playback, because the 44.1 LED is flashing  red. DMESG shows also the devices when plugged in.

Any ideas on what to check is appreciated. I will get next analog RCA converter to optical and will see if that works.


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## Deleeh

I believe that the Hb 4 does not need a driver and is powered by USB.
The Hp 4 BL comes with a power supply and needs a driver, I think, but the Hb 4 does not.
The question is whether it is Linux capable at all.

The Hp 3,4,4BL devices are relatively old.
I think from 2012, the technology in headphone amplifiers was not as far as today's and also not fully friendly to different operating systems.

Have a look at the manual.
If necessary, contact Fostex customer support, even if they are sometimes strange.

I had the Hp 3 A and it worked without problems and was the best of the 3 headphone amplifiers.

I also had both units from the 4 series and they sounded strange and I also had problems with one unit under Windows although it was compatible.

Does Linux actually recognise the Hp4 Bl or not?
Sometimes you have to be able to select the device somewhere in the system that it should do the sound output, maybe that helps under the audio settings.


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## tinkererGCH

Fostex HP-4A worked with USB and optical before getting the Burson Audio Conductor. now Fostex HP-4A( and BL) are being deteced by Linux correctly as USB (currently do not have othe ptical option). Now the moment they have power the 44.1Khz LED is flashing and keeps flashing, even when detected by Linux and selecting the USB Audio. But noaudio is coming out. In Windows 11 they work out of the box unfortunately


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## tinkererGCH

I solved the issues for both Fostex HP-A4 units. I was looking into using pipewire and replacing pulseaudio. Found some good videos ArcoLinux : 2515 How to switch from pulseaudio to pipewire and back - sound server .
running inxi -F I saw that Sound API: ALSA, Sound Server: pulseaudio AND also pipewire were running. So I uninstall everything related to pulseaudio, did a reboot and VIOLA both Fostex HP-A4 are now working with USB.


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