# Audinst AMP-HP: impressions and reviews



## 12345142

You might know Audinst for their HUD-MX1, a good-sounding and affordable DAC/amp. Well, they've recently announced the AMP-HP, a portable headphone amp. It's going to be released on June 17.
  http://audinst.com/en/bbs/board.php?bo_table=AMPhp&wr_id=5


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## project86

Looks good. I think I'll pick one up if the price is not crazy (I doubt it will be considering the mx1 was very reasonably priced). I was just thinking I needed another good portable amp for a separate little setup I've been planning, so this should fit perfectly.


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## Austin Morrow

I will be getting one very soon and will have a review up after testing it out a little while.


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## 12345142

...and it's released. Just search 'audinst' on eBay:
  http://shop.ebay.com/i.html?_from=R40&_trksid=p5197.m570.l1313&_nkw=audinst&_sacat=See-All-Categories
  The price is fairly reasonable, although closer to the MX1's price than I expected. Perhaps I should buy one.


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## TheWuss

i would think the barrel detail on the aluminum body would make it difficult to stack it together with another device.
  just sayin'...


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## 12345142

It is flat on one side, though, so it should be fine for a two-unit portable setup.


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## Austin Morrow

I really hope so, I love my STUDIO-V as an amp and a source, but I want a little more juice.


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## project86

I just noticed it comes with a mini-mini cable as well as an iPod LOD cable. Very thoughtful of them! I'm sure they are not super duper high end fancy cables, but it still seems like a very comprehensive package.


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## 12345142

Looks like Mike from Headfonia's going to get his hands on an AMP-HP. As an MX1 owner, my expectations are as good as his.


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## project86

Quote: 





12345142 said:


> Looks like Mike from Headfonia's going to get his hands on an AMP-HP. As an MX1 owner, my expectations are as good as his.


 

  
  I agree. The mx1 sort of set the standard in that price class and still holds up very well. So I expect good things from their new amp. I know they have been working on it, or at least in the planning stages, ever since the mx1 first came out.


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## AlexRoma

﻿
  Quote: 





> I agree. The mx1 sort of set the standard in that price class and still holds up very well.


 
   
  Indeed ! I couldn't have said better


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## project86

Mine is on the way. Couldn't resist.


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## project86

Guess what arrived in the mail yesterday? The folks at Audinst ship very quickly.
   

   
   

   
  It's very nicely built and very small, being just a tiny bit larger than my TCG T-Box (which is very small!). Package is well done just like the HUD-mx1 was. I love the layout with the input in the rear and the headphone jack on front - it makes things cleaner in my opinion. 
   
  The sound? Seems quite good but it is way to early to judge. I guess the only meaningful comment I could make this early is that it isn't an utter disappointment or anything of that sort. That would be obvious even with the limited listening time I've had. But I'll be spending time with it over the next few weeks to really figure it out.


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## Austin Morrow

Quote: 





project86 said:


> Guess what arrived in the mail yesterday? The folks at Audinst ship very quickly.
> 
> 
> 
> ...


 

 You lucky b.......


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## Austin Morrow

Take a picture of it hooked up with your source!


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## project86

Quote: 





austin morrow said:


> Take a picture of it hooked up with your source!


 


  For a sense of scale?
   
  I will when I get a chance. Didn't think to do that at the time.


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## Austin Morrow

Quote: 





project86 said:


> For a sense of scale?
> 
> I will when I get a chance. Didn't think to do that at the time.


 
  Yes, that and I just love pictures.


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## project86

Quote: 





austin morrow said:


> Yes, that and I just love pictures.


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## Austin Morrow

Wow, that thing is tiny!


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## 12345142

Wow, it looks like it's almost as small as the Shadow. If it sounds good and delivers decent power, I'm sold.


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## Austin Morrow

I've got one coming soon. I'll do a comparison to the TTVJ Slim and hopefully the HeadStage Arrow


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## Anaxilus

Sorry but that hump is a horrible design.  They got some AA battery crammed in there?  Should be interesting to hear how it compares to the Arrow using the same opamps.


