LOOPTROTTERAUDIO ENGINEERING

OWNER'S MANUAL

FET COMPRESSORwith TUBE SATURATION

Manual by: Rafał Smoleń

Table Of Contents1. Introduction2. Installation3. Signal Path4. Controls - Front Panel

5. Connectors - Rear Panel

6. Getting Started

Introduction

Thank you for choosing Looptrotter MONSTER. This two channel single band FET

compressor provides unique functionality for individual instruments or sections

(submixes for drums, guitars, keys). It can also be utilized on summing bus and

in mastering.

MONSTER consists of three devices of an original design in one piece:

FET compressor / limiter, tube saturator and fully transparent wet/dry signal mixer.

FET transistor is responsible for gain reduction and is optimized for adding

low order harmonics. In its non-linear characteristics it reminds the electron tubes,

so even with the deep compression the sound focused and detailed.

The saturation circuit is built with military grade electron tubes with

a prolonged longevity (NOS). The unique feature of Monster Compressor is the option

of boosting the even harmonics added by the tubes (2nd BOOST), especially useful for

extreme processing of tracks and subgroups.

The MIX option is based on integrated circuits dedicated to sound processing. It is

intended to sound transparent, but gives perfect functionality when using MONSTER as

an insert device when 100% processing is unwanted.

Monster Compressor is a device with "analog character". It was designed to

either complement super clean digital technology or expand sonic possibilities in

your analog studio. The compression module treats the signal in a very musical way,

before the tube saturation. And the unique combination of compression and tube

saturation makes the sound seem distinctly closer, every detail stand out and gives

the energy to the processed sound. It makes the sound more tactile and ear friendly.

MONSTER is a precise device, in terms of control and operation. All rotary

switches (except saturation stage knob) are stepped, so it's easy to record and recall

settings and allows you to maintain the same exact settings for both channels.

Installation

Looptrotter MONSTER is factory set to the correct mains voltage for your country. Please check the voltage setting on the rear panel.

With the power button switched off, connect the IEC mains cable to a 50/60 Hz AC source of the voltage typical for your country.

Connect the signals to the 3 pin XLR slots on the rear panel:

LOOPTROTTERAUDIO ENGINEERING

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LOOPTROTTERAUDIO ENGINEERING

Signal Path

The FET Compressor Stage:

ATTACK

RELEASE

0

1

2

3

45

6

7

8

9

10

OUTPUTINPUT

FET COMPRESSOR

COMP.

LIMITER

BYPASS

PROCESS

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7

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100ms

ATTACK

RELEASE

0

1

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45

6

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8

9

10

OUTPUTINPUT

FET COMPRESSOR

COMP.

LIMITER

BYPASS

PROCESS

0

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45

6

7

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.2

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100ms

S I D E C H A I NF I L T E R S

T I M I N GC I R C U I T

V O L T A G E - C O N T R O L L E DR E S I S T O R A T T E N U A T O R

A M P L I F I E R

OTHER CH.

ATTACK

RELEASE

OUTPUT

INPUT

L I N K

DUAL

COMP.

LIMITERS I D E C H A I N

O U T P U TI N P U T

The FET compressor is fed by INPUT knob. There is no threshold or ratio setting,

so the more signal gets into the compressor, the more gain reduction occurs. However,

there are traditional attack / release setting knobs, allowing you to set fast to slow

attack time (0.1 ms - 100 ms), and release time between 15ms to 1.5 sec. This is useful

to shape the compressor's behavior and allows to use for example fast attack/release

times for drums, and slower settings for vocals.

The compressor / limiter switch gives you the choice of compression curve.

The compressor's curve has softer knee, while the limiter's knee is harder

(see diagram)

INPUT

OU

TP

UT

20

20

LIMITER / COMPRESSOR

040 35 51030 25 15

0

40

5

35

10

30

15

25

INPUT

OU

TP

UT

20

20

LIMITER / COMPRESSOR

040 35 51030 25 15

0

40

5

35

10

30

15

25

The bypass switch makes the signal avoid the compressor section completely.

