modeled after broadband tape saturation. WITHOUT THE
NOISE! Smooth clipping up to 20% THD.
programmable high frequency saturation
simulating the "softening" for which analog tape and
phonographs are known. This is the "Warmth" control
which can add the musical artifacts generated by classic
devices like NEVE, API, etc. These artifacts include
frequency "rounding", low order clipping & intermodular
distortion, transient clipping... and some other very
- One for tracking, one general purpose, one "bus"
compressor, and SPANK (see below). All LINKABLE! Classic
knee compressor sound that really grabs.
An additional limiter
that musically smashes the dynamic range, and can
be used to stop clipping before digital recorders.
There is a subtle knee followed by hard limiting.
with high resolution numbering - For easy readability
and repeatable settings. They also go to 10 1/2 .
indicator lights - A 0 VU LED and a "Pinned"
(5%) LED. No hard clipping until a few dB past "Pinned".
output and input
for eq-ing control signals.
calibrated, output level
- Allows speed in setting tape and live mix levels.
- it's almost impossible to get a bad sound.
height and light weight
- Two channels of classic sound in a small, extremely
and integrated combination - the best of speed/linearity
with repeatability. Hand tested & selected components.
All metal film and Roederstein resistors in the
audio path - top quality components, most being
high temperature military spec parts.
110/220 volt operation - Extra fuse provided
bypass - Know what it's really doing. All contacts
doubled up for maximum reliability. No internal
and 1/4" phone ins and outs
- XLR fully balanced, transformerless design, pin
2 hot. Changeable by user to pin 3 hot!
internal connectors, high reliability parts
and military grade switches and relays.
year unlimited warranty.
and features found nowhere else.
processing not readily available in our current
digital domain. New life for analog processing!
wired, calibrated in USA. Shipping weight 13.25Lbs.
is 2 Hz to 60 kHz in clean audio mode (+0, -3 dB).
- 110 dB from maximum output (20%THDsoft clipping)
to minimum output. Greater than 100 dB signal to noise.
Ranges between .06% and 20%
depending on mode and settings.
coupled Input and Outputs
- High quality audio caps used internally.
- Attack range 1mS - 200mS. Release range .05 sec
to 3.5 seconds. Attack and Releases are fixed by the
compression type selected.
Labs - Something Old, Something New
to FATSO Manual Index
is the Fatso? - - (Hmm, Not such an easy question!)
EL7 FATSO is a modern digitally controlled analog device
that offers many of the "musical non-linearities" exhibited
by the older tube, class A discrete, and magnetic tape
mediums. This two channel audio processor will musically
integrate frequencies and transients and increase the
apparant volume without actual increase in peak levels.
In addition, two channels of famous Empirical Labs compression
are provided. There are several compressor "types" with
fixed attacks and releases (if you want a fully controllable
compressor, you will need the Empirical Labs Distressor!).
Users can enhance & soften the sound of mediums
such as modular digital multitracks (MDM's), HD recorders,
Dat recorders, Ram Recorders etc. Mixdown engineers
will have an option not to use bulky, expensive, (and
often flaky) analog tape recorders to get the warmth
and sweet high end they've come to rely on for so many
decades. Owners of Adats, MDM's, RAM and modern hard
disk recorders can finally put a stop to complaints
about the "coldness" and "brittle edge" of their mixes
and instruments with the "rounded" and "musically non
linear elements" of vintage analog. Finally, audiophiles
can bring back the warmth and cuddly sound of LP's and
tapes to their CD players, and other digital reproduction
Back to FATSO Manual Index
Fatso's Four Types of Processing (Available on both
Generation and Soft Clipper (Distortion generation)
Frequency Saturation - WARMTH!
& Tape Head Emulation
Knee Compression - Empirical Labs Style!
Fatso for the first time
is straightforward. Either the XLR's or phone jacks
can be used. In relation to the phone jack tips, pin
2 is wired "hot" on the XLR's. But if you're using
the XLR's in and out, it doesn't matter which pin
is hot, as long as you're cabling is in phase.
If you use a single ended XLR output, leave unused
pin floating! Connecting all input pins is preferred,
but the unit will operate fine if unused pins aren't
tied to ground. Hookup directions are also located
on the rear panel of unit, near the connectors.
See wiring section for greater details.
is ideal for sources that sound brittle, bright, or
pointy or have excessive dynamic range. You will probably
find so many uses for the Fatso as we did, but ...let's
just go over a couple quick scenarios here. Let's
say you have a vocal either live or in the studio
that seems lifeless or needs presence and intensity.