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## Austin Morrow

I was accepted as a reviewer, yayhoo!


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## Austin Morrow

Quote: 





anaxilus said:


> Sorry but that hump is a horrible design.  They got some AA battery crammed in there?  Should be interesting to hear how it compares to the Arrow using the same opamps.


 


  I have an Arrow coming soon, so I'll have a comparison hopefully


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## project86

Quote: 





anaxilus said:


> Sorry but that hump is a horrible design.  They got some AA battery crammed in there?  Should be interesting to hear how it compares to the Arrow using the same opamps.


 


  I've gone back and forth on it. When I first saw the pictures I thought it looked kind of unique and attractive from a visual standpoint. Then I started considering ergonomics and thought it might be annoying. When I actually received the amp I was surprised by how small it is, so I figured the bump wouldn't matter. But then I started using the amp and it does get in the way just a little.
   
  The flat side is obviously going to have your source against it. So the bump side is always going to protrude. I'll open the case when I get a chance so I can see what is going on inside that requires the bump.


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## Austin Morrow

Hmm, it says it has a 300 ohm output. Has anyone tried the Audinst Desktop amp? That's 600 ohms of power, I wonder what it can drive...


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## project86

Quote: 





austin morrow said:


> Hmm, it says it has a 300 ohm output. Has anyone tried the Audinst Desktop amp? That's 600 ohms of power, I wonder what it can drive...


 


  I'm not sure you are using the terminology correctly. AMP-HP is listed as being able to drive 32 ohm through 300 ohm headphones. HUD-mx1 also included 600 ohm headphones. AMP-HP has an output impedance of 5 ohms.
   
  The only actual power rating they list is 300mW per channel into a 32 ohm load.


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## Austin Morrow

Quote: 





project86 said:


> I'm not sure you are using the terminology correctly. AMP-HP is listed as being able to drive 32 ohm through 300 ohm headphones. HUD-mx1 also included 600 ohm headphones. AMP-HP has an output impedance of 5 ohms.
> 
> The only actual power rating they list is 300mW per channel into a 32 ohm load.


 


  Yeah, I screwed up, I'm just now learning all of this terminology.


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## Austin Morrow

Look what arrived! I'll open is soon, not yet though


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## project86

Cool! Let us know what you think. I haven't had a ton of time to spend with mine yet, mostly burning it in. My very rough, very initial impressions are that it is fairly neutral and transparent and sounds quite nice.... but it will take a lot of listening to really figure it out.
   
  I did pop the case yesterday to see the interior. It looks well laid out in my amateur opinion. It also seems that the "hump" in the case is mostly functional, and necessary:
   

   

   
  There are some capacitors there on on end and the Alps pot on the other side. If there was no hump, they would not fit at all. The hump could be a little smaller, or more flat on top, but it wouldn't make it much more pocket friendly. Also I suspect they wanted a certain amount of clearance above the caps. So the controversial hump is there for a reason. 
   

   
  This is how I'll mostly be using the AMP-HP: QLS QA-350 player, line out to the Audinst, powering the 1964-T customs.


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## project86

By the way, are we using this as the "official" AMP-HP thread? Or should someone start a new one? I don't care either way.


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## Austin Morrow

I'll just use this as the AMP-HP thread. Someone should change the name to something like "Audinst AMP-HP: Impressions & Reviews"


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## Austin Morrow

Going to use my TTVJ Slim for a week still, I'll let this burn in for a few days while I am gone.


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## hello im sean

looking forward to these comparisons, any comment on sound stage?


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## munkyballz

Looking forward to hearing some impressions.  Their MX-1 seemed to be universally well received, hopefully this sucker sounds good too.  Though not a huge fan of the "hump" design.


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## 12345142

Quote: 





austin morrow said:


> I'll just use this as the AMP-HP thread. Someone should change the name to something like "Audinst AMP-HP: Impressions & Reviews"


 

 Gladly.


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## Austin Morrow

Back home! Tested my TTVJ for a few days. Will be uploading some pics of the AMP-HP in about 30 mins. Stay tuned!


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## Austin Morrow

New pics!


