This is a bit of a weird question I guess but anyway, theoretically speaking, say I've recording 8 tracks on my tascam 488 cassette and have transferred them to my DAW. I want to overdub a guitar solo, for example, but isn't the track now going to be slightly out because the tape speed isn't 100% accurate?
So here's an easy way around that *IF* you don't want/need the overdubs to be in sync with the original tracks on the 488. IOW...you're going to only focus on what is in the DAW once you dump it to the DAW from the 488.
OK...so you have 8 tracks form the 488 (let's assume these are your rhythm/bed tracks...and you've dumped them all into the DAW at the same time, as individual tracks (I'm assuming you have at least an 8-channel A/D converter interface).
Now you want to overdub another track (lead, vocal, whatever)...and you want to hit the 488 with it so as to keep everything sounding "tape-like" before you dump to DAW...but, your 488 and DAW are not rock-solid, synced together...so you can try moving/adjusting after the fact...or, you can do this.
Set up your DAW to playback the original 8 tracks.
Arm one track in the DAW for recording your overdub.
Arm one fresh track in the 488 also for recording your overdub.
Set that track so that the Playback head output of that track is feeding the armed DAW track.
Now...you hit Play/Rec on the DAW and Rec on the 488.
You are listening to the DAW for cues (NOT the 488) and your live overdub signal...but your playing/recording "through" the 488 for the overdub track.
The only thing you then need to do is compute the time difference of the Rec and Play heads of the 488 in ms (or samples)...and in your DAW, slide the overdub track by that amount. Tape drift will not be an issue anymore.
If your 488 has a single Play/Rec head...then you don't even have to slide the overdub track...it will be already lined up.
You can keep doing that as much as you want....overdubing "through" the 488...but actually recording TO the DAW.
In a nutshell...this is a poor man's CLASP system...where the tape deck is treated like a "processor" rather than a recording deck.