Eddie Kramer Master Tape Plug-In User Guide
Table Of Contents
http://home.comcast.net/~mrltapes/mcknight_flux-and-flux-frequency-response-
measurements.pdf
Flux is the
magnetic density recorded on the tape per meter (nWb/m),
the higher the flux
level - the higher the recording level on the tape. In order to reach higher recording
levels you need to have tapes that can manage a higher flux level (many modern tapes
can reach very high recording levels with minimum distortion with the added benefit of
reduced noise or ‘tape hiss’).
The manufacturer initia
lly established a recording level for recordings made on their
machines d
uring the 19
50s. This w
as called Standard Operating Level. This recording
level was at a flux level of 185 nWb/m. All early alignment tapes were Standard
Operating Level or 185 nWb/m signals and eventually became the standard for all
magnetic tape recording. As tapes were developed to handle greater and greater flux (or
higher recording) levels, the industry continued to rate tape flux levels based on the
original Standard Operating Level. For example, a tape that was designed to record
signals at 250 nWb/m was said to be recording at +3 dB (over the Standard Operating
Level of 185 nWb/m). As a point of reference, since the Flux Control on Kramer Master
Tape is calibrated in nWb/m, here is a quick reference guide for comparison (Source
Quantegy):
-2 dB = 150 nWb/m
0 dB = 185 nWb/m
(Sta
ndard Operating Level)
+3 dB = 250 nWb/m
+5 dB = 320 nWb/m
+6 dB = 370 nWb/m
+9 dB = 520 nWb/m
Science aside, early on many engin
eers discovered that by pushing or abusing the
recording le
vels on tapes, it created
some very musical and
frequently desirable side-
effects, especially in Rock and Roll recording. Tape has a very unique way of going into
saturation or overload, whereas digital is basically ‘go or no-go’ with over-modulation
producing clipping. As the levels are raised on analogue tape, a number of things
increase simultaneously and fairly gradually: Total Harmonic Distortion (THD), Inter-
modulation Distortion (IM), Modulation Noise and a mix of other aberrations and for ms
of distortion, many of which are still not fully understood. Also, when tape is pushed hard
enough, it has a tendency to ‘saturate’ which is a form of compression, unique to
analogue tape. Many engineers, even when digital was available, still preferred to record
certain instruments on analogue tape (especially Rock and Roll drums) pushing the
levels on the tape well beyond their ideal operating conditions to gain this saturation or
compression.
Modeling this behavior of changing sonic behavior across a
wide range of flux levels was
perhaps one
of Waves’ biggest cha
lle
nges. Ultimately they were able to create a
continuous flux control that ranges from -2 dB below the Standard Operating Level well
into unknown territories, invaluable for a wide variety of special effects.
Since 3M Scotch 207 w
as rated at between 185 nWb/m or 250 nWb/m
(while opinio
ns
vary about t
he ‘ideal’ level for Scotch 207, Waves chose the more conservative level of
185 nWb/m for the Kramer Master Tape default, although they modeled a wide range of
flux levels to be able to accurately create the variable flux control), you will find that the
Waves Kramer Master Tape
User Guide
18