The following was written by Jason Woods and posted to the Nancies mailing list sometime in early 1999. I thought it was a very comprehensive guide on grading analog tapes.

-kaiyen
1.28.99

*WOODSY's GRADING GUIDELINES*

This is all based on two things. First, the grading that everyone is
used to (or a majority is used to) in school. A is
outstanding/excellent, B is above average, C is average, D is below
average and F is a complete waste of the emulsion on the tape. :) big
words, sorry...

The second basis is on what I consider the two big "losses" involved in
analog.
  1) Hiss
  2) Low Levels

Both of these are important to having a listenable and enjoyable analog
tape.

What about plus-es and minus-es?
A wavering. Almost there, but not quite. It's obvious, and can be used
at grader's discression.

*AN "A" TAPE:
   Contains a minute (little if any) hiss. you can get the volume to
about 70% and only then will you hear a slight hiss.
   Levels peak "in the red" at +3 db.

*A "B" TAPE:
   There is a more audible hiss present. If you have adjustable treble
controls and you turn them up, there is a noticeable hiss. It's not in
the way, and doesn't detract from the music, but its there.
   Levels peak between -3 and 0 db.

*A "C" TAPE:
   What your average tape sounds like. There is a hiss there, but its
able to be forgotten. You can still hear the music clearly, and its
still enjoyable to listen to.
   Levels peak at -3

*A "D" TAPE:
   You're starting to lose the enjoyment of hearing music because all
you hear is "hsssss". The hiss in a "D" is dominant over the music.
You're not having fun anymore.
   Levels peak at -6 db.

*A "F" TAPE:
    More hiss than your "D". You need to turn the volume to extreme
levels to hear anything resembling music. You begin to swear when you
put it in your deck.
    Levels peak at -10 if they show up at all.

OTHER FACTORS:
    This is where your plus-es and minus-es come into play. Song cuts,
channel dominance, fading, weird tape noises - all these things can
bring about the use of the plus and minus. You can also use them at your
discretion, and I don't know what that is :) It might be nice to note
the reason for a plus or minus when one is given in a comments section
of your tapelist. Just a thought...

-----------------------------

Conclusion. The tapes i got that were rated an A- and an A were, in my
opinion a D (A-) and an F (A). That sounds harsh. It should be. They
sounded like crap. I would not let my friends hear them, because they
become an inaccurate representation of a live experience.

More time should be taken with grading, if you're going to take the time
to do it. Don't just grade something an A+ because you know some poor
schmuck is gonna want to trade for it. Eventually, you will obtain
something that IS an A+ and is worth trading. There are many many tapers
out there making really nice tapes. CD Trading is gonna hpefully make
Analog trading even nicer and higher quality. I have very few tapes in
my collection that I would give the A rating to. I've got 51 DMB and D/T
shows, and I believe I give 4 of them an A rating. They sound fucking
great. Got lots of B's and lots of C's. I love to listen to them. They
sound fine. Not perfect. There are flaws, but I can get beyond them.

I'm in the process of redoing all the grading of my list. That means
going through each tape and checking for things like hiss, levels, cuts,
and channel even-ness. Its a great time, and I'm enjoying it.

I encourage everyone who has a tapelist full of A's and A+'s (and that
one fuck-head kid who had a copy of 2-19-96 that was an A+++++++) to go
over them and really honestly grade them. Feel free to use my method,
post it on your list, whatever. I don't want credit or anything, I want
tapes that i can listen to.

thank you one and all.

Jay