Review: Portable amp roundup! 37 portable amps reviewed and compared

[wolfen68]

Originally Posted by HeadphoneAddict

mrarroyo is sending Skylab one to add to the review.

Hmmm.....mrarroyo has an SR71 and sold his SR71a as far as I know....so I assume it's actually an SR71 coming Skylab's way?

[HeadphoneAddict]

Originally Posted by wolfen68

Hmmm.....mrarroyo has an SR71 and sold his SR71a as far as I know....so I assume it's actually an SR71 coming Skylab's way?

Maybe it was Jamato8, I am confused. Sorry.

[mrarroyo]

Yes I sold my SR71A, but the SR71 is going to Rob. BTW, IMO the SR71 sounds more open, extended, clean, and with more detail than the SR71A.

[Skylab]

Wait - I have already reviewed the SR71 - it's in the rankings - I don't need to do it over again

So for now I guess I am NOT reviewing the SR71A.

[Skylab]

Originally Posted by peta10dye

Hi Skylab,

First, must say I fully agree with everything said about and am loving the pretty spectacular P-51 Second, was just wondering, being a bit of a basshead myself (I know, sorry ), which of your top rated amps would tend to favour bassheads (Slight, lol), if not actually the P-51. Interested to know which of your top few have the most/biggest bass punch, though loving what the P-51 is doing.

As long as we are talking about amps that do not use a bass boost, then the answer is the P-51 is as good a bass amp as there is, although lots are good.

[Skylab]

Update 1/4/09

HeadphoneAddict was nice enough to loan me the 3 following amps for review. While all three incorporate USB DACs, and I did very briefly listen to their USB DACs, the comments below refer to them being used ONLY as headphone amps, driven by my iMod iPod from their analog inputs. HeadphoneAddict has done the definitive review of these products as DAC/AMPs, and my review has only ever been about them as portable amps.

> iBasso D3 Python

iBasso

The D3 Python is nice looking, well built, and medium-large portable headphone amp. It does not have a facility for charging batteries (that I could tell). Does have a USB DAC, and gain switch.

Build Quality: A: Very attractive and sturdy chassis. Much nicer than previous generation iBasso products.
Treble: A-: The treble is reasonably clean, transparent, and neutral. The treble is just a little soft, and lacks ultimate air and extension. I don’t think the treble is a problem, though, unless you try to use it with dark or rolled off sounding headphones. This was evident in comparison to the very extended but smooth treble of the Qables iQube.
Midrange: A: Nicely open, transparent, and clean sounding. The mids were smooth and enjoyable, if just slightly warm (which is better than the alternative). Nothing truly special, but nonetheless excellent performance.
Bass: A-: Full, punchy, and well defined. Enjoyable bass on music like Steely Dan’s “Babylon Sisters”. Could have a little better depth. But it was very enjoyable nonetheless.
Neutrality: A: The most neutral sounding iBasso ever IMO. In fact, I was surprised to find it more neutral than several other amps I have heard, which went through the review process recently. Would be A+ if it were not for the very slight treble reticence and added midrange warmth. For me, a better amp for Beyers or Grados than for Sennheisers.
Soundstaging: A: Great depth and width, and a very palpable image. Excellent performance here. Nice wide presentation of Alison Krauss and Union Station’s live recordings.
Transparency: A-: Occasionally just a bit thick sounding, but generally very transparent.

The D3 Python is the best iBasso yet by far. It’s a great performer, and at its price, and with the nice built in DAC, it’s a great product. I still felt it wasn’t quite as detailed as the Meier 2Move, and another head-fier who did some comparative listening with me agreed, but that doesn’t take away from how good the iBasso is. The Meier is a little more neutral. If you want a great amp/DAC combo and want your sound just a little warm/mellow, the D3 Python is an excellent choice.

> iBasso D2 Boa

iBasso

With regard to the D2 Boa – In general, it has a sonic signature close to the D3 Python, but seems to have an overall lower level of performance. It was a little less clean, a little less transparent, with a less well defined soundstage, less treble detail, and less bass definition. It has the same basic sonic signature but the mids are a little more colored, and has an even more noticeable lack of treble extension. You can basically take my rankings for the D3 and just take them all down a half-grade.