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## imackler

But how did it sound?! The suspense...


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## Austin Morrow

Quote: 





imackler said:


> But how did it sound?! The suspense...


 


  Haven't tried it yet, still testing out my TTVJ Slim.


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## Austin Morrow

Alright, here is the thing, I go to insert any headphone jack and it makes a loud banging noise and takes a fair amount strength to insert, same with taking it out. I'm going to email Audinst to see if that's defective.


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## project86

Quote: 





austin morrow said:


> Alright, here is the thing, I go to insert any headphone jack and it makes a loud banging noise and takes a fair amount strength to insert, same with taking it out. I'm going to email Audinst to see if that's defective.


 


  The jacks on mine are a little snug as well, with the "input" being a more tight than the headphone. Some things I plug in do fine but others require some effort. I've had that happen before and it usually loosens up a little over time.


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## Austin Morrow

Quote: 





project86 said:


> The jacks on mine are a little snug as well, with the "input" being a more tight than the headphone. Some things I plug in do fine but others require some effort. I've had that happen before and it usually loosens up a little over time.


 

 Alright, they said it's not defective and it should loosen up.


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## Audiophile1811

Can't wait for the reviews. I love my MX1 and I need to know what the AMP-HP sounds like!!!!!


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## project86

I apologise for posting all the tantalizing pictures but not saying anything about the sound... I've just been so busy with other stuff lately. But I finally used the AMP-HP for a few days, paired with a QLS QA350 player and powering the Unique Melody Merlin. So far it seems to have a similar personality as its HUD-mx1 sibling: fairly transparent and neutral, no major colorations or flavors added to the sound, and quite good for the price. The main thing that stuck out to me so far has been the clarity. It is very detailed, without being overly analytical or thin. 
   
  I hesitate to state any strong conclusion after so little use.... but if it continues to perform this way with various headphones, then this is going to be one of the strongest options around in the sub $200 category.  More to come as I get more time with it.


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## 12345142

Okay, so I got to listen to the AMP-HP a bit at a headphone store today, and it's definitely quite good for the price. The bulge protrudes a bit more than it seemed in the photos, but I personally don't mind. It was able to drive 32 ohm DT880s and DT990s quite convincingly, being fed the line-out from my HiFiMan HM-601. The sound is slightly warmer than neutral, and the bass punch is nice - much like the MX1, but slightly more refined to me, possibly because of the superior source. I also like how the power turns on/off automatically when the headphone is plugged/unplugged. Seems like a winner to me.


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## 12345142

Um...hello? Is anyone there?


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## project86

I'm here!
   
  I'm just finishing up my review on this amp. Hope to post it within the week. It's a very impressive little amp and I'm surprised there is not more discussion about it..... considering the HUD-mx1 has become very popular, I thought people would jump on the next release from the company.


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## shoegazebass

Gah! I need to know more about this amp - it seems perfect to use with my 1964-Qs! Can't wait for any and all reviews about this little amp;


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## project86

Review finally finished and posted:
   
http://www.head-fi.org/t/568054/review-audinst-amp-hp-portable-headphone-amplifier#post_7697280
   
  Mike over at Headfonia mentioned that he is working on a review also. He makes it sound like it is the next thing he will post, so it should be fairly soon. I have no idea what he thinks of it, so I'm curious as well. I really enjoy it myself.


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## 12345142

Great review as always, project86. Now I want one too - partly for brand loyalty, partly for my HD25s. Haven't heard from Austin Morrow in a while...


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## project86

I think he mentioned reviewing some other amp first, and then the Audinst.


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## WestLander

Thought I would translate and summarize some of the reviews the amp has been getting in Japan.
   
  First from kakaku.com (Japanese deal/price aggregator). The AMP-HP gets an overall 4/5 stars:
   
  ====
   
*マ・マ *writes that he's not sure who the amp is tailored towards, or who he could recommend it to. For those who are used to, and like, rolling opamps he would recommend buying the iBasso D2+ at the same pricepoint. The slight bump on the amp comes in for some criticism, but he/she admits that after 3 days one quickly gets used to it. The battery also could be better in their opinion, perhaps deploying the 006P rather than the stock battery - a change which improves the sound quality in their opinion. 
   
