elysia alpha compressor User Manual

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The information in this document is subject to

change without further notice and shall not be

deemed as an obligation or warranty of any kind by

the manufacturer. No warranties, express or implied,

are made with regard to the quality, suitability or ac-

curacy of this document.

The manufacturer reserves the right to change the

contents of this document and/or the associated

products at any time without the provision of prior

notice. The manufacturer shall not be held liable for

damages of any kind arising from the use, or the in-

ability to use this product or its documentation.

The information in this document is subject to copy-

right. All rights, technical changes and errata are re-

served. No part of this manual may be reproduced or

transmitted in any form or for any purpose without

the explicitly written permission of the copyright

holders.

elysia is a registered trademarks of elysia GmbH.

Other product and brand names contained in this

document are used for identication purposes only.

All registered trademarks, product designations or

brand names used in this document are the property

of their respective owners.

This product is manufactured accord-

ing to the 2002/95/EC directive. The pur-

pose of this directive of the European Union is the Re-

striction of Hazardous Substances (RoHS) in electron-

ic equipment in order to protect health and nature.

© 2006 elysia GmbH

2

WARNING: High Voltage

• Risk of electric shock.

• Do not open chassis.

• Refer service to qualied service sta only.

• Before connecting the device to the main power supply, check if the right

voltage is selected.

• Replace fuse with the same type and value only.

• This device must be connected to ground.

• Do not use a damaged power cord.

• Never place containers with liquid, e.g. beverages or a vase, on the unit.

• Do not expose this device to rain or moisture.

• Do not use this device near water, e.g. swimming pool, bathtub or wet base-

ment.

CAUTION: Temperature

• Surfaces of the device may become hot during operation.

• Do not install this device near any heat source such as radiators, stoves or

other heat sources.

• Always allow enough ventilation space around the unit for air circulation.

• Do not cover circulation vents.

CAUTION: Connecting & Mounting

• Never connect the output of a power amplier to this device.

• Place the unit on a rigid board or x it to an appropriate rack.

• Use the device according to this manual only.

CAUTION: Humidity

• If this device is moved from a cold place to a warm room, condensation can

occur inside the device. To avoid damaging the unit please allow it to reach

room temperature before switching on.

CE Conformity

elysia GmbH, Am Panneschopp 18, 41334 Nettetal, Germany, declares with sole

responsibility that this product complies with the following norms and directives:

• 2006/95/EG Low Voltage Directive (formerly 73/23/EWG or 93/68/EWG)

• 89/336/EWG EMC (Electromagnetic Compatibility) Directive

• DIN EN 55103-1 EMC of audio equipment - Emission

• DIN EN 55103-2 EMC of audio equipment - Immunity

This declaration becomes invalid by any unapproved modication of the device.

Nettetal, 01.06.2006 - Ruben Tilgner & Dominik Klaßen

3

Dear friend of audio culture,

First of all, we would like to thank you sincerely for choosing the alpha compressor as your new

mastering tool. From now on, you not only have the maximum possible audio quality in dynamics

processing at your disposal, but also a complete arsenal of exible and eective tools which will

shift the fruit of your work to a new level.

In short: You have opted for a product designed without the slightest compromise!

Please take a little time to read this manual thoroughly, as it will help you to entirely understand

the enormous potentials and to really push the envelope. We have attached great importance to

practical experience and fast results, which is also the reason for reserving the explanation of the

technological excesses realized in the alpha compressor to our website.

The Basics chapter contains essential information for the fundamental comprehension and quick

use of the specic functions and modules. After this, a couple of Scenarios are introduced in order

to illuminate just some of the versatile applications of your new favorite compressor. If you want

to go into further details, please have a look at the Reference chapter which elaborates on every

particular parameter.

If you have further questions or comments, please do not hesitate to contact us – we enjoy being

of your service. But for now, it is time to wish you lots of fun and pure audio pleasure with your

alpha compressor.