It is a good value for the money at its price of $165, But for those wanting just a headphone amp in this price range, the Meier XXS is a much better choice. If you DO want an amp/DAC combo, I would save up for the D3 Python. It’s noticeably better and not that much more.

If you look at the rankings below, you will see I think the D2 fares well. But against competition from its own D3 brother, it does not quite measure up. The D2 Boa is a nice product , and its owners will be quite pleased with it. I can recommend it enthusiastically only to people who have a strict budget and need a amp/DAC combo.

> NuForce Icon Mobile

Nuforce, Inc

The NuForce Icon is incredibly light, and fairly small. It’s also very cheaply built. It has no actual power switch, but comes on when you plug in headphones – which I don’t like. It has a gain switch, which is hard to operate.

Build Quality: B-: See above. It was also fussy in terms of its headphone jacks. I know it’s wrong to expect much build quality from a $99 amp/DAC, but you sure don’t get it.
Treble: B: Piercing, bright, aggressive, and somewhat unclean treble compared to any of the better amps here. Not truly dreadful in absolute terms, but the amps main liability. Unless you have VERY dark, rolled off headphones, BE CAREFUL. The NuForce’s treble is kind of scary. Downright unpleasant with my Beyer headphones. Better with the AT ESW9’s, but they are pretty forgiving.
Midrange: B+: Slightly forward, and with a noticeable chalky grain. Decent, but not great. Vocals have some extra presence which is can be nice, but is not real.
Bass: A-: The bass was very good. Both powerful and deep. Not world class, but not as problematic as the above
Neutrality: B: Generally not very neutral. Forward and bright sounding. VERY careful headphone matching will be needed, and with something like the Ultrasone 780, it will be just plain awful.
Soundstaging: A-: Convincing image stability, and reasonable width combined with excellent depth give it a good score here.
Transparency: B+: At times it seemed very transparent, and with other material, it was not at all. The aggressive, forward sound signature just didn’t give the illusion of transparency.

I guess the best thing I can say about the NuForce is it’s cheap. But I didn’t really care for its sound. My recommendation is to save your money for something better.

Conclusions (1/4/08)

NOTE: All new reviews have to be added to the end of the thread due to the length of this post - only the rankings will now change.

OK, so now it’s now 47 amps! Here is my view on how the amps stacked up. Note that the sum of the "Grades" I give does not always tell the whole story in how I rank them, since the whole is sometimes greater or lesser than the sum of the parts, and I am often forced to split hairs here, since the list has gotten so long. Also please note that even if these amps include a DAC, that DAC performance was NOT a factor in these rankings AT ALL. Also, for clarification, this ranking is based on sound quality ONLY, and does not take things like size or battery life into account.

1. Triad Audio Lisa III @ $925.00
2. Qables iQube @ $605.00
2. RSA Mustang P-51 (review here) @ $375.00
2. Larocco Audio Pocket Reference II mk 2 (availability unknown - PLEASE read entire review)
3. Headamp Pico @ $349.00
3. Meier Audio 2MOVE (and the older MOVE) (3MOVE @ $270.00)
4. RSA SR71 @ $395.00
4. RSA The Predator @ $475.00
5. RSA The Hornet “M” @ $370.00
6. Xenos 1HA-EPC (discontinued)
7. RSA Tomahawk @ $295.00
7. Meier Audio XXS / Headsix @ $166.00/187.00
8. TTVJ Portable Millet Hybrid @ $459.00
8. Decware Zenhead @ $295.00
8. iBasso D3 Python $219.00
9. Xin Reference @ $279.99
9. Meier Audio Porta Corda III (discontinued)
9. Xin SuperMicro IV (current version auditioned 1/22/08) @ $199.99
10. ALO Double Mini3 (review here) @ $235.00
10. Headamp AE-2 @ $349.00
10. Graham Slee Voyager @ $233.00 + S&H from UK
11. iBasso D2 Boa $165.00
11. Go-Vibe 7
11. Mini3 (Price depends on build) built @ $125.00
12. Leckerton Audio UHA-3 @ $189.00
13. Portaphile V2^2 @ $275.00
14. mSeed Spirit (discontinued)
14. Mini-Box E @ $229.00
15. Storm 3 (NOT B3) (review here)
15. Storm Little-2 (review here)
15. Storm B4
16. iBasso P-1 (discontinued)
17. Visely HEA- 1 @ $135.00
18. Microshar uAmp107 @ $135.00
19. Practical Devices XM4 @ $135.00
19. C&C XO @ $209.00
19. iBasso T2 (T4@ $109.00)
20. NuForce $99
20. Go-Vibe 6 (discontinued)
21. Xtra X-1 Pro @ $104.00
22. Xenos 0HA-REP (discontinued)
22. iBasso T1 (discontinued)
23. Xtra X-1 (discontinued)
24. C&C Box V2
25. Storm B3
25. Little Dot Micro+ (discontinued)

