Why not record the tracks on your DAW,then submix from DA to fresh tape on the r2r,then sum to stereo?This would give you the advantages of hard disk,with instant ff & rw,undoable recording,punching,save wear and tear on the tape and the machine,as well as give you analog summing.
I realize your summing mixer,and DA may not be ideal for the job,but it will give you the analog warmth you would get with the Fostex,and the benefits of hard disk recording and mixing.

That makes sense, although the main purpose is to be able to mix using outboard gear and utilizing the EQ on the mixer. It's got a great sweep and I like actually turning knobs....could I still do this with what you suggested or would I just be mixing in DAW, recording to tape, then going stereo out back into the DAW? Thank you!

Beyond the 4 subgroups, The 300 series, as I recall, also has direct outs per channel. It also has inserts. So, you could always insert outboard processing and then D.O. each channel/tape return to your respective DAW inputs.

edit: What I don't remember is if the D.O.'s are pre or post inserts, although I think they are post. LOL.. it's been about 30 years since I cooked on that desk.

-d.

when you don't slam the tape at levels like +4 you really aren't getting much in the way of tape compression which is what going to tape is all about.

the early Fostex machines are pretty much unusable if you don't use the N/R. later versions like the G16s were pretty ok if you ordered them from the factory to run at 30 ips, you could actually record with the N/R off and get something useable.

with these machines when you use N/R, it's really best to keep levels under 0dB because over 0, you start inducing coding /decoding errors. even more true with DBX machines as dbx is broadband and is always in the path regardless of level. Dolby only affects the problem frequencies and slides in and out depending on level. more elegant.

it's a bit more complicated that this but a simplified explanation of how Dolby N/R works is (in part); by compressing portions of the audio band and applying a hi freq boost at recording at lower levels when tape hiss is most evident. the process is only applied when levels are below a pre determined threshold so at higher levels it kicks out. in playback the process is reversed. so accepted practice when using N/R is to keep levels below 0dB so you don't encounter decoding errors and over saturate the tape with high frequencies because remember, you have as much as a 10 dB boost of high end through the Dolby. Dolby A is a 4 band system. Dolby B applies single band processing where Dolby C and S apply independent multi band processing. SR is the most complicated with other tricks besides compression and frequency boost / cuts.

dbx works much the same but it is simpler as it boosts highs during recording and compresses. on playback it expands and cuts highs. it does this across the whole bandwidth and has a major effect on the low frequencies causing bass to sound mushy because of reduced attack characteristics. it is very common practice to switch out dbx on bass tracks. another problem with dbx is modulation noise where you can hear a low level "whooshing" as the signal rises.

another consideration is the frequency response of these narrow gauge machines is + or - 3 dB ... that's a possible 6 dB's of difference which is quite a lot ... when you add N/R to the equation you are looking at in some cases, a doubling of this effect so we're talking about plus or minus 12dB. WOW! that's pretty ragged in comparison to a large format machine which runs at +1dB - 2dB or better!

last the reliability of these machines is iffy. keeping the tape path clean and the heads aligned is an issue. adjusting the bias and calibrating is difficult as these are 2 head machines so the calibration process requires you to play back to verify levels, do an adjustment and then play back to verify levels and so on where a 3 head machine can be adjusted on the fly while recording a ref signal. the leds on these fostex machins tend to crap out and you cannot get replacement parts so at some point your recording blind.

my advice is to find a Tascam 38 in good condition or even better an Otari 1" 16 or 1/2" 8. i would lean towards the Otaris as they can be operated at plus 4 solving a lot of interfacing problems.

The Tascam mixer is another issue.. it's a hiss factory, has limited aux sends and really don't sound good enough to go to the effort to use them.

anything you do in the box will sound much better than using these 2 pieces imo.