Use the Force…

the elysians

4

BASICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Signal Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Link Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Stereo Compression. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Auto Fast. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Feed Forward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Transformer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

M/S Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Sidechain Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Audio Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Mix Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Soft Clip Limiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

SCENARIOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Stereo Linked . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

M/S Linked. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

M/S Unlinked . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Upward Leveling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

M/S Leveling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Groove Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Vocal Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

DeEssing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Parallel Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Stereo Enhancer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

LoFi Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Extreme Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

REFERENCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Threshold Oset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Attack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Auto Fast Attack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Auto Fast Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Ratio Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Ratio Feed Forward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

EQ Gain Low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

EQ Gain High . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

EQ Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

SC Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

SC Low Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

SC High Pass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Mix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Soft Clip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Level Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Recall Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

INDEX

5

Mix

Gain

EQ Freq

SC Gain

dB

EQ Gain

Auto Fast

Feed ForwardOnAuto Fast

x10

On

Transformer

Direct

Compressed

On

Thresh

AttackmsReleasemsRatio

1:X

Soft Clip

SC Freq

BASICS

Controls

Both channels of the alpha compressor are absolutely identical regarding their electronic design.
Therefore both sides of the front panel have exactly the same controls and switches. Continuative
information on the specic functions can be found on the pages in brackets.

Thresh Attack Release Ratio

EQ Freq

On

Mix Gain

Hz

Auto Fast

x10 On

Auto FastFeed Forward

SC GaindBSC FreqEQ Gain

Soft Clip

TransformerDirect Compressed On

Soft Clip

Gain Reduction

M/S Mode Active Channel Link

Threshold: the operating point of the compressor. If the input level exceeds the value set
with this controller, the compression process will start. (p. 26)

Feed Forward: switches the junction of the sidechain alternatively behind (feedback) or in
front (feed forward) of the actual compressor section. (p. 14)

Attack: the transient response of the compressor. It determines the time the alpha compres­sor needs to reach 10 dB of gain reduction. (p. 27)

Auto Fast: a semi-automation. This function shortens the attack time automatically on fast
and loud signal impulses. (pp. 13, 27)

Release: the return phase of the compressor. It controls the period of time between when
the input signal falls below the threshold and the compressor’s return to unity gain. (p. 28)

Auto Fast: similar to the Auto Fast feature for the attack parameter, this function automati­cally shortens the release time and then returns to the set value. (pp. 13, 28)

Ratio: the relation between the input level and the output level. In feed forward mode, the
actual ratios become signicantly higher than the printed values. (p. 29)

Gain Reduction: the display for the gain reduction. Shows the amount of compression mea­sured in dB as an optical support for the acoustic events. (p. 12)

Soft Clip LED: indicates the activity of the Soft Clip Limiter. This LED should only light up
shortly from time to time in order to avoid audible distortion. (p. 19)

EQ Gain: the characteristic of the Niveau Filter. Between the mid and fully counter-clockwise
position, bass is boosted and treble is cut (vice versa in the other direction). (pp. 17, 30)

BASICS – Controls

6

EQ On: activates the Niveau Filter. In the signal path, this special EQ is placed after the com-

pressor section, thus it will not inuence this section’s behavior. (p. 17)

EQ Freq: the center frequency of the Niveau Filter. Around this reference point, bass is boost­ed and treble is cut or vice versa. (pp. 17, 31)

x10: shifts the frequency range of the Niveau Filter. The printed values from 20 Hz to 2.0 kHz
are multiplied by 10 to 200 Hz and 20 kHz. (pp. 17, 31)

SC Gain: inuences the character of the sidechain lter. It can be blended from high pass to
low pass with lots of expedient interim values. (pp. 16, 31)

SC On: activates the sidechain lter which allows frequency-dependent shaping of the com­pression process. (p. 16)

SC Freq: sets the highest/lowest frequency which – dependent of the SC Gain controller –
you want the compressor to react to/not to react to. (pp. 16, 32)