As always, this is JUST MY OPINION, but I hope it has been helpful.

[Headphile808]

Excellent update Skylab, still confident that purchasing the "P-51 Mustang" was the best decision I have made yet since joining Head-Fi. Thanks for all your help, could'nt of done it w/o you.
Aloha
Headphile808

[HK_sends]

Originally Posted by Headphile808

Excellent update Skylab, still confident that purchasing the "P-51 Mustang" was the best decision I have made yet since joining Head-Fi. Thanks for all your help, could'nt of done it w/o you.
Aloha
Headphile808

Ditto!

-HK sends

[HeadphoneAddict]

Originally Posted by Skylab

Update 1/4/09

HeadphoneAddict was nice enough to loan me the 3 following amps for review. While all three incorporate USB DACs, and I did very briefly listen to their USB DACs, the comments below refer to them being used ONLY as headphone amps, driven by my iMod iPod from their analog inputs. HeadphoneAddict has done the definitive review of these products as DAC/AMPs, and my review has only ever been about them as portable amps.

[snip]

> NuForce Icon Mobile

Nuforce, Inc

The NuForce Icon is incredibly light, and fairly small. It’s also very cheaply built. It has no actual power switch, but comes on when you plug in headphones – which I don’t like. It has a gain switch, which is hard to operate.

Build Quality: B-: See above. It was also fussy in terms of its headphone jacks. I know it’s wrong to expect much build quality from a $99 amp/DAC, but you sure don’t get it.
Treble: B: Piercing, bright, aggressive, and somewhat unclean treble compared to any of the better amps here. Not truly dreadful in absolute terms, but the amps main liability. Unless you have VERY dark, rolled off headphones, BE CAREFUL. The NuForce’s treble is kind of scary. Downright unpleasant with my Beyer headphones. Better with the AT ESW9’s, but they are pretty forgiving.
Midrange: B+: Slightly forward, and with a noticeable chalky grain. Decent, but not great. Vocals have some extra presence which is can be nice, but is not real.
Bass: A-: The bass was very good. Both powerful and deep. Not world class, but not as problematic as the above
Neutrality: B: Generally not very neutral. Forward and bright sounding. VERY careful headphone matching will be needed, and with something like the Ultrasone 780, it will be just plain awful.
Soundstaging: A-: Convincing image stability, and reasonable width combined with excellent depth give it a good score here.
Transparency: B+: At times it seemed very transparent, and with other material, it was not at all. The aggressive, forward sound signature just didn’t give the illusion of transparency.

I guess the best thing I can say about the NuForce is it’s cheap. But I didn’t really care for its sound. My recommendation is to save your money for something better.

1) I AGREE WITH YOU COMPLETELY ON THE D3 and D2 REVIEW. Like you, I also like the Meier Headsix/XXS a little more than the D2 boa. Then again, I also liked the D3 and TTVJ just a little more than the Headsix (though still a little below the Pico/Predator/3MOVE). We don't have to agree on everything, especially when the amps in 1st - 8th place are so close.


