[dayh8]

Quote:

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.
 
 

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.
 

 

[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?

 

[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.
 
 

 

[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?

 

[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?

 

[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

 

[dachness]

Quote:

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!   

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... 
 

 

[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?

 

[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)?

 

[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...

 

[zoologico]

Anybody?

 

[zoologico]

C'mon

 

[miko16]

Anyone tried replacing a better battery for this amp?

 

[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.