how much better performance are full sized vs portable amps

MUCH

There isn't much comparison. If you haven't read Boomana's Wiki for new users, you'll find a good explanation there.

It mostly boils down to power. Battery units (at least compact ones) won't give you the kind of power that comes out of the wall, Off the mains, you get 120V and plenty of Amps. You need that if you want to drive high voltage (like tubes) or want really good class A performance. Another factor is that good class A runs hot. Even if you managed to put that kind of power into a tiny case, it'd be too hot to hold and you would not want it in your pocket.

I don't have much use for portable amps. If you're using IEMs, they're usually fine straight out of an iPod or other DAP. If you want to run inefficient full-sized headphones, you only get enough power from a desktop to really make them sound good. Besides, you don't want to go outside with the big headphones, they're inconvenient. IEMs are better for being mobile.

If you want an amp that is transportable, there are several compact desktop amps that you can put in a briefcase, luggage or backpack easily, then plugged in when you have a place to listen.

This!

Most of them are not even on a comparable level..

Coming from a purely factual standpoint the lack of size and power restrictions in a desktop amp allow for much more power and hardware. As an example comparing only the power output capability....

 

The high performance version of the AMB Mini3 can do about 0.3Wrms into 33Ω whereas the AMB M3 configured with AD8610 opamps and a 27V PS outputs 0.6Wrms into 33Ω; configured with OPA604 opamps and a 40V PSU it outputs 1.8Wrms into 33Ω.

Edited by Nebby - 8/26/10 at 10:11am

like some of folks said on above posts, no comparison EXCEPT if you pair jh13/16 to pico slim then my money is on jh13/16+pico slim combo (short of really high end gear, ie HD800+WA22+really really good source)

The same difference as between these two cars.

 

 

To the novice not a lot. I had a Xin Macro first and dropped north of $2k on a nice tube amp. Initial test track, 701s at the ready and WTF!!!!! Is this all?????

 

After a few years of getting to roll tubes with my headphone I can say a desktop does all the little things better with less volume. The ease of presentation and extended dynamics that a larger power supply provides draws you deeper into the music. If you don't listen that way now, it wouldn't be of much value.

 

Man that Lambo is sweet.

Edited by Happy Camper - 8/26/10 at 8:23pm

What about "desktop" amps that run off wall warts? Often these wall warts step down the power into battery-like levels (e.g. 9V 0.5A DC), would these be considered the same class as portable amps?

power is the important thing being discussed,but not the only thing.

This is an interesting topic. Someone should do a blind test to settle this debate, shootout between LISA L3, RSA SR-71B & 2Stepdance vs Burson HA-160, GS-1 Headamp & WA22. etc

Portable amps are good for certain contexts but if you want something really nice with a nice solid tone that has more meat, you must have a big home amp. I once compared the portable Hornet amp to a vintage Marantz receiver's headphone jack. The big Marantz easily beat the portable amp. The tone was richer and more deep in flavor. It's like comparing a cheap chocolate candy bar to really good deep and dark chocolate cake. I say have your cake and eat it.

In my experience, desktop amps completely destroy portable amps, though some portable amps are still pretty good. For example, one of the best portable amps, the RSA 71b which is 650, is quite soundly beaten by cheaper amps like the schiit lyr. If you want something balanced, then the littledot mk6 and 7 which are very good value for money also completely outclass the 71b.

desktop amps are way better, i have a starter 300 dollar SS amp which i purchased as an upgrade from a NuForce Icon Mobile (79USD or so) and the difference was night and day, so much more power, way cleaner

 

the portable amp only raised the volume a tad bit, did a good job on iems, but still the sound quality was bad, everything sounded very thin and grainy. it was ugh, bad.

I had a Headroom portable Micro and a Gilmore lite at the same time, you have more room for buffer caps, power filter caps, things like toroidal transformers, input and output buffering, and all the other things that make stuff sound clean...