  So for those who don't mind the hump, don't mind rolling opamps and don't have a large portable collection or want to build one, this amp may be for them. It is the cheapest rollable portable (in the Japanese market) and for not very much outlay the outputted sound can be changed quite dramatically. 
   
  The stock MUSES8820 is a little boring (in their opinion) and the resolution merely adequate
   
  MUSES02 lets the top end soar in comparison to the 8820, and tightens up the sound, but at the loss of some emotionality in the sound.
   
  LME49860 is their top recommendation. Separation is good, and the sound becomes clear-cut/ 3 dimensional. Overall, clarity and detail are improved, without any feeling/impression of "edginess"
   
  LME49720 is grainier than the 49860 and not worth buying over the 49860
   
  OPA2134 is very energetic and lively, but because of this it may not suit all kinds of music
   
  OPA2277 is more restrained than the 2134 but doesn't suit the AMP-HP very well
   
  So even with the drawbacks re:shape and battery and stock opamp he/she does like it very much. 
   
  ====
   
*Kenzo Konoike* was using the AMP-HP to power the Shure SRH440 (44 ohms) with the iPhone 4 headphone out as a source. Compared the sound through the amp to the iPhone jack the sound is clearly  better in quality, and the driving power of the amp shines through. The lower end of the Shure is extended (about an octave) but in a pleasingly composed and assured manner. 
   
  When running the SRH440 out of the iPhone, the lower end does bleed into the midrange especially on songs with a driving baseline, but the amp does a good job of improving the separation of the mids from the bass. He also notes that the amp may match better with phones of higher impedance as the gain is a bit much for the SRH440. 
   
  As for opamps, the MUSES8820 is quite good, but in comparison the MUSES02 is a little more mature, but lively in terms of sound (he writes the sound gives a feeling like water bubbling energetically out of a pipe). The lower end does extend down further and vocals in particular sound more harmonious/melodious. The soundstage widens out nicely, with improvements in positioning and location of instruments, and so the overall "live" quality of the sound gets better.
   
  ===
   
  Hope this has been helpful!


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## project86

WestLander - thanks for the post/translation! It is always nice to have a window into other opinions, especially ones that would otherwise not be accessible (to me).
   
  I'll have to pick up an LME49860 and give it a shot.


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## WestLander

Not a problem project86! I thought the info about opamp rolling would be useful to have posted here. I'd love to hear what you think of the LME49860 when you get the chance


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## dayh8

Quote: 





westlander said:


> *マ・マ *writes that he's not sure who the amp is tailored towards, or who he could recommend it to. For those who are used to, and like, rolling opamps he would recommend buying the iBasso D2+ at the same pricepoint. The slight bump on the amp comes in for some criticism, but he/she admits that after 3 days one quickly gets used to it. The battery also could be better in their opinion, perhaps deploying the 006P rather than the stock battery - a change which improves the sound quality in their opinion.
> 
> So for those who don't mind the hump, don't mind rolling opamps and don't have a large portable collection or want to build one, this amp may be for them. It is the cheapest rollable portable (in the Japanese market) and for not very much outlay the outputted sound can be changed quite dramatically.
> 
> ...


 
   
  Hi WestLander, et al,
   
  I am really, really new to all this, but I was intrigued by the suggestions at swapping parts out to improve the sound of the AMP-HP (mine should be here in a week or so) and I began researching some of the parts. Interestingly enough, the LME49860 appears to be available from Digi-Key for $4.34. It appears from the pictures posted by Project86 that this would be a simple plug-and-play operation. Is this the case?
   
  My real question, though, is that the only battery options I find listed with a part number 006P is a standard 9v rectangular battery. If there another form of 006P that I am not seeing, and if not, are they simply suggesting removing the rechargeable battery and replacing it with a 9v?
   
  I hope these questions aren't completely ignorant, but I won't learn unless I ask. Thanks for any input!