First lets set the compressor up. In fact you should
always set the compressor up first because it interacts
with the other processors in the Fatso. For excessively
dynamic vocals I would go right to the TRACKING compressor
"type" with both the green and yellow LEDs lit in
the compressor select area. Adjust the input til you
get 5 dB of GR to start with and adjust the output
knob until there's not a great difference between
the bypassed and un-bypassed levels. Remember the
Bypass switch is multiplexed and to cycle in and out
of bypass, click twice quickly. Next decide if the
vocal has a brittle edge on the top end. If so, you
have two other ways to soften. The most subtle is
the Tranny which engages a specially tweeked transformer
circuit that enhances the midrange while softening
extreme transients and fattens 200 hz and below. That
may not be what you need on vocs tho. Try the Warmth
control for less subtle high end softening. This circuit
is a wierd dynamic filter not too far removed from
de-essing except it is above most sibilant freqs and
works on a different principle and filter type. (...ok,
so it is far removed!). This circuit is really useful
on vocs that are bright or have 10KHz and above boosted
heavily with EQ. In fact warmth is really useful used
in conjunction with high freq eq boost, as it will
only grab the parts that are excessively bright or
"plasticky" and get out of the way in less than a
millisecond. Use it as an EQ tamer!
you progress from 1 - 7 on the warmth control, more
and more high freguencies will be "grabbed" and eventually
you will start muffling the signal!!! DON'T DO THAT!
Be very careful not to overuse the warmth control...
1 - 5 dB of Warmth is a lot! By now that distant,
thin, vocal should be HOT and in your face. When using
the compressor and warmth together, remember the interaction.
Apply this same type of thinking to other sources/instruments.
Don't be afraid to use the warmth without any other
processing, or just the compressor, or just the Tranny
(to fatten low end). Also remember the unit is always
passing the signal through the saturation circuits,
with no LED's on whatsoever. Don't feel like you have
to use all the processing within the unit because
that will surely get you in trouble, sooner than later.
SEE EXAMPLE SETTINGS ON NEXT PAGE!
to FATSO Manual Index
Fatso was designed essentially to integrate frequencies
in a musical manner and provide some fool proof vintage
sounding compression. Generally, it is difficult to
make the unit sound unnatural due to its vintage topology.
But it is possible to "overdo" things! Let's go over
the four types of processing the Fatso provides, and
describe what they do and generally when they would
Fatso's Four Types of Processing
1) Harmonic Generation and Soft clipper - Basically
this is a distortion generator. Anytime you pass a
signal thru the Fatso, it passes thru this part except
in bypass. This processing is useful to softly but
instantly clip peaks and transients, allowing more
2) High Frequency Saturation - WARMTH! This circuit
is meant to simulate the softening of the high end
that occurs with analog tape. Basically as the warmth
is increased, overly bright signals and transients
will be quickly attenuated. The time constants are
very nearly instant, so the high freqs return very
quickly after a loud burst.
3) Transformer & Tape Head Emulation - This is
a simulation of the effect of input and output transformers
of older devices and adds the low frequency harmonics
that characterize analog tape. This is extremely useful
on pure low frequency type tones that don't cut thru
small speakers. It adds upper "warm" harmonics to
frequencies below 150Hz, especially those even lower
such as 40Hz, the low string on a bass guitar, helping
it to cut thru on smaller speakers.
4) Classic Knee Compression - Empirical Labs Style!
This is your typical automatic leveling device that
you find used on just about every instrument and vocal
track, as well as on the overall buss. Only its Empirical
Labs compression - smooth sweet but in your face!
(Reminds me of an old girl friend) See the compression
guide on page 6 for description of the 4 compressor
CD Player & Buss Fattening - This was almost
the original intent of the Fatso. That is, it was
a two-channel device that could make a stereo digital
signal sound "analog" and integrate the different
frequencies in a musical way. It could be used as
a stereo device thru which one could mix or transfer
to or from a digital medium to make it sound very
For those who aren't used to the Jargon... A BUSS
is usually a pair of channels that have pre mixed
instruments or stereo music on them. The Left &
Right outputs of your CD player could be considered
a 2 channel buss. In the recording studio, it is more
often applied to the final left and right channel
mix, or to something such as all the drums mixed down
to 2 tracks (a "submix), so that instead of moving
12 faders at once to move the drums up and down....
You only have to grab those two.
MIXDOWN PRE PROCESSOR
- Again, one of the original intended uses. By placing
the Fatso immediately before a digital mixdown recorder
such as a DAT, CD, HD, or RAM recorder, the recording
engineer should be able to get the sweet high end
and low frequency fatness that he could mixing to
an analog tape recorder. Compression should usually
be the Buss type, use the warmth to soften the high
end and the Tranny to add some edge and warm harmonics
to the Low frequencies.
CD PLAYERS & Other Digital Recorders
- Take the output of the CD player into the Fatso
input. Our first goal is to make that CD player have
the warmth and softness of the old tape recorders
and records. If you were going to use compression,
set it up first since it interacts with the other
settings. But for now let's not use any compression
here. First adjust unity gain thru the Fatso. Set
the input until the 0VU LED glows on peaks from time
to time. This will set up the saturation to emulate
some nominal tape like distortion. Next if you want
the low end to have more bite, the tranny may be useful
but for most digital recordings, try messing with
the warmth control. Allow 1 - 5 dB of warmth to occur
on peaks. When AB'ing it to the original signal, a
new softness and fatness will be noticed immediately.
You will be able to listen to things a little louder
level controller and master PUMP device
- Place the Fatso before your power amps or at the
output of your DJ mixer to level out or fatten up
the whole show. The Buss compressor can level out
volume differences while keeping the "smack" intact.