2) With the D2 Boa, I thought the mids colored female vocals a little in the low mids and on some headphones they were a little recessed vs the D3 Python. Based on your commentary about the D2 Boa and after I subtract the recommended half grade in each area, for D2 Boa I get:

Build Quality: A: Does this drop a half-grade too?
Treble: B+: It has the same basic sonic signature as D3 but has an even more noticeable lack of treble extension.
Midrange: A-: It has the same basic sonic signature as D3 but the mids are a little more colored.
Bass: B+: Less bass definition than D3.
Neutrality: A-: More colored than D3.
Soundstaging: A-: Less well defined than D3.
Transparency: B+: It was a little less clean, a little less transparent than D3.


3) With the Nuforce review I didn't think it was as bad as you did. I didn't feel the highs were piercing - bright and aggressive yes, but not shrill. I also didn't think the mids were chalky as much as they were forward and a little etched at times. With headphones that are recessed in the mids this helps bring out better midrange definition, like with D2000. Also, the case was redesigned to allow more headphones to fit, and anyone who bought from the first batch before 12/16 can get a free case replacement. Here is how I would have used your rating system with my feelings on the Nuforce.

Build Quality: B: See above. It was also fussy in terms of its headphone jacks. A new case is being sent to buyers who bought prior to 12/16/08 which will allow a wider variety of headphones to fit the recessed jacks.
Treble: B: Bright and aggressive at times, not as refined as some of the other amps here. Not truly dreadful in absolute terms, but the amp's main liability which makes it not my first choice for Grados, while not piercing or sibilant.
Midrange: B+: Slightly forward, and with a slight grain. Decent, but not great with the wrong headphones. Vocals have some extra presence which is can be nice to fill in the mids of some recessed headphones like D2000.
Bass: A-: The bass was very good. Both powerful and deep. Not world class, but not as problematic as the above
Neutrality: B: Generally not very neutral. Forward and crisp sounding. Careful headphone matching will be needed, and with something like the Ultrasone 780 it might be just plain awful. But with something like a D2000 which has less mids than the D5000 the match is much better.
Soundstaging: A-: Convincing image stability, and reasonable width combined with excellent depth give it a good score here.
Transparency: B+: At times it seemed very transparent, and with other material, it was not at all. The aggressive, forward sound signature just didn’t give the illusion of transparency.

Basically I told someone else the D3 is like a german Sport sedan (smooth and refined) and the Nuforce is like a quick hopped up japanese import (lively and snappy).

[jvlgato]

I had the very good fortune of spending some time at skylab's place (and what a nice place it was!); with a brief amount of time (about an hour) with my RS2's, I would lean more toward what headphoneaddict heard w/ the Nuforce. Nuforce not quite as refined in the mids and highs, a little aggressive and edgy, but not terrible, and very good in other realms. Considering its price and minuscule size, I quite liked it! I REALLY liked skylab's 2Move A LOT. I thought the iBasso's were fine, but I wasn't bowled over by them. A little too polite, a little lacking in detail, IMHO.

[jaykay]

Nice review as always Skylab. I really thought my head-fi journey was winding down..I figured the last move I make would be to send my d2000 to Alex for a recable job. However, the more I look into your review and HeadphoneAddict's, the more I want a 2move/3move. I loved my porta corda mkIII while I had it and actually do miss the sound. Perhaps I can get lucky and score a second hand 2move for a good price in the next month or so. Anyways, thanks for the great reviews on all the amps!

[HeadphoneAddict]

Originally Posted by jvlgato

I had the very good fortune of spending some time at skylab's place (and what a nice place it was!); with a brief amount of time (about an hour) with my RS2's, I would lean more toward what headphoneaddict heard w/ the Nuforce. Nuforce not quite as refined in the mids and highs, a little aggressive and edgy, but not terrible, and very good in other realms. Considering its price and minuscule size, I quite liked it! I REALLY liked skylab's 2Move A LOT. I thought the iBasso's were fine, but I wasn't bowled over by them. A little too polite, a little lacking in detail, IMHO.

I'm glad you got to spend the time with Rob and the amps, and enjoyed it. It makes it all worthwhile in sending them out there. Originally it was just going to be the D3 Python except for your wanting to hear the other two as well.