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## WestLander

Quote: 





dayh8 said:


> My real question, though, is that the only battery options I find listed with a part number 006P is a standard 9v rectangular battery. If there another form of 006P that I am not seeing, and if not, are they simply suggesting removing the rechargeable battery and replacing it with a 9v?


 

 I took another look at the 006P battery swap mentioned in the review, and it seems like he or she is saying that if Audinst could have adjusted the design of  the amp, (and in doing so, remove that hump), they could have fitted a higher capacity battery which would improve sound quality. The form factor is different from the stock battery so I'm not sure if it would fit in the current case. There do appear to be rechargeable versions of the 006P, available as the PP3.


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## dachness

Subscribed, would love to hear more listening impressions and if LME49860 provides any benefits.
   
  Daniel


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## dayh8

I've had my AMP-HP for only a day now, so these are only initial impressions without any real burn-in time. I've run the amp out of my MacBook Pro and my T-Mo G2x (LG P999) phone. Haven't put it on my iPad or iPod yet. My reference headset is my trusty Senn HD280's. I know a lot of people don't like these cans for one reason or another, but I have had my pair for probably 7 or 8 years, and have no issues with build, comfort, or sound. I have also tried them out with a brand new pair of ATH-M50s (no burn in on them yet either).
   
  Overall I think the amp does exactly what I wanted - it cleans up the highs a bit and has no huge impact on the overall sound. It does not push the highs, or make them unbalanced. It simply seems to make them sharper and thus increase the detail available. (It even manages to do this on a set of Phiaton MS 400 cans that I am pretty excited to send back as a failed experiment in allowing my eyes to buy something that are meant for my ears... but I'll say more about that in the proper place.) In other words, I think that the sound output is very neutral, but does bring out the detail in the highest-mids to the highs, while not being detrimental to the lows in at way. For me, this is pretty much perfect. 
   
  I think that the AMP-HP will serve its purpose well for days that I want to run my M50's a little cleaner, and will probably find its way into my bag for most flights, and will be a stock part of my very new and small desktop audio gear collection. It will also be a great platform for whatever my next can upgrade is, even if that is a long way off in the future.
   
  @dachness: After I get everything burned in and get more used to the sound on the AMP-HP, I'll order an LME49860 and see if I can tell any difference. I am not sure that my ears are trained enough to tell a real difference, but we shall see.


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## dachness

Quote: 





dayh8 said:


> @dachness: After I get everything burned in and get more used to the sound on the AMP-HP, I'll order an LME49860 and see if I can tell any difference. I am not sure that my ears are trained enough to tell a real difference, but we shall see.


 

 Thanks 
	

	
	
		
		

		
			





. Very interested to see how they are with ATH-M50. Looking for an amp for iPhone4 and ATH-M50. Sounds great with iPhone4 currently but as usual I wouldn't mind increase SQ. If you have a chance to compare iPod/iPhone headphone out vs the amp and a LOD it would be appreciated.


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## dayh8

Quote: 





dachness said:


> Thanks
> 
> 
> 
> ...


 

 Hey Dachness,
   
  I think that if you feel the M50 needs an amp, the Audinst is going to be a great combo. I have been listening w/ and w/o the amp for a few days, and while I *think* there is a slight boost in SQ, I am not sure if I am able to fully appreciate it. That being said, whether it is a placebo effect or real, I do think that the mids and highs are just a bit sharper on the M50s when run through the AMP-HP. I am really loving my M50s, and though I'm still burning in both the cans and the amp, I think that they make a really nice combo. I think the sound is detailed and rich, with a nice soundstage in all directions. The bass is rich and clean, and the overall presentation is very balanced and natural. I have read a couple of people who poo-poo the M50, and I am pretty sure I will not be taking their advice on headphones, because this is a sound signature I love - and coupling with the Audinst seems like a pretty perfect match! If you like your M50s alone, and want to go with an amp, I don't think you will be disappointed by the AMP-HP.


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## nivrethejugg

I thought I could live with the form factor of it. I was wrong.
   