You can then add some top EQ and have the warmth
hold back the brittle edges. The Tranny may help
on smaller systems to get the low freqs clearer
but if you have lots of subsonic info... you may
want to keep Tranny out of line since it will roll
off the exceptionally low low stuff.
to FATSO Manual Index
EXAMPLE SETTINGS (part 2)
- There are so many ways to use Fatso here.
During tracking, turn on the Tracking Compressor which
lites the green and yellow LED in the compressor area.
This is a pretty safe LN1176 Type knee compressor
with a pretty quick attack and release. That might
be all you need! Using up to 10 dB of compression
should be fine with really dynamic vocs. Alternately,
you can try one of the other compressor types, even
SPANK to grab occasional peaks and then quickly get
out of the way.
the top end is too sizzly or spitty, you can try the
warmth control, maybe adding up to 6dB of warmth on
the peaks. This is not a de-essing function since
it affects freqs above the most troublesome sibilant
freqs, nonetheless, you may find it helps take some
of the hissy sound out of a source.
may be useful on exceptionally low vocals as it will
warm the low tones to some degree. It will also roll
the super subs off but generally, Tranny will not
radically affect most vocal sources.
- Fatso is gonna be really useful here. Bass
is notoriously hard to round out and clarify sometimes,
but the Fatso has many ways to help. First, if a low
bass tone is too pure and sine-wave-like, it will
"fall off" on small speakers. By this we mean, it
will not be audible because most of the bass frequencies
are below the range of the speakers.
The Tranny is the solution, combined with the saturator
circuits. These will generate upper harmonics that
will be musically related. These harmonics will
be reproduced on small speakers and the human ear
(and mind), will psycho-acoustically fill in the
lower fundamental! Great on direct bass.
Back to FATSO Manual Index
Fatso compressors are fabulous on bass too. The buss
compressor is good for an already compressed or very
evenly played bass, since it will leave the transients
and remaining dynamics in. It will also allow you
to use varying amounts of grunge since it is such
a gentle compressor that wont really nail the bass
level in place. Just by turning the input up, one
can add or remove distortion. The GP is another compressor
that may allow the dynamics to come thru but due to
the long release, excessive pops or plucks may create
"holes" in an overly dynamic bass part. The Tracking
compressor is a favorite again for bass (both the
green and yellow LED lit). It is the most Distressor-like
compressor in the Fatso with a fast attack and release,
along with a smooth knee. SPANK is useful for a more
aggressive level control on Bass.
As you can see, there are lots of options here!!!!
The warmth control may be useful for some trebly,
over eq'd basses, but generally it may find limited
use here. Again, watch for over smashing or grunging.
Caution should be observed if you are going to tape.
You cannot un-distort.
Elec. Guitar - A wide range of settings
can be used. To get rid of edgy attacks, use the quick
attack, fast release of the tracking compressor. If
the guitar is too dynamic, the compressor combined
with the saturator and tranny circuits may be the
answer. Sometimes the guitar just needs a touch of
fatness without losing attack, try the buss compressor
to maintain transients. Watch over warming guitars
with the saturators and the warmth circuits. Crunchy
guitars which are full of harmonics, are notoriously
sensitive to tonal changes. Over saturating or warming
can take away the clarity or bite needed to cut thru.
Other times, it's just what's needed to let the guitar
be louder in a mix and stay out of the way of vocs
because the upper, spiky, harmonics are flattened
a bit. When you are dealing with an occasional peaky
guitar where certain chords or notes take your head
off, the dynamic action of the warmth control can
be sooooo useful. Don't overdue this though, especially
Tranny may also actually seem to add midrange focus
because of the harmonic generation on the low and
low mid freqs. To smooth out solos, try the tracking
compressor with tranny and warmth. REMEMBER TO SET
UP COMPRESSOR FIRST! The warmth really interacts with
Plucked Instruments & Acoustic Guitar
- Plucked instruments can benefit greatly
from the Fatso's processing. Back in 1998, the Fatso
was taken to Greece and used on many very troublesome
ethnic plucked instruments. At Grammys, a club in
ATHENS, some bizarre FATSO behavior was immediately
noticed, when the extremely transient acoustic instruments
"swamped" several internal circuits. The compressor
needed a heavier knee with more "sponge" in the attack.
The tracking compressor (green and yellow LEDs on)
was tweaked first. The fast attack of the Tracking
Compressor can help get a "glassy" full sound since
the pick noise will be attenuated and the sustain
lengthened. Also the threshold of the warmth circuits
were lowered so they could grab the transient picked
edges easier. This allowed a solo instrument to be
louder without the sharp attack of each note hurting.
to FATSO Manual Index
you may want to keep the dynamic range of a plucked
instrument but need to smooth out just the hard front
edge of the attack. Warmth processing is perfect here.
