Review: Portable amp roundup! 56 portable amps reviewed and compared - FINAL update 12-20-10... - Page 5  

Great review.

I'm surprised TH fans aren't up in arms about the Hornet M being higher ranked.

Awesome work! Just adding on...sticky!

I'm considering the Headphonia for my DT990. I still haven't decided yet, as it's between this and a Portaphile V2^2 Maxxed, but your review doesn't make things easier...

300th post!

Skylab, we can guess what you did on your Christmas vacation. Thanks for sharing, that'll be a "go-to" review for a while.

The only gotcha is that it really hard to get the amp gains well matched with an SPL meter. Different headphones will couple with the head differently, and its really hard to get repeatability acousticaly even with one headset (I have alot of experience in this area). Louder will sound better if all other attributes are pretty close.

What I do when running electronics comparisons is to match the amp gain directly. Cut a "reference" Cd with a few simple tones on it, then use a voltmeter to measure the amp voltage output into a resistor load (best to be equal to your headphones, if possible, so to best get equal levels if any amp has appreciable source resistance). A Neutrik terminated in the resistor will do the trick for a couple bucks.

If you want a really good (free) tone source to cut the CDs with, send me a PM.

x3 sticky it should be!
Skylab your hard work is obviously much appreciated by all (well all except Adrea maybe ) who have taken the time to read it. Thanks a lot for putting it together.

Nicely done Skylab! Sticky it should be, yes (x4)!

Can someone answer this question. When it's said that an amp is noisy, what causes this, is it cheap componets, maybe cheap construction. I have a LDM2(low gain model) that I use with my ZVM (line out) and a pair of UM2's. I always thought this amp was pretty noisy, there's a lot of hiss (to the point where it can be heard even through fairly loud passages of music). I know that UM'2 are fairly sensitive which probably doesn't help. Would a better amp (say a hornet or a tomahawk) still have this hiss. Are they worth the extra money (this could be a silly question!).

Thanks in advance

Yes,the two amps you mentioned will definetly reduce the hiss, or even eliminate it completly, depending on the listening volume. I can even get my HD650 to hiss with the Hornet, but just in high gain, and at volume level that would make your head explode. So at low gain, you should be perfectly fine.
So the quote "no hiss" from skylab should be read as "no hiss at sane volume levels".

@Skylab: Great review, and shurely a help for all who are in the market for a portable.
One note though: As you mentioned the noice when turning the pot for the Little Dot Micro, it should be mentioned, that this happens with the Hornet as well, due to the pot in use. Not that new buyers think their new toy is defect^^

Hopefully they're pics comparing the size of the Headphonia and Practical Devices X4. *nudge nudge, wink wink*

-The Grinman

Thanks for the pictures.

Its great to compare the size of these and amazing how small some are compared to the battery.

Smaller is better Can't wait for my Tomahawk to arrive. Personally, I'd class the Hornet as just about the maximum size I'd be willing to carry outdoors

w00t great review skylab.

Interesting. Mine don't hiss at all.

IMHO it should be noted that the Practical Devices XM4 has socketable OPamps. Its a dual OP amp design with one chip buffering the other (I think someone please correct me). I think its the only one in the review with this feature. Would it be possible to update your review with some commentary, on which amps have socketed OPamps and which do not?

What that means is the chips can be rolled for a custom sound that synnergizes with many different cans.

I wouldn't be surprised if it could rank higher on your preference list with a little OP amp rolling.

Thanks again for an excellent review, Mods cast my vote for a sticky.