Direct: makes the direct signal routed directly from the input stage audible in its respective
channel or mutes it when inactive. (p. 18)

Mix: if both the Direct and Compressed knobs are active in their respective channel, the Mix
controller blends between them for onboard parallel compression. (p. 18, 33)

Compressed: makes the compressed and/or ltered signal audible in its respective channel
or mutes it when inactive. (p.18)

Gain: compensates for the level reduction caused by the compression process. The control­ler oers up to 12 dB of amplication. (p. 9)

Transformer: switches an additional transformer into the signal path as an additional means
of sound shaping. (p. 14)

Soft Clip: helps to limit short, loud transients to subsequent A/D converters from clipping by
rounding the signal peaks. (pp. 19, 33)

Soft Clip On: activates the Soft Clip limiter. The limiter modules for both channels should
always be activated or deactivated at the same time. (p. 19)

M/S Mode: enables to process the middle and the side signals separately, and nally de­codes both channels back to left and right/stereo. (p. 15)

Active: enables the processing modules of the alpha compressor. In deactivated state, the
input is directly routed to the output by a hardwire bypass. (p. 10)

Channel Link: both channels can be operated in combination with the left control panel as
master. Note: Filter, mix, gain and limiter stages will not be linked in this mode. (p. 11)

BASICS – Controls

7

BASICS

Connectors

Voltage
220 - 240 VAC ~ 50 Hz
110 - 120 VAC ~ 60 Hz

Power Consumption 100 W

Made in Germany

WARNING!

RISK OF ELECTRIC SHOCK - DO NOT OPEN!

Fuse Type

1.5 A Slo-Blo @ 220 - 240 VAC

3.0 A Slo-Blo @ 110 - 120 VAC
elysia GmbH • D-41334 Nettetal • Germany

Mains module

This module combines the line cord connector, the on/o switch, the fuse holder with in­tegrated 230/115 VAC voltage selector and a line lter for providing the transformer with
clean current. Note: Some export version have a xed voltage of e.g. 100 or 115 VAC and
cannot operate at 230 VAC.

Controller Brightness Button Brightness

Gnd1Hot

2

3

Gnd

Right Out Right In Left InLeft Out

Hot2Gnd

Cold

1

3

Gnd1Hot

2

3

Gnd

Hot2Gnd

1

3

Cold

WARNING: High voltage

Make sure to disconnect the line cord before replacing eventually blown fuses or changing
the operating voltage of the unit!

In order to change the operating voltage, the fuse holder has to be taken out and re-in­serted so that the desired voltage can be read correctly (and is not standing upside down).
The white triangular arrow that belongs to the chosen voltage setting points at the small
rectangular mark on the mains module.

WARNING: Fuses
Always make sure to use the correct fuses for the chosen voltage: 230 VAC 1.5 A Slo-Blo or
115 VAC 3.0 A Slo-Blo. Incorrect or missing fuses are dangerous safety hazards for both the

unit and yourself!

Audio outputs (+4 dBu)

Pin assignment balanced: 1 ground 2 hot (+) 3 ground
Pin assignment unbalanced: 1 ground 2 hot (+) 3 idle

Audio inputs (+4 dBu)

Pin assignment balanced: 1 ground 2 hot (+) 3 cold (-)
Pin assignment unbalanced: 1 ground 2 hot (+) 3 ground

Note: If a device that is placed before the alpha compressor in the signal chain has an un­balanced output stage, a complete muting can eventually occur when the compressor is
activated. If this happens, please follow the advice on page 34.

LED brightness dimmers

Controller brightness: light intensity of blue LEDs
Button brightness: light intensity of white LEDs + logo disc

BASICS – Connnectors

8

Getting Started

Never fear! With its many options and quite a lot of controllers the alpha compressor might look a

little tricky at rst sight. In practical experience, however, it is a clearly structured and easy to use

tool.