Adjust the warmth until you have a smoother, more
natural sound - usually 3 - 10 dB of HF attenuation
is enough. In addition to your normal monitoring levels,
listen very softly, and very loudly to the adjusted
track to make sure it isn't too dull, or still in
need of "softening".
guitars can be so creamy. Many times you will have
an acoustic part that is very even and you can nicely
brighten it up with a top end eq (high frequencies).....
except for that one part where he really bangs it!
Use the Warmth control to grab those clangy brash
freqs. Usually 1 - 5 dB is enough but on really brittle
parts,10 - 15 dB on peaks may be ok on extreme peaks.
Again don't over due it, especially during tracking.
Listen really softly and really loudly to test evenness.
to FATSO Manual Index
Piano/Keys - Acoustic pianos often
need less attack & more sustain to fit into a
mix, but there are millions of exceptions. As far
as the compression part...Bruce Hornsbyish pianos
are often real or samples of real pianos with medium
attack and medium release, that achieve a "bite" followed
by sustained body. If you find the Buss type compressor
a bit gentle and too hot, and distorting some of the
peaks, try the Tracking Compressor with a fast release
etc. The GP type compressor may work depending on
how even the piano part is. If you have a dense mix
and really need to make it take up a finite spot in
the mix - go for the SPANK! This will slap the dynamic
range down smoothly and quickly. It won't be an unfamiliar
sound. Old Beatle records started using drastic amounts
of compression to keep a piano sitting inside a busy
arrangement. Some distortion can be "nasty" in a good
Grunge or saturator part of the Fatso will be very
useful also on piano and keys. Pianos and synths can
have quite a peaky transient and the instantaneous
nature of the saturator can often give you 6 db more
peak headroom before your ear detects clipping. Synthesizers
and samplers can benefit enormously since their envelope
generators often create huge front peaks. The Warmth
is also very useful here since it can soften the edges
and also take care of the sharp trebly plastic edge
without affecting the low frequency amplitude. Again
watch over using the Warmth - you will find subtle
use of the Fatso on keys to be extremely pleasing
once they are dropped back in the mix. Often you can
take a thin lifeless keyboard part and bring warmth
and reality to it.
Drums - Without any processing activated,
the saturator which is always inline, will pack those
peaks down smoothly giving you 3 - 6 dB more avg level.
Distortion indicator LEDs, the O VU and the Pinned
Red LED give you a good idea of what's going on. On
percussion, peaks can lite up the RED Pinned LED without
any nasty distortion, if they are short enough. Analog
tape can not handle all the top end and will round
out the sound... as will the FATSO's warmth processor
and saturator. Don't use more than 5 - 10 dB of warmth
on drums though.... or you are probably asking for
a dull sound! Try putting digitally recorded tambourines
etc through the Fatso and listen to the difference!
That clacky front edge will become warm and easy to
listen to - like the old analog tape and vinyl.
Snares/Kicks/Toms - If you don't
want to lose the basic sound, try setting the compressor
to buss compressor first. This is a very gentle slow
compressor that will leave the transients untouched.
If there are areas with over eq'd highs or unnatural
transients, get into the warmth processing. On snares
that have had 8 - 10K added and have some really overly
dynamic hits, 5 - 10 dB of warmth may fold the highs
back (attenuate them) and smooth out the tonality.
Use the High Frequency saturation that the warmth
control provides on Kick drums that have the occasional
clacky hit. The Tranny will be useful also. If the
Kick drum is too boomy or too thumpy without enough
clarity, the tranny will add some upper harmonics
to the low freqs, while rolling off some of the subsonics.
to FATSO Manual Index
Overhead Mics - Also for over dynamic
and brash cymbals, the warmth processing can be a
real sweetener. To soften the edge of cymbals try
Warmth on 4 or 5 setting and turn the input up to
control the amount of warmth. Watch anything over
5 dB of warmth as this is really attenuating a lot
of high end. But if it is just the front edge of the
cymbals, it can be verrrrrry pleasing! Of course compression
may be used but if it is, set it up first.
Room mics - Again, the most gentle
compressor for the room mics will be the BUSS compressor.
However, radical room compression is currently in
style! The Tracking compressor (Green and Yellow compressor
LED's lit) will be useful over a wide range from 1
dB of GR to 10 dB depending on what you are going
for, and what the tracks will allow. But for over
the top treatment, try SPANK! The SPANK is not the
NUKE of the Distressor yet it can add some of the
same sustain and intense size to it. The bargraph
can be run right offscale with the SPANK type compressor,
and still be a very useful sound. Fifteen to twenty
dB of compression is starting to have that John Bonham
thing that the Distressor can do. Watch over heating
the tracks though. Also, any loud cymbal playing will
become annoying with lots of compression on the room
mic. Sometimes it may help to feed a compressed room
signal back to the drummer while tracking to give
him a feel for balancing his cymbals and drums.
Distortion device - The Fatso has
very smooth clipping up until about 20%. Folks have
already used the Fatso as a distortion box with great
effectiveness and musicality. The warmth provides
another way to roll off some harsh distortion grit
as well, fattening up the lower harmonics. The Tranny
will drastically distort sub frequencies below around
50Hz, but it is adding the 2nd and 3rd harmonics that
sound very ballsy on those low tones. You may even
find that plugging a guitar and bass directly in can
work... although the impedance and gain structure
are more suited to line level, or a Direct box output.