Output knob controls compressor's output level.

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Tube Saturation stage:

TUBE

2nd

SATURATION

BYPASS

PROCESS

BOOST

0

1

2

3

45

6

7

8

9

10

TUBE

This is where the magic happens. The more signal gets into the tube saturation

stage, the more saturation occurs. Please note that it also depends on the output

level of the compressor's stage, so it gives you the option to get even more extreme

saturation when raising the compressor's output level. The saturation knob indicates

numbers from 0 (the smallest amount of saturation but still tube processing

occurs!)to 10. To achieve more saturation, the 2nd BOOST switch brings up even

harmonics introduced by the tube circuit. The process / bypass switch allows the

signal to bypass tube circuit completely.

Mix and Output Stage:

0

10

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100

MAIN

5

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10

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5

MIX OUTPUT

dB% - +0

10

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MAIN

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5

MIX OUTPUT

dB% - +

This section allows you to mix completely dry signal from the input of the device with processed signal (compressed and/or tube saturated) with the use

of one mix knob. The numbers indicates the percentage amount of wet signal, so 0% means

that on the output of MONSTER compressor is completely dry (unprocessed) signal, 50%

means that there is equal amount of dry and processed signal, and 100% means

that there is fully processed signal on the output of the device.

The Output knob allows you to tweak the output level of the MONSTER compressor.

The range is from -5 to +5 dB.

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Controls –Front Panel:

Beside the controls described in the section above there are few more

elements in the central section of the front panel.

POWER – switches the device on or off

LINK/DUAL – when the LINK is on, the compressor's control voltage is summed up and

common for both channels but all other settings for compressor's input, output,

attack release, tube saturation knob and switches are independent. So if you want

to use MONSTER compressor as the stereo unit you MUST set all knobs and switches to

same exact settings.

When DUAL switch is on, both left and right channels of the compressor are fed by their

own independent sidechain signal.

Ch 1/2 PROCESS / TRUE BYPASS – switches MONSTER's channels into fully operational

circuit or completely bypasses the unit's circuits (the input signal is led directly

to it's output)

Connectors – Rear Panel:

1

3

21

3

2 1

3

21

3

2

Channels 1 and 2 has input and output connectors based on XLR sockets. There are

additional TRS unbalanced outputs for each channel marked as Monitor Output.

Sidechain Input and Output:

This circuit allows you to master-shape the compressor's sidechain signal. It can be

used as an insert send/return to EQ the sidechain and obtain specific kind

of compressor's behaviour, eg. boost of 8-10kHz on the external EQ and setting

the compressor's attack/release to it's fastest settings will make the compressor

act as a deesser.

Sidechain input can also be used to feed the compressor with external analogue signal,

eg. using kick drum as the external sidechain signal while the compressor inserted

on the main mix buss will make the compressor „pump-up” the whole mix.

XLR:PIN 1: groundPIN 2: positivePIN 3: negative

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Getting Started:

As a starting point for general purpose, set compressor's input and output to

5, attack 15 and release to 50. Set mix knob to 100% and Main Output to 0.

Increase compressor's input and listen how gain reduction works with

your signal. When you decide your signal is well cooked, start decreasing

the Mix amount and listen how processed signal blends with the dry signal.

Try changing attack and release of the compressor. As soon as you're done

with experimenting with the compressor itself, engage the tube saturation

circuit and check how it works with the processing you've already achieved.

The most natural warmth and tube-style distortion can be obtained with

Saturation at 4 and 2dBoost switch to off.

More overdrive may be obtained by switching the 2d Boost and turning the

saturation knob over 6. Adding very fast attack and release time and

switching compressor to limit mode gives more harshness from both

compressor and tube saturator.

For optimum results make sure the source signal is not clipped before it

arrives at the MONSTER's input.

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