  Having previously owned a cmoy, I took a penguin amp tin and punched holes according to the board. In all honesty, I think I prefer how the original casing looks compared to the penguin tin but the hump really is something I cannot get used to. Putting them in a penguin tin also allows me to opamp roll more easily. 
   
  Pictures:
   

   
  That said I like the amp. Sound signature and all. I would say it is a tad bit too neutral though.
   
  Thoughts?


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## dachness

You should send Audinst a link to this thread. I think they will be surprised that some may prefer an altoids tin to their case due to it being flat. Its too late for them to do anything for this amp but they can take notes for future products.


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## project86

Wow, that looks quite good - much better than I would have expected if I just tried to picture it without seeing the actual result. 
   
  I do think the amp is fairly neutral, which is a good thing for the most part. What is it that you would like more of?


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## nivrethejugg

dachness: I agree. I will spend extra if they were to make a new casing for the AMP-HP. With the extra space, who knows what wonders they can make? The worst this can get is more options for batteries and a bigger case. 
   
  project86: I feel like they lack a certain element that can make people relate to their sound signature. When it comes to Audinst's, all I think about is the emphasis on the low bass and the clean highs. Of course the AMP-HP is more than just that but if I had 5 seconds to describe the amp, that would be it. 
   
  Anyway, I would want a wider sound stage. I don't really hear much of an improvement on the depth though, strange. Both Mike and your review seem to say otherwise. Though it might be because I have yet to burn them in completely.
   
  Any of you tried any other opamp that improves the amp?


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## dayh8

Hi All,
   
  I've decided I'm going to be selling my AMP-HP. Something has come up that I need to put the money towards. I bought in on eBay from Audinst two less than two weeks ago. It's had about 15 hours of play time, and three charge cycles including the first out of the box. I paid $159. I can ship it out for free for $150 with a tracking number and insurance via FedEx. Figured I'd throw it on this thread before I listed it on the main listing page. PM me if you are interested.
   
  Cheers


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## dachness

Quote: 





westlander said:


> *マ・マ *writes that he's not sure who the amp is tailored towards, or who he could recommend it to. For those who are used to, and like, rolling opamps he would recommend buying the iBasso D2+ at the same pricepoint. The slight bump on the amp comes in for some criticism, but he/she admits that after 3 days one quickly gets used to it. The battery also could be better in their opinion, perhaps deploying the 006P rather than the stock battery - a change which improves the sound quality in their opinion.
> 
> So for those who don't mind the hump, don't mind rolling opamps and don't have a large portable collection or want to build one, this amp may be for them. It is the cheapest rollable portable (in the Japanese market) and for not very much outlay the outputted sound can be changed quite dramatically.
> 
> ...


 

 Found an article on op amps that mentions the LME49860, thought I would pass it along in case you haven't read it.
   
  If you are considering changing the op amp you may want to consider the NE5532 along with the LME49860. This Op Amp Measurement article has talks about both. Based on that article it looks like the LME49860 is a good op amp, however the NE5532 can keep up for the most part while being significantly cheaper. 
   
  EDIT: Update, I was doing some digging on the MX1 and I believe it has the LME49860 as the stock op amp. So any one with the MX1 could try switching the op amps between the two...


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## clairyvic

So this thing would be able to drive a 50olm amp with only 92 db sensitivity, that requires at least 100 mW per channel to drive effectively and make them real loud? Howabout the hiss, is it noticable?


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## clairyvic

And why are there so few reviews for this amp if the specs are so good? In fact a google search reveals very little. For people who have tried it is it really as powerful as it says it is (300 mW per channel at 32 olms for a grand total of 600 mW at 32 olms)?


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## zoologico

Please any comparation with fiio e12?
The HP is now abaible for 90$ on ebay, a great deal. 
We need any audinst hp vs anything...


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## zoologico

Anybody?


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## zoologico

C'mon


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## miko16

Anyone tried replacing a better battery for this amp?


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## dwayniac

I have the AMP-HP as my home amp paired with a HIFIMEDIY Tiny DAC. I put an LM4556 opamp in it and I don't foresee changing it any time soon because it sounds good with my SR325i.


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