Effects warmer - Try using the Fatso
as a tape delay simulator by putting it after a digital
delay. Turn the compression on BUSS compression and
the warmth on a little. Use the Tranny to roll off
subs and pump harmonics into the low frequencies.
Similarly, try the Fatso on a digital reverb to simulate
the plate reverb non-linearites and magnetic transducers.
It works great!!!!
to FATSO Manual Index
The Compressor and its Ratios
Each Fatso compressor or compressor "TYPE" as
we have termed it, sets the threshold, the ratio (in
the standard sense of the word) the attack, and decay.
This was done to provide an easy to set, yet versatile
group of curves. There are essentially 4 discrete
compressors with the fourth able to be combined with
the other three.
FATSO Manual Index
THE FOUR FATSO COMPRESSOR TYPES:
- very gentle 2:1 type ratio with Slow attack and
fast release. 1 - 4 dB of compression is usual for
this compressor type. Very soft knee; Five or more
dB of Buss compression is hitting it hard!
- General Purpose. A medium attack slow release type
that sounds pretty invisible while able to maintain
a consistent RMS level. The slow release will not
pull things into your face unnaturally.
- when both top LED's are lit, an 1176 type compressor
is enabled that is great for tracking instruments
and vocals during the recording process or during
- This is a radical limiter type compressor that was
specifically designed to emulate the nice squeeze
of the older SSL talkback compressors from the 70's
& 80's. Quite a bit higher fidelity though, as
you will notice.
By combining SPANK with any of the other 3 types of
compressors, one really has 7 compressor types (or
ratios), although the SPANK's aggressive nature will
tend to dominate when combined. The release curve
of all types is logarithmic, meaning it lets off quickly
at first and then slows. This release curve is a big
part of the FATSO's compressor sound.
Just what is a soft knee?
"soft knee" is a compression curve where the first
few dB of gain reduction occur at very low ratios,
gradually increasing as the signal increases (gets
louder). This makes the onset of compression very
hard to detect. The knee usually extends for a few
dB and gradually flattens out toward a final ratio.
All the Fatso compressor types have dominant knees.
The Buss Type Compressor has a knee that can be as
long as 15 dB, depending on the source.
to FATSO Manual Index
Vintage Compressor Emulation
the unit is based on the oldest compressor topology,
the unit can be made to sound similar to older classics.
The nonlinear nature of the older gain control elements
of opto-couplers, FET's, pentode (or triode) tube
bias or "mu" modulation, etc., can be closely emulated
if proper settings are used.
Opto-VCA tube models - To simulate the old light
controlled units (the LA2, LA3, LA4, DeMaria, Meek
units), try the GP (general purpose) compressor
with the Tranny on. Adjust input and outputs to
your taste. Remember our LED metering deflects much
faster than the old VU's so don't be afraid to hit
the unit quite hard (10-20 dB of compression on
peaks). This emulation is not as close as the Distressors
OPTO mode, however.
DBX160 2:1 (for over easy)
- Try the BUSS or GP Type Compressor, no Tranny.
LN1176 - Use the Tracking Type compressor
that lights both the green and yellow LED's in the
SSL type buss compression
- Use the Buss type Compressor. No Tranny.
SSL Talk back compressor
- Use SPANK!! Spank that mix, dang it!
Unlike the older units, the FATSO is uniform and predictable
from one unit to the next. Precise factory calibration
assures that if you go from one FATSO to the next,
these settings will all sound the same.
FOR HOME STEREO or AUDIOPHILE applications like CD
players, Ram Recorders etc. don't use any compression....
unless you really want to change the dynamics drastically.
Buss Type compression is going to be subtle but won't
keep your dynamics within a narrow range. The GP will
be useful for noisy parties or a noisy environment
where Low level music will be brought up closer to
the level of the loud parts. Verrrrrry useful on Beethoven's
3rd Symphony, I might add. LOL (laughing
out loud in Chat talk).
FOR MAKING TAPE COPIES LOUDER ETC. - Use the same
rules as above unless you want to really smash something
like radio stations do. In that case, try the Tracking
or even the SPANK type compressors. Otherwise, use
the Buss compressor for very gentle gain control,
or no compression.
to FATSO Manual Index
and Distortion Generator
old, sought after vintage gear is not anywhere near
as accurate (or linear) as devices made today, but
certain "faults" or non-linearities are exactly the
reason some sell today at 100 times their original
value. They color the sound with distortion and frequency
response shaping. Getting the frequency response flat
to 20kHz and having distortion below .5% used to be
an achievement. Today, in 2000AD, a 35 cent op amp
is flat to 3 MHz and produces distortion below .002%.
Getting things accurate in the digital age is relatively
cheap and easy, but getting a piece of gear to be
"musical" and fun to use is something else.
is well known that the triode distortion in tube circuits
produces lots of 2nd and 3rd harmonics, in somewhat
varying ratios. These lower order harmonics form "the
octave" and "the octave and a fifth" to the fundamental
musical tones. They are actually "musical" distortion.