So, I assume you are now going to email Meier about whether they have any discounted B-stock 2MOVE available for sale?

[tseryan]

I read that the Denon D2000/D5000 don't improve much with amping. In regards to the Denon D2000, how did the Predator fare over the Pico? I'm having trouble deciding between the two amps having never heard either one. My source is my PC and my headphones are the D5000s, and since the amping may not improve my headphones much, would I be better off with the better DAC? Or do amps still change the acoustics of the music even if the headphone doesn't use all the power?

I have an iBasso D3, but the RF problem has left me in search of a different amp. I definitely notice that the DAC does make a difference in the audio quality compared to the on-board sound card. I'm sure the amp aspect contributes as well, but I'm mostly sure it's the DAC that makes the largest difference.

[HeadphoneAddict]

Originally Posted by tseryan

I read that the Denon D2000/D5000 don't improve much with amping. In regards to the Denon D2000, how did the Predator fare over the Pico? I'm having trouble deciding between the two amps having never heard either one. My source is my PC and my headphones are the D5000s, and since the amping may not improve my headphones much, would I be better off with the better DAC? Or do amps still change the acoustics of the music even if the headphone doesn't use all the power?

I have an iBasso D3, but the RF problem has left me in search of a different amp. I definitely notice that the DAC does make a difference in the audio quality compared to the on-board sound card. I'm sure the amp aspect contributes as well, but I'm mostly sure it's the DAC that makes the largest difference.

The D2000/5000 most certainly benefit from a good amp.

If you are using your PC as your main source, I would pair your D5000 with any of the top DAC amps like Pico, Predator or 3MOVE. All of them have a DAC that sounds better than the one on my Macbook or iMac 20" Intel. The D2000 and the MD5000 DE that I reviewed do very well from Pico and Predator, and I have tried the D2000 with 3MOVE and they do very well together also. But vs the D5000 my D2000 have slightly recessed mids which the 3MOVE helps to fill in a little (Didn't have 3MOVE to try with the borrowed modded D5000).

My personal choice for D5000 would be the Pico since the DAC is top notch and it gives them a very nice wide open soundstage with plenty of current output to drive low impedance phones without getting too sloppy. However, the 3MOVE offers the ability to run entirely from USB power without needing to keep it plugged into the wall or to keep a battery in it that will run down.

[Skylab]

Originally Posted by HeadphoneAddict

1) I AGREE WITH YOU COMPLETELY ON THE D3 and D2 REVIEW. Like you, I also like the Meier Headsix/XXS a little more than the D2 boa. Then again, I also liked the D3 and TTVJ just a little more than the Headsix (though still a little below the Pico/Predator/3MOVE). We don't have to agree on everything, especially when the amps in 1st - 8th place are so close.


3) With the Nuforce review I didn't think it was as bad as you did. I didn't feel the highs were piercing - bright and aggressive yes, but not shrill. I also didn't think the mids were chalky as much as they were forward and a little etched at times. With headphones that are recessed in the mids this helps bring out better midrange definition, like with D2000. Also, the case was redesigned to allow more headphones to fit, and anyone who bought from the first batch before 12/16 can get a free case replacement.

I don't expect us to agree on everything, although I think in the main, we actually do. I spent some extra time with the NuForce just to be sure of my findings, since jvlgato also liked the NuForce more than I did. This is what I thought of it. YMMV

Originally Posted by jvlgato

I had the very good fortune of spending some time at skylab's place (and what a nice place it was!); with a brief amount of time (about an hour) with my RS2's, I would lean more toward what headphoneaddict heard w/ the Nuforce. Nuforce not quite as refined in the mids and highs, a little aggressive and edgy, but not terrible, and very good in other realms. Considering its price and minuscule size, I quite liked it! I REALLY liked skylab's 2Move A LOT. I thought the iBasso's were fine, but I wasn't bowled over by them. A little too polite, a little lacking in detail, IMHO.

Nice having you over, and I was glad to get a chance to listen to the DACs with your set-up. I didn't feel that the DACs changed my feelings about the amps much versus the line inputs, although i do think the NuForce sounds better via USB than via analog.