M-Audio Firwire pres vs. Grace 101

[twilight engine]

I bought an M-Audio firwire 410 a while ago, and until recently never attempted using its on-board pres. I assumed they *had* to be crap compared to a Grace 101 and a vintage tube pre that I had.
Recently however, I had to sell the Grace, and I decided to see what the 410 preamps were all about since I might have to use them in the Grace's absence. I found that, to my ears, the difference between the sounds recorded with the Grace and the 410 were negligible, and in fact may have only been detectable by me because I *knew* that two supposedly different qualities were in play.
To make sure I wasn't hearing what I wanted to hear, I recorded several tracks of vocals and acoustic guitar with both pres (using an audio technica 4033 -- the only mic I had left after a selling spree) and had a friend switch them around in Cubase so I wouldn't know which was which. When I finished the test, I *kinda* felt like I could hear a difference, but I had no clue which was which, and absolutely no idea which sound I preferred or felt was "better".

So here's the deal: do I just not have an ear for recording, or bad hearing in general? Is the mic I used the only issue (grace is gone; i have new mics but can't compare)? Are the preamps on the firewire actually pretty good?
What's the deal, because if differences between supposed high end products and cheaper ones is so slight, then I can really save myself money in the future.

I'm new, by the way.

 

[twilight engine]

Fir-e-wire

Sorry: don't know why there're no e's in the "fire" portion of firewire.

 

[DJL]

Sometimes the differences are little... but it's also the little things that make a big difference... with experience one develops a trained ear... and what, where, and how your listening will make a difference too.

 

[Sklathill]

I think one of the things that makes the Grace 101 that makes it so much better than, say, my Behringer pres, is how damn good it makes some of these dynamics sound. My Marshal V67B sounds very similar between my Presonus (with no drive added), my TFPro, my Behringer rack (yeah, I have a whole rack of them, sue me. ), and the Grace 101. OTOH...the Shure SM7 sounds fantastic through the Grace, excellent through the TFPros, decent with the Presonus, and terrible with the Behringers.

I'd say with your 4033, the differences in the pres are less noticeable, and if you put in, say, a ribbon, a handheld dynamic, a large dynamic...you might hear the differences in the pres better than in a hot condenser...

...And it could be simply that you need to exercise your ear more, as DJL says. That's certainly an important part of learning the art of recording...