The control elements are divided into three layers, whereas the left and the right channel sides are

completely identical.

Thresh

+11

+15

+18

+4

0

-3

-6

-9

-12

+20

-13

dB

Attack

13

7.0

2.0

24

28

50

70

110

130

0.01

150

ms

Release

150

100

75

300

430

570

1k5

60

1k8

ms

Ratio

800

1.4

1k1

1.3

1.2

Auto FastFeed Forward Auto Fast

1.7

1.6

1.8

1.9

2.1

2.2

1.1

2.4

1:X

Compressor section

The upper array contains the dynamic section with the classic parameters threshold, attack, re-

lease and ratio. Furthermore, there are some interesting special functions like feed forward and

Auto Fast that will be explained later.

0.3

0.3

1.0

1.6

2.2

2.7

Lo

EQ Gain

1.6

2.2

2.7

Hi

dB

On x10 On

EQ Freq

40

30

22

20

140 170

Hz

-0.3 -0.3

220

300

500

1k0

2k0

-1

-2

-5

-12

LP

SC Gain

-2

-5

-12

HP

dB

SC Freq

80

50

40

30

280 340

Hz

430

580

900

2k0

3k3

Filter section

Firstly, the middle array features the audio lter, which enables you to perform subtle changes

on the overall tonal character. Secondly, it consists of the sidechain lter which allows frequency-

dependent compression when it is switched into the detector path.

50

Mix

30

20

10

60

70

80

90

100

Dir

Com

%

2.0

1.5

Gain

0.5

3.5

4.5

0

12

dB

Soft Clip

6.0

8.0

10

11

TransformerDirect Compressed On

16

14

11

19

21

24

25

dB

8.0

5.5

4.0

3.0

Level section

The lower array starts with the mix controller that allows blending between the unprocessed and

the compressed, ltered and amplied signals. Next in line is the gain controller for making up the

gain of the reduced signal. Last comes the Soft Clip limiter which allows catching fast transients.

BASICS – Getting Started

9

BASICS

In the middle of the unit, right below the gain reduction meters, there are three buttons to set the

distinct operating modes of the alpha compressor:

M/S Mode Active Channel Link

M/S Mode

If this button is pressed, the alpha compressor will work in M/S mode in which the controls on the

left side aect the middle channel and those on the right side belong to the side channel. Other-

wise the unit will work in stereo mode.

Active

If this button is pressed (LED glows), the incoming signals will be processed by the alpha compres-

sor. Otherwise there is a hard bypass, whereas the gain reduction meters will still stay active.

Channel Link

If this button is pressed, the left upper array will act as a master for the dynamic sections of both

channels. All other parameters (lter, mix, gain, limiter) are not linked, though, and therefore have

to be set manually. In this mode the gain reduction is identical for both channels.

Signal Flowchart

The schematic shows the signal ow from the input through the specic modules to the output.

M/S matrix, sidechain lters, audio lters, mix stages, transformers and Soft Clip limiters can be

optionally switched into the signal path via relays, which is also true of the Auto Fast and feed

forward functions.

Left

Input

Input

Transformer

Input

Buer

Sidechain

Filter

Sidechain

Compressor

Gainreduction

Meter

Audio

Filter

Transformer

Mix

Stage

Gain

Stage

Soft Clip

Limiter

Output

Amp

Left

Output

10

Input

Buer

Input

Transformer

Right
Input

M/S Encoder

Compressor

Sidechain

Sidechain

Filter

Audio

Filter

Gainreduction

Meter

Gain

Stage

Mix

Stage

Transformer

M/S Decoder

Right

Output

Output

Amp

Soft Clip

Limiter

BASICS – Signal Flowchart

Thresh Attack Release Ratio

Auto Fast

Feed ForwardOnAuto Fast

Thresh

AttackmsReleasemsRatio

1:X

Soft Clip

EQ Freq

On

Mix Gain

Hz

Auto Fast

x10 On

Auto FastFeed Forward

SC GaindBSC FreqEQ Gain

Soft Clip

TransformerDirect Compressed On

Gain Reduction

M/S Mode Active Channel Link

EQ Freq SC Gain

EQ Gain

Mix

x10 On

Gain

SC Freq

dB

Soft Clip

TransformerDirect Compressed On

Link Mode

In link mode, both channels of the alpha compressor can be coupled and operated with the con-

trollers and switches of the left control panel. Please consider the following important notes:

