Is this a problem?
 

I just bought a minidisc deck with an optical output. The USB interface that I also bought will only sample at 48 kHz and the minidisc is 44.1 kHz. The problem is that I can only seem to get my computer (it's a Mac) to capture at 44.1 kHz. It just doesn't seem like a good idea to upsample the signal and then downsample it into the computer. Is there any downside to this? I'm considering sending the USB interface (it's made by Edirol) back, or am I worrying too much about it? It just seems like it would be better to capture at 44.1 kHz and then add dither when I upsample to 48 kHz to make the AIFF file.

What are you using it for? If you are recording classical or pure acoustic music, you *might* notice a difference, but chances are you won't notice anything with the upsample.

I am not an audio technician and am not familiar with your Edirol unit. (I have an HHb PortaDisc.) But I can at least offer what I do with MiniDisc.

I use the USB interface to perform captures into my Mac (G4) desktop and Powerbook through Peak.

I thought that MiniDisc can only sample at 44kHz (i.e. CD rates), not 48kHz. In any case, my material always comes in at 44kHz. I just use Peak to up-sample to 48kHz and export to an AIF for use in FCP4.

I hope this offers some guidance to you, Marco.

This is just for dialog.
Ken, as you said, MD is 44.1. Basically what's happening is I'm starting at 44.1, converting to 48, capturing at 44.1, and then upconverting yet again to 48 to make an AIFF file to use in FinalCut Pro.
It sounds fine, but the anal retentive part of me that insisted on buying a separate deck in the first place thinks this is crazy.
I don't have "golden ears" though, and Douglas if you don't think upsampling twice is that big of a deal, maybe I'll just live with it.