Harmonics above the 2nd and 3rd get increasingly harsh
and unmusical, and therefore should be lower in amplitude
(<-60 dB) to keep with our line of thinking. Second
harmonic is considered to be the warmest and most
"consonant" harmonic distortion. The 3rd harmonic
is perceived more easily and often is the "BITE "that
is added to midrange and the "warmth" to the low freqs
by tube gear. Analog tape also saturates in this manner.
The 3rd harmonic is induced in the FATSO by increasing
level thru the distortion circuits. It is usually
the result of flattening the tops and bottoms of waveforms.
Second harmonic is also added especially while compressing
in the Fatso. 10% of second harmonic can sometimes
be hard to perceive.
have provided distortion indicator lights that indicate
some reference operating levels. A "0 VU" yellow LED
light indicates around 1% THD and the red "Pinned"
LED indicates 5% THD or more. These LED's are an excellent
guide to where the user is in the "Grunge Department"
and can help to avoid turning the music into an "overwell"
mess. You will find that the harmonic distortion is
generally more obvious on overall mixes and complex
programs. On individual instruments, sometimes 10%
distortion sounds "fat" and "analog" and isn't heard
as distortion at all.
to FATSO Manual Index
Warmth circuit is by far the most complex part of
the Fatso. Basically it is a very strange high frequency
(HF) gain control circuit or High Frequency limiter.
It operates very fast and should be very unobtrusive
in operation since it gets in and out of the way very
quickly. The desired result is akin to the HF saturation
that analog tape exhibits when the high frequency
amplitude interacts with the tape recorder bias to
produce self erasure of the certain frequencies. We
provide a very accurate display of the HF attenuation,
with the upper FATSO bargraph showing the gain reduction
at 20KHZ. The nature of the filter allows the corner
frequency to move as attenuation occurs.
provide just one control for the warmth but there
are other ways to control the overall action of this
circuit. If you do decide to use the compressor, set
it up first because it affects the operation of the
warmth. There is heavy interaction between the compressor
and warmth settings. The warmth control is a step
control with 8 ranges - no warmth action (no LEDs
lit), on up thru the highest setting of 7. Perhaps
the best way to think of the settings is as compressor
threshold, with 7 having the lowest threshold, and
the most warmth, responding quickly and often to high
frequency content. Just remember that instead of controlling
the overall level, this warmth "compressor" threshold
only affects the high frequencies.
of hours of experimentation were involved in developing
the filter, to make it capable of large gain reduction
at 20Khz without really dulling all the freqs (frequencies).
STILL ONE MUST BE CAREFUL NOT TO OVER DUE THE AMOUNT
OF WARMTH USED!!!! The temptation is to say "oh wow
that's great, so fat and warm, let's warm it more!"
DON'T GO THERE! Trust the meters when in doubt....
2 - 5 dB is quite a bit of warmth on most signals.
There may be times where 10 dB does the perfect job,
but trust us that if you see all the LED's light on
the warmth bargraph - you are being very naughty.
will find the warmth to be useful all by itself many
times without the compressor or Tranny or much saturation.
Originally the FATSO was only going to have the saturation
and this warmth circuit, but as our research went
on, we decided the extra circuitry of the Tranny and
compressor would provide some of the other important
nonlinear elements of tape compression, and "vintage"
gear as well.
Back to FATSO Manual Index
Tranny is short for transformer. In the old days,
to interconnect between audio components with low
impedance cabling (i.e. noise resistant), the audio
engineer used transformers on the input and outputs.
Transformers isolate two signals using wire coils
wound close to each other, but not actually touching.
They were never that linear and often introduced saturation
and LF distortion as well as changing the frequency
response. Transformer design and use was an art (hats
off to Rupert NEVE), and there were always tradeoffs.
However, it has been widely known that a good audio
transformer circuit can do wonderful things to an
audio signal. This was the goal of our TRANNY circuit.
We have tried to emulate the desirable characteristics
of the good old input/output transformers in a consistent
musical way, and in a selectable fashion.
of the older transformers had certain low frequency
characteristics that some of our newer and more linear
circuits and transformers have "overcome". As frequency
goes down, the audio signal gets more like DC (i.e.
slower moving). Transformers don't pass DC current
thru them, so strange things start happening as the
audio goes deeper. The addition of harmonics and peak
saturation along with frequency and phase changes
on the low frequencies occurs. We found that we could
capture the low frequency effects of large and now
expensive older output transformers in a weird, internally
buffered switchable design.
sum up the musical results of our Tranny circuit,
there will be a little more edge in the midrange,
and the super low frequencies will have been harmonically
altered in a way that allows them to sound louder,
even though the peaks are less than the original.
Playback on small speakers will show an improved audibility
of low end from the result of the psycho-acoustically-pleasing
distortion the Tranny adds. Something really interesting
we noticed... even though fundamentals below 100Hz
cannot show up on the little speakers... because of
the natural way a transformer saturates, the harmonics
give your ears enough clues that your mind somehow
fills in the fundamental. If you have the time, try
this experiment... put 40 Hz sine wave tone into the
Fatso, and match the Tranny level to the bypassed
level, then put the output thru a small speaker. A/B
the processed Tranny signal with the bypassed signal
in the small speaker. You will probably smile.....
to FATSO Manual Index
A note on Bypass and the Multiplexed Controls
Fatso uses a hardwired bypass relay enabling the user
to compare processed and unprocessed signals accurately.
