I have one of those. I haven't used it a whole lot but it seems to work ok and the price was right.
the instrument input is a couple of milliseconds behind the track audio
Yes, the dreaded "latency" problem. One good reason why so many go with a dedicated recorder despite the attractions of using a computer. It gets discussed a lot.
One interesting fact is that sound travels through air at right about 1000 feet per second, so a 10 ms lag is like being 10 feet away from someone you're playing with, which isn't uncommon. A few milliseconds shouldn't be much of a problem but 50 or 100 ms is.
just need to get the right levels on everything.
Design flaw or feature, you decide, but there's no level or gain control between the box's input and the analog-to-digital converter. That means you need to control the input level some other way before it gets to the interface to get a reasonable signal level without clipping.
That's different from what most of us are used to with computer sound cards, where there's usually an on-screen control that sets recording level. I'm always coming from something with an output level control or going through some kind of preamp, and the stuff I'm using is probably better than whatever circuit they could have added inside a $30 box. It hasn't been a problem once I learned why it's that way.
Seems they spend most of the money on a pretty decent converter chip, which makes sense to me. It does what it does and overall I'm happy to have it around.
