the best way to record to tape is with a tape recorder that has actual tubes in it or feed the signal through a good tube amp before the tape. that way you will be recording electricity to electricity instead of 1'a and 0's to electricity. the idea is to saturate the proper frequencies you want on the tape without losing low end response or adding distortion. easier to control when you go from analog to analog. most tape decks have meters that read in rms...you can go in the red a couple decibals while recording without distortion since analog gear is all designed to have headroom above the zero meter...its a completely different measurement that a peak meter (the meters you see on digital, or computer programs). it measures basically the average of amplitude in the electricity going through it.
also you can use lo bias tape or normal bias....but no matter what the signal quility WILL suffer. normal bias tape only has 60 db of dynamic range if brand new. that is the same as the human voice approximately. thats what it was designed for and is a slowly forgotten tool to helping you record "good warm" vocals. something you can hear lacking in most vocal recording these days.
hi bias is where its at though if you want to put a whole song on tape and give it a good saturation without dulling all the upper frequencies. hi bias has a dynamic range of 80-to 100 db....closer to a cd which is able to capture most of the upper harmonics of an orchestra. very important also if you plan to record synths to tape i feel.
hi bias is increasingly rare and very hard to find for reel to reel. so if you find any...keep it forever haha.
one thing to mention is reel to reels all record at a much higher speed than most decks also increasing dynamic range.
it would actually be best to find a high speed cassette recorder and use it with high bias....i myself have never had the chance to use a high speed cassette recorder....exp, and hard to find.
with all this said you can still achieve real grimey results with a shitty recorder, and shitty tape...its all just fun to experiment with anyway!
one little trick is using overdrive effect to control the frequencies that saturate. thats all i will say about that though cause its kinda a technique if you dont know, READ UP! hahah
theres lots of info out there about it to feed on.
im not just talkin out my ass here either...i have taken analog recording and and live anolg recording classes and i could break it donw to electrical measurements if i wanted to haha.
i have also don lots of tape mastering on reel to reel for people so get at me with any questions. peace