When comparing the original signal from the processed
signal, matching the output level with bypassed signal
makes it very easy to hear the processing changes.
The bypass on the Fatso is multiplexed with the Tranny
control, so a double press is necessary while comparing
the processed signal to input signal.
To change compressor types, warmth ratio, and the
Tranny/bypass, press the associated button and cycle
through the options. These step function controls
are sometimes inconvenient when trying to compare
two settings, but if it was the only way we could
fit all the controls on a front panel without an LCD
display. It was very important to fit it all in the
single height, 1.75" cabinet. The color-encoded indicator
LED's were arranged in an easy to read pattern, with
Red LED's usually indicating radical or distorted
settings. The trade off of stepped controls vs. the
small size, and power of the Fatso seems well worth
Back to FATSO Manual Index
is straightforward. Connect AC line cord to 3 prong
jack, plug in XLR or phone plug ins and outs, and
you're wired. The phone and XLR input jacks are differential,
at the output, only the XLR is differential (balanced).
The output phone jack tip is wired to pin 2 of the
XLR out, and therefore is in phase with that pin.
The only possible problem is if you attach one of
the XLR output pins 2 or 3 to ground. A separate amplifier
drives each of these pins, so grounding one of them
will short the associated amplifier out. Therefore
if you only use pin 2 on your output cable, leave
pin 3 floating (unconnected) and vice-versa. The phone
jack ins and outs will be out of phase with pin 3
since the unit is wired pin 2 hot from the factory
(see note below). Pin 1 should almost always be grounded
on the XLR cables, but there are times where a buzz
can be introduced thru chassis grounds.
It is possible to change the wiring of the connectors
inside since they are hand wired. A user can therefore
make XLR pin two or three hot in relation to the phone
jacks. Always unplug unit before making any changes.
Our company cannot be responsible for damage to unit
or electric shock to anyone trying any modifications.
Back to FATSO Manual Index
Stereo Operation & 5.1
put the Fatso into Stereo mode, put a finger on one
warmth button while pressing the other warmth simultaneously.
The orange link LED will lite on both channels. Let
up on both buttons simultaneously. There are two main
link effects: 1) The compressors are linked and their
gain reduction will match, provided both are enabled.
2) The Channel 1 bypass control now controls both
channels Bypass/Tranny. It is usually best to match
all front panel settings on the two "left and right"
units to maintain imaging. However, unlike most units,
the user has the option to treat the left and right
channels differently. Sometimes for room mics,
keeping the units unlinked actually makes them sound
more stereo. This is due to unique left and right
ambient envelopes widening the stereo image.
5.1 surround where multiple units must be locked together,
chain one unit to the next with a short phone plug
cable in the "External Link" jacks, match controls,
and put units in "Link" mode. Two interchangeable
"External Link" jacks are provided to go to and from
each Fatso. The gain reduction will now match on all
units linked this way. For standard 5.1 processing,
three Fatsoes will be used.
compressor bargraphs on the bottom will indicate that
the two channels are responding together. Due to the
high resolution of the bargraph there may be slight
differences in the left/right bargraph response, mostly
on the first few LED's (i.e. 1dB, 2dB, 3dB of gain
You can alter the standard thresholds of the Fatso
by inserting a level control in the Insert point.
By turning the gain down there, the threshold will
move higher, elevating operating distortion. Adding
gain there will lower the threshold and lower Distortion.
It is also possible to sidechain process. Take the
"Link Out" of a unit, go to an EQ (and/or preamp),
then return it to the "Link In" of the same channel.
The sidechain must not have appreciable delay nor
be out of phase since it will affect the response
time and possibly comb filter the control signals
when in Stereo.
To set quick +4 tape levels, try setting output at
8 and "drive" input knob until compression occurs.
For ADAT's try 6 to 7 output level.
Remember you can combine different compressors with
SPANK Type compressor!
No sign of life - Check power cord for firm connection.
If still no life unplug unit and open top cover by
removing all top screws and check fuse toward rear
next to transformer. If it is blown, pry it out and
replace it with extra fuse provided in fuse holder
toward front of chassis. If fuse is OK, make sure
your Voltage select switch is set to current wall
outlet voltage (110, 220 VAC).
Unit keeps blowing fuses - Check internal voltage
select switch for proper settings (110/220). Otherwise,
suspect a short or power supply problem. Try to make
sure there is nothing trapped under the PC board,
shorting to the metal case. Attentive visual inspection
is still the most effective troubleshooting tool available.
Unit is on but not doing anything - The unit may be
bypassed or operating subtly. If bypassed, you need
to press the "BY-PASS" button so red LED goes off.
