The tascam DP-24 and its predecessor the 2488 neo both allow you to, I suppose essentially, bypass the preamps by running balanced line inputs into the inputs on the back of the device. The audio may still be running through the preamps though, with no gain being added.
I record to a 2488 neo, and I use a good pair of outboard preamps, which I've been very happy with. I used to record to Tascam DA-38's that ran into an analog board, but when I went to upgrade, the next higher price point for outboard hard disk recorders was too much cash. Nowadays, the HD24 is not available new, and I don't trust the used electronics market enough to get one used. The only option these days is a handful of Tascam 48-track outboard hard disk recorders, but with all the necessary equipment, those run 5-6k alone, and then you need a 48-channel mixing desk for monitoring/mixing.
I'd check out the Tascam dp24, since it gives you 8 simultaneous inputs, 24 tracks of playback, and 255 total tracks per song to store audio material on (you can record 255 tracks of audio and export them all for mixing in a DAW - the only limitation being that you can only assign 24 of those tracks to the physical faders on the device at one time)