Manley TNT MICROPHONE PREAMPLIFIER - Manual (Page 6)

BEGINNINGS
The TNT project began due to requests from fans of
the SLAM! and in particular Lynn Fuston of 3D Audio
Inc. The request was simply “Can you bring out just
the SLAM! Mic preamps without the Limiters and
other features. Then came the 3D Audio bulletin board
“Dream Pre-Your ideas wanted” thread which had a lot
of great ideas and diverse opinions. Perhaps the most
obvious theme was that engineers were now using
several mic preamps at their disposal for a variety of
colors like they had always done with mics. This was
actually a pretty new trend in ‘92. How about a box
with a few different preamp topologies for different
sounds?
We began to experiment with some simple discrete
preamp design concepts and breadboarded a few
approaches. Hutch also had developed the “Rapture”
gain stage intended for a proposed digital converter
that was impressively un-colored and which became
the standard against which other ‘experiments’ were
compared.
Then the 3D mic preamp summit “Preamps in
Paradise” happened January 2004. This was a
historic event in Tennessee with a panel of 10 notable
preamp designers, and 7-10 famous engineers known
with reputations as preamp connoisseurs. Amongst
fascinating stories and a sharing of approaches, this
designer was hearing a chorus of requests, a short list
that included “variable impedance – but minus the
typical gain changes” and “some new useful control
or knob”. Up to then, the solid state preamp we were
working on was envisioned as a typical minimalist ‘2
knob’ discrete channel in some ways similar to the
tube side borrowed from SLAM!. But the engineers
were asking for more control, and were describing
approaches based on sonic characteristics such as
clean / not so clean, bright / not so bright, transformer
or transformerless and this resonated with the
designer’s session experience. Designers talk about
discrete topologies, tube types and transformer details
but recording engineers talk about sounds and controls
and session techniques.
The initial concept of the TNT was to put two very
different mic preamp technologies in the same box,
and that each were to be as simple as “plug in a mic
and it sounds fine”, without a lot of controls to get in
the way. In the end, the TNT did get new features and
controls such as the IRON knob, 60’s - 70’s switch
and its unique impedance control. And these were
largely due to engineer’s requests from the “Preamps
in Paradise” event.
At the 3D Preamp Summit, the topic of “vintage-
style” electronics came up, not because of huge
desire from the engineers but more as a designer topic
relating the headaches of recreating transformers and
obsolete parts accurate enough to be comparable to
the original. However where there was interest in old
school style was when the recording engineers began
to talk about how they did those classic 60’s sessions,
and the focus was on production technique and war
stories rather than components and gear. Maybe the
engineers were saturated with recreations of old gear
and were craving both the magic of old sessions and
yet new exciting toys to do their job with tomorrow.
A bit of both.
So we went back to the ol’ drawing board and back
to the lab bench and experimented with a variety of
circuits and topologies, but this time holding truer to
the end result the user would appreciate rather than the
internal workings that might have buzz word appeal.
Already the SLAM! preamp was not “all-tube” but
more of a hybrid FET-Tube cascode, so why stick to
“all-discrete” or “vintage-clone” when the engineers
seemed to be just concerned with sound or tone and
occasionally hoped they could get a few new controls
if possible.
The TNT solid state side evolved into a mix of discrete
and op-amps, plus it ended up with the Rapture Amp
for the line driver. Why this mix? Just our decision
based on listening comparisons where our choices
generally favored the cleaner or most true to the source
as a base. The users could always add stuff that gave
some color or texture onto that base and we provided
a few too.
We did come up with a few controls that gave some
possibilities for “tints” or “flavors” that could be dialed
in. For the most part these were designed to be subtle
rather than drastic because the TNT is a mic preamp
and not an EQ or a typical processor. In fact even the
IMPEDANCE switches were designed to not mangle
the sound in unintended ways - they should be “just”
impedance controls without baggage. Some users may
expect bigger sonic changes from huge impedance
changes or major audible effects from varying the
IRON content, but the folklore surrounding those
ideas is maybe more dramatic than reality. These
controls were designed to reflect reality which seemed
appropriate on a high end Mic Pre and tend to be more
like tweaks and trims. And this was more in line with
the original concept of a basic good plug-in-a-mic-
and-go preamp.
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