The input and output levels should always affect it
Bargraph shows gain reduction but very little or none
is actually occurring -The unit is possibly severely
out of adjustment. We use very stable trim pots and
high quality components, but it is possible that long
term component aging or failure may require factory
re-calibration. Also, dampness or something spilled
into the Fatso can cause this phenomenon. At present
you will have to return the FATSO to factory for re-calibration.
In the future there will be local dealers and/or service
centers to help.
Distorted output - If there is severe, un-musical
distortion, chances are you're hard clipping. Check
that the output cable is properly wired and any unused
output pins (2 or 3) on XLR are floating (left unconnected).
Shorting an output pin will not harm the unit but
can show up as distortion in the output driver. The
distortion this unit is meant to impart is harmonic
and should not sound like crackly distortion caused
by hard clipping. If the pinned LED stays on, you
must turn down the input!
No output level - Make sure there is audio getting
to the unit, and that the input and output levels
are turned up.
Unit pops or unnaturally pumps with low frequencies
Try a different compressor TYPE.
Unit seems noisy - The dynamic range of the FATSO
is greater than CD (16 bit) quality. However, if you
are compressing a noisy signal, the noise is pushed
up along with the soft signals. If you have 20 dB
of gain reduction on a room mic that has a 90 dB S/N,
the noise floor will be raised 20 dB in quiet areas,
bringing the noise floor up to 70 dB. Since the FATSO
is capable of lots of compression without sounding
unnatural, you can often bring hiss levels up undesirably.
Remember your current input level, and then ensure
that the noise is coming from outside the unit by
turning the input knob off (to 0). All noise should
disappear. Try gating before compressing.
Unit forgets where it was when power was shut off
- Non Volatile memory cap has become defective, or
possibly some other type of logic failure has occurred.
Contact the factory for servicing.
to FATSO Manual Index
Changing the fuse
Always unplug unit before removing cover!
Pull out the power plug from the AC outlet, open unit,
and ensure fuse closest to rear of the unit is blown.
(Note: The fuse closer to the front panel is a spare
fuse and is not connected to anything). Gently pry
out one end of the fuse and then the other, replacing
it with extra fuse provided near battery holder in
front of unit. A small screwdriver may be helpful.
Before putting cover on, plug in unit, keeping hands
out of the box, ensure that the fuse doesn't blow
again, indicating a possibly more serious problem
(see troubleshooting). If OK, unplug unit, screw down
top cover and return the unit to normal use. Any fuse
from .3 to .6A should be safe, but .3A (1/3A) is what
is specified and used at factory. Replace spare fuse
in front if available. We went to the expense to keep
an extra fuse inside... you should too.
Line Voltage Select
the voltage for 220 or 110 operation also involves
unplugging the unit and removing top cover. Inside
on the right (as the front of the unit faces you),
is a switch with 110 or 220V showing on its face.
Select the desired voltage by sliding the switch until
it indicates that voltage and you're done. Replace
cover and screws.
Back to FATSO Manual Index
Warranty and Factory Service
Empirical Labs Inc. product is covered by a limited
warranty covering full parts and labor for 3 years
from the purchase date. The warranty is only effective
if the owner has returned his or her warranty card.
See warranty card for further details.
problems arise, call your dealer or distributor to
determine the state of your warranty and if it becomes
necessary, pack the unit up well1, with a note explaining
the problem and return to Empirical Labs for repair.
Include your name, address, phone, and the date of
purchase. Send the unit with freight prepaid to the
address below and mark it Attn.: Service.
we can be reached on the Web at www.empiricallabs.com
Pack the unit in original carton if possible. Otherwise,
pack with bubble pack and /or foam in a thick corrugated
box. Shipping people are absolutely brutal to large
packages and you must take every precaution against
constant dropping, throwing, and crushing. We are
not liable for products damaged during shipping.
Empirical Labs Products:
DISTRESSOR EL8 - Classic
Knee Compressor. Found on thousands of major records!
Lab for Eventide DSP4000 - Complete mastering facilities
in a double height rack mount unit! Call Eventide
for information. (See phone number below)
Three dimensional software for the Eventide DSP4000
and H3000. Contact Eventide at www.Eventide.Com
are several elements inside the FATSO which were designed
to be "modifiable". Although we cannot guarantee it
at this time, Empirical Labs may release information
and hardware options that will allow owners to alter
the curves and other important performance parameters
of their FATSO. Most of these modifiable elements
will probably not improve the performance, but will
offer other very cool signal processing variations.
It may be possible for user to safely modify the FATSO
and create unique sets of curves and filter options.
If you have sent in a properly filled out warranty
card, we will keep you apprised of these developments.
Do not attempt to modify or make adjustments to your
FATSO until you have notified Empirical Labs and been
sent the necessary information. There are a number
of critical adjustments that cannot be made properly
without the calibration tools we have here at the
factory. Any sign of internal adjustment by the user
will void your warranty with the exception of changing
the fuses or line voltage selection. Empirical Labs
Inc. takes no responsibility for the safety of anyone
opening the FATSO for any reason. There are dangerous
voltages present when unit is plugged in. Refer unit
to properly qualified service center or return to
to FATSO Manual Index
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