Portable amplifier for the ipad?

Question

Hi all
I only had my ipad for couple of days and liked it so far. However, I'm disappointed with the sound quality of the ipad, the sound does not feel as alive and natural as my old itouch and the sound of different instruments seems be squished together. I also get white noise when turn the volume up to full.
I know the problems is due to ipad as the music is encoded in apple lossless format using the original CDs and I'm also using Sennheiser IE8 headphone with many hundreds of hrs of burn in.
There is also quite a difference when using the same headphones to play the same format of songs on my macbook. So I can only conclude that the DAC chip in the ipad is not as good quality as it should have been for the price.
Anyway, can anyone please recommend to me a portable amplifier for the ipad. My budget is about £200, and if possible I'd like to be able to use it with my macbook as well.
Also I would like to try it out before buying, so can anybody suggest any audio shops with a good selections of portable amps in London that can be easily reached using the tube.
Thanks guys

Answer 1

Hi, just an update on the ipad sound quality to clear the air for any partial buyers reading this thread.
I now had my new gears for 3 days and have used them to test the ipad music quality extensively over the weekend.
1st up is my new portable Nuforce Icon mobile (DAC/amp) and 1 year old Sennheiser IE8 connected to the ipad using line out cable.
The Nuforce Icon mobile is retailed at $99, and for that price I’ve no higher praise as it almost make the music life like to listen, there is also no more annoying white noise in the background when turning up the volume either.
The amp does make music sound a bit bass heavy, but I think that’s the fault of the IE8 and not the amp, as the IE8 is bass heavy to begin with.
I also used it with the macbook through a USB port, again the mini makes a noticeable difference with sound quality using IE8 to play apple lossless music.
If you already have a decent pair of aftermarket headphone or if you spend lots of time listen to music on your laptop. Than I’d highly recommend the Nuforce icon mini as it’s a great piece of equipment to improve the music quality without burning a big hole in your pocket.
If you are interested, there are many reviews of the Nuforce Icon mini on the head-fi.org site, much better than any I can write.
I also did some blind tests between apple lossless and ACC 320kbps encoding on the ipad using my new Sennheiser HD800 and Graham Slee Solo SRG II headphone amp.
Even with both the headphone and amp not yet burned in, I can hear no difference between the 2 encodings using ipad onboard DAC and line out cable.
So I replace the lossless music on the ipad with the AAC 320kps version and gained 2/3 of hard drive space.
I’ve to say the DAC in the ipad is quite good, as there are not much details lost when compared to my Creative Lab soundcard in my PC.
So I was wrong to assume the ipad DAC was causing the poor sound quality. I think there is a problem with my 3.5mm headphone jack. I’ve connected both my headphones and amps to it, and there is always some white background noise at different volume setting.