Help! my ipod line out sounds horrible >.>

Hey guys, I just got a cheapy line out cable from fiio for my ipod touch.  Previously to getting this, I have simply been using the double male ended 3.5mm cable that came with my fiio e5 to connect it to my ipod touch.  I would then have my e5 on close to max volume and adjust my ipod to a suitable listening level.  When I tried the line out drive for the first time today however, I nearly blew out my eardrums because I still had my e5 at max volume level.  In fact, when I took my headphones off they were blasting so loud they were like speakers and probably could be heard all the way downstairs.  The only way for me to get a normal listening volume is to have the e5 at 1 notch above mute.... and it sounds absolutely horrible, probably even worse than if I were trying to play music off of a gameboy color or something. 

So I must be doing something wrong right?

Well, I tried restarting my itouch.  For some reason that seems to work, but the line out is still really loud, and the effect is totally different from just using a 3.5mm cable.  My amp doesn't seem to be amplifying the sound at all, and is instead sort of limiting the volume, it would seem that all the juice is coming from the itouch.  It turns out the bad sq was due in part to the bass boost on my fiio e5, which has become totally useless paired with the lod since it completely distorts the sound.  However, when I use bass boost with the double male ended 3.5mm interconnect it seems to add the perfect amount of bass with minimum distortion.  Is this just because I'm using a cheap amp?  I still feel that something is wrong here.

I've also started noticing large volume differences between my albums.  On certain songs I need to lower the volume 2-3 clicks on my amp and on others I need to raise it a few.  The overall volume on my amp is also extremely low, I'd say I can only have it set to 1/10th of the overall volume before the music gets too loud.

By the way, maybe the sound isn't horrible.... it's just that the very first song I listened to with the lod happened to react particularly badly to it.  It still does and I don't know why, it's a 320kbps mp3 file but it sounds absolutely just downright bad with the lod.... it's fine with any other setup though.

Hmm, really weird, I used it some more and it's sounding much better now... except for that one song.  But I could swear when I first used it the volume was all whack and the sound quality was just ridiculous.  Anyways, thanks for your help, I suppose it fixed itself.