Both sides of the alpha compressor utilize exactly identical electronic modules that could even be

interchanged with each other in principle. This grants a high equality of signal processing in the

left and right channel, which is especially important in stereo mode. Another result is the excellent

isolation of both channels from each other, and the audio quality will not decline because there

are no lossy to and fro signal routings in the circuitry.

As an eect of this design approach, only the control functions of the compressor (marked green

in the gure) are combined in link mode. The left control panel becomes the master, that is the

settings for the left channel are transferred to the right channel – therefore the settings of the

particular controllers on the right side are not relevant in link mode.

At the same time this means that the audio functions of the compressor (marked orange) are not

combined. In linked stereo mode please pay attention to set the controllers and switches for both

EQ, mix and gain sections identically. Otherwise an audible drift between the left and the right

channel might occur.

In linked M/S mode, however, you can set the EQ, mix and gain stages to dierent values to achieve

certain eects. For example, you can use dissimilar settings of the gain controllers to alter the ste-

reo width (more information on page 24) or you can employ the EQ stages for mid and side signals

separately.

In the signal path, the Soft Clip limiters are located after the M/S decoder. This means that the lim-

iters are completely independent from the operation mode of the alpha compressor – they always

work in stereo. The limiters are also not aected by the status of the link function and therefore

have to be set at the same values every time they are engaged.

BASICS – Link Mode

11

M/S Mode

Mix

EQ FreqHzSC Gain

dB

SC Freq

EQ Gain

Feed Forward

On

x10

On

Transformer

Direct

On

Soft Clip

Mix

EQ Freq

SC Gain

dB

EQ Gain

Auto Fast

Feed ForwardOnAuto Fast

x10

On

Transformer

Direct

On

Thresh

AttackmsReleasemsRatio

1:X

Soft Clip

SC Freq

BASICS

Thresh Attack Release Ratio

Auto Fast

Gain

Compressed

Auto Fast

Soft Clip

Gain Reduction

Active Channel Link

Gain

Compressed

Stereo Compression

In order to get a rst impression of the sonic qualities and the control characteristics of the alpha

compressor, only the controllers highlighted in the gure are used. The functions that are cur-

rently not needed should be deactivated (related LEDs do not glow). Et voilà: We have a classic

linked stereo compressor!

A track with a broad dynamic range is the best material for a rst test. Just start playing with the

threshold, attack, release and ratio parameters of the left channel in order to get to know the con-

trol behavior of the compressor. Allow yourself to take some time for this, as the understanding of

the basic control characteristics is the most important condition for perfect results.

Keep having a look at the gain reduction meters from time to time. No doubt: the ear is the de-

cisive benchmark. Just consider the optical information as a supporting means to evaluate the

compression process (fast/slow, strong/weak, etc.).

The levels of the compressed signals can be made up by adding an appropriate amount of ampli-

cation with the gain controllers. Since the link function will only aect the control voltage of the

compressor, the gain controllers of both channels should be set to the same values in stereo link

mode. For instant A/B comparisons just push the active button.

Note: If the threshold controller produces too little gain reduction when turned hard right or too

much of it when turned hard left, please go to page 26 and see how to adjust the internal thresh-

old.

Left

Input

Compressor

Gain

Stage

Left

Output

BASICS – Stereo Compression

12

Right
Input

Compressor

Sidechain

Gain

Stage

Right

Output