I think we've done this before, but it's almost 2009, so let's do it again. I know I've upgraded a few times since the last tread on this topic.
I use a MOTU 828mk3 which I purcahsed a few months ago, replacing my older MOTU. This is probably considered a high-end box to use for quad conversions when compared to a PCI card or Sound Blaster type board (I'm sure there are also many more expensive options out there), and maybe it's a bit "overkill", but I really like the flexibility I get with it. In the past, I've used boards from the likes of Yamaha, M-Audio and a few others, but this one takes anything I throw at it. It works perfectly with Vista as wel as XP, and all of my recording apps fit the MOTU ASIO driver without issue.
This device plugs into a firewire port on your PC, so if you don't have one, you have to add one. Using firewire makes passing the HiRez audio signals to the PC a breeze, and this box can do multichannel 24/192 if you want it to.
It comes with a control app called the CueMixFX applet. This allows you to do a ton of stuff with the incoming audio. I have yet to even try anything but adjusting the levels of the incoming sound by channel, and this is the main reason I went to my original MOTU in the first place. Back when I had my Yamaha and M-Audio boards, there was no way to adjust the incoming audio level by channel. Today's apps may allow that, but it was the selling feature for me that sold me on the unit.
As you can see from the jpeg of my desktop below, if you look closely at the CueMixFX applet sitting on top of Vegas 8.0, the level controls for the first 4 channels are all different. That's because I'm putting to HD a reel that I recorded 30 years ago from a Q8 that, at the time, I did not pay attention to the recording levels. (What the hell was I thinking!! ) Anyway, by being able to adjust the audio on the PC, it allows me to do each channel on its' own. I can't do this on my AKAI 630DSS, because the fronts and rears are grouped together on two output level controls.
So, for those interested in a higher than average priced sound solution for recording quad tapes and discs to your PC, I can highly recommend this device. It's also a great way to make 24/192 stereo DVD-Audio discs of the recent audiophile LP releases that seem to be making their way back to the market.
Now, how about some of you other guys posting about what you're using so the membership can get an idea of what they can use. You'd be surprised how many PM's I get from members asking "What can I use to do quad conversions?"