thomann S-75, S-150, S-100 User Manual

S-75 • S-100 • S-150

power amplifier

user manual

Musikhaus Thomann e.K.
Treppendorf 30
96138 Burgebrach
Germany
Telephone: [phone]

E-mail: [e-mail]
Internet: www.thomann.de

07.03.2014, ID: 141140_144356_141141

Table of contents

1 General notes............................................................................................................................................... 4

2 Safety instructions..................................................................................................................................... 7

3 Features....................................................................................................................................................... 12

4 Connections and controls................................................................................................................... 13

5 Installation and starting up................................................................................................................ 21

5.1 Tips on handling speakers............................................................................................................ 24

5.2 More useful tips................................................................................................................................ 25

6 Technical specifications....................................................................................................................... 27

7 Plug and connection assignment.................................................................................................... 29

8 Cleaning....................................................................................................................................................... 35

9 Protecting the environment.............................................................................................................. 36

Table of contents

S-75 • S-100 • S-150

3

1 General notes

This user manual contains important information on safe operation of the device. Read and
follow all safety notes and all instructions. Save this manual for future reference. Make sure
that it is available to all persons using this device. If you sell the device, include the manual for
the next owner.

Our products are subject to a process of continuous development. We therefore reserve the
right to make changes without notice.

This section provides an overview of the symbols and signal words used in this user manual.Symbols and signal words

General notes

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Signal word Meaning
DANGER! This combination of symbol and signal word

indicates an immediate dangerous situation
that will result in death or serious injury if it is
not avoided.

CAUTION! This combination of symbol and signal word

indicates a possible dangerous situation that
can result in minor injury if it is not avoided.

NOTICE! This combination of symbol and signal word

indicates a possible dangerous situation that
can result in material and environmental
damage if it is not avoided.

Warning signs Type of danger

Warning – high-voltage.

General notes

S-75 • S-100 • S-150

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Warning signs Type of danger

Warning – danger zone.

General notes

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2 Safety instructions

This device amplifies electric audio frequency signals to operate passive speakers. Use the
device only as described in this user manual. Any other use or use under other operating con‐
ditions is considered to be improper and may result in personal injury or property damage. No
liability will be assumed for damages resulting from improper use.

This device may be used only by persons with sufficient physical, sensorial, and intellectual
abilities and having corresponding knowledge and experience. Other persons may use this
device only if they are supervised or instructed by a person who is responsible for their safety.

DANGER!
Danger for children

Ensure that plastic bags, packaging, etc. are disposed of properly and are not
within reach of babies and young children. Choking hazard!

Ensure that children do not detach any small parts (e.g. knobs or the like) from
the unit. They could swallow the pieces and choke!

Never let children unattended use electrical devices.

Intended use

Safety

Safety instructions

S-75 • S-100 • S-150

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DANGER!
Electric shock caused by high voltages inside

Within the device there are areas where high voltages may be present. Never
remove any covers.

There are no user-serviceable parts inside.

DANGER!
Electric shock caused by short-circuit

Always use proper ready-made insulated mains cabling (power cord) with a pro‐
tective contact plug. Do not modify the mains cable or the plug. Failure to do so
could result in electric shock/death or fire. If in doubt, seek advice from a regis‐
tered electrician.

Safety instructions

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CAUTION!
Possible hearing damage

With loudspeakers or headphones connected, the device can produce volume
levels that may cause temporary or permanent hearing impairment.

Do not operate the device permanently at a high volume level. Decrease the
volume level immediately if you experience ringing in your ears or hearing
impairment.

NOTICE!
Risk of fire

Do not cover the device nor any ventilation slots. Do not place the device near
any direct heat source. Keep the device away from naked flames.

Safety instructions

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NOTICE!
Operating conditions

This device has been designed for indoor use only. To prevent damage, never
expose the device to any liquid or moisture. Avoid direct sunlight, heavy dirt, and
strong vibrations.

NOTICE!
Power supply

Before connecting the device, ensure that the input voltage (AC outlet) matches
the voltage rating of the device and that the AC outlet is protected by a residual
current circuit breaker. Failure to do so could result in damage to the device and
possibly injure the user.

Unplug the device before electrical storms occur and when it is unused for long
periods of time to reduce the risk of electric shock or fire.

Safety instructions

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NOTICE!
Magnetic fields

The device generates strong magnetic fields that can interfere with the function
of poorly shielded devices. The strongest magnetic fields are directly above and
below the power amplifier. Therefore, never place sensitive devices such as pre­amplifiers, radio transmission systems, or tape decks directly above or below the
power amplifier. When installing the power amplifier into a rack, you should place
it in the lowest position, and further equipment such as pre-amplifiers in the
highest position.

Safety instructions

S-75 • S-100 • S-150

11

3 Features

n Output power 2 × 45 W to 250 W (depending on the model)
n NL4 (Speakon) and binding-post connectors for speakers
n All protection circuits including soft start
n Input level can be switched from –0 to +4 db
n Fanless operation
n Automatic standby (can be disabled)

Features

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4 Connections and controls

Front panel

Connections and controls

S-75 • S-100 • S-150

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1 CH-1: Input level controller for channel 1

Use the input level controllers CH-1 and CH-2 (4) on the front panel to control the
signal amplification in the respective channel. If possible, turn this control fully to
the right stop (= 0 dB attenuation) for optimal headroom. Professional power
amplifiers then output their rated power, if the input voltage is 0.775 V resp. 1.4 V
(depending on the position of the switch for the input sensitivity [19]).

2/3 PEAK: Indicator for signal and maximum level

These LED chains indicate the output power of the device in the respective
channel. The PEAK indicator lights up when the output power reaches its max‐
imum. If this indicator lights up continuously, the volume of the respective channel
must be reduced. To do so, turn to the input level knob counter-clockwise.

4 CH-2: Input level controller for channel 2

Input level controller for channel 2, functionality is equal to point (1) .

Connections and controls

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5 PRO: Indicator for activated protection circuit

This indicator lights up, if one of the following situations arises in one of the chan‐
nels:

• 3-5 seconds after switching on, as the speakers are still electrically disconnected
from the power amp.

• The temperature of the output transistors exceeds 85°C.

• A malfunction exists in the device.

6 BR: Indicator for mono operation in bridged mode

Please read more about the available operating modes in chapter .

7 PAR: Indicator for mono operation in parallel mode

Please read more about the available operating modes in chapter .

Connections and controls

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8 POWER: Power indicator light

Lights up green when the unit is turned on. In standby mode, the LED lights red.
When the unit receives a signal again, it switches back to normal mode and the LED
lights green again.

9 POWER: On / off switch (9)

This switch turns the power on and off. When switching on the protection circuits
are activated. After a few seconds you will hear two "clicks" - now the speakers are
electrically connected to the amplifier and the device is ready to operate.

When switching on electronic devices, especially power amps, the power con‐
sumption is particularly high. Make sure you don't turn on too many devices simul‐
taneously. Otherwise, the power supply circuit may be overloaded and the RCD will
disconnect the power supply.

Connections and controls

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Rear panel

Connections and controls

S-75 • S-100 • S-150

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10 Mains connector with fuse holder

Connect the supplied power cord here and supply the device with mains voltage.

11 ERP ON | OFF

This switch enables/disables the standby feature. If enabled, the unit automatically
enters the standby mode when no input signal is present for at least fifteen
minutes.

12/13 Speaker outputs CH-1/2

Connect speakers to the speaker outputs of channel 1 and 2 using SPK cables
(wiring = 1+ 2+ 1– 2–).

14/15 Speaker terminals CH-1/2

You can connect the speakers either with cable lugs or bare wire to the cable termi‐
nals on the rear panel.

Connections and controls

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16 GROUND/LIFT switch

In normal operation signal source and power amplifier should share the same
ground potential. In some constellations this admittedly leads to ground loops and
thus to humming. If this happens vary the toggle switch setting for ground poten‐
tial on the rear panel of the unit. This switch connects in one setting the shield/
ground of the input signal with the housing of the power amp and thus with mains
earthing. In the other setting there is no electrical connection between the shield/
ground of the input signal and the power amp housing.

17 STE / PAR / BR

Use this switch to select the operating mode of the power amp: stereo (STE), par‐
allel (PAR) or bridged (BR).

18 CH-2

Connect the line-level signals to be amplified to the 1/4" balanced TRS phone jack
input of Channel 2 using a 1/4" phone jack cable.

19 CH-2

Connect the line-level signals to be amplified to the XLR input of Channel 2 using a
XLR cable.

Connections and controls

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20 0.77V | 1.4V | 26dB

The input level at which the power amplifier delivers its rated output power can be
switched between 0,775 V

RMS

and 1,4 V

RMS

. Often multiple amplifiers are used

simultaneously. In this case, switch to the "26 dB" position, the signal will then be
amplified by all amps equally. Thus, you can combine different power amps of the
S-series, and always get the same output level.

21 CH-1 (MONO)

Connect the line-level signals to be amplified to the XLR input of Channel 1 using a
XLR cable.

22 CH-1 (MONO)

Connect the line-level signals to be amplified to the 1/4" balanced TRS phone jack
input of Channel 1 using a 1/4" phone jack cable.

23 Switch for power supply voltage

Before connecting the amplifier to the mains power supply, ensure that the mains
voltage switch on the bottom side (or rear side for S-150) is in the position that cor‐
responds to the actual power available (in Germany AC 230 V). If in doubt, consult
an electrician.

Connections and controls

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5 Installation and starting up

Unpack and carefully check that there is no transportation damage before using the unit. Keep
the equipment packaging. To fully protect the device against vibration, dust and moisture
during transportation or storage use the original packaging or your own packaging material
suitable for transport or storage, respectively.

Establish all connections as long as the unit is switched off. Use the shortest possible high­quality cables for all connections.

DANGER!
Electric shock caused by high voltages at the power amplifier output

The output voltages of modern high-performance amplifiers may result in death
or serious injury.

Never touch the bare ends of loudspeaker cables when the amplifier is on.

Installation and starting up

S-75 • S-100 • S-150

21

NOTICE!
Magnetic fields

The device generates strong magnetic fields that can interfere with the function
of poorly shielded devices. The strongest magnetic fields are directly above and
below the power amplifier. Therefore, never place sensitive devices such as pre­amplifiers, radio transmission systems, or tape decks directly above or below the
power amplifier. When installing the power amplifier into a rack, you should place
it in the lowest position, and further equipment such as pre-amplifiers in the
highest position.

Models S-75 and S-100

The unit has been designed for rack mounting in a standard 19-inch rack; it occupies one rack
unit.

Rack mounting

Installation and starting up

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Model S-150

The device has been designed for rack mounting in a standard 19-inch rack; it occupies two
rack units.

Rack mounting

Installation and starting up

S-75 • S-100 • S-150

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5.1 Tips on handling speakers

We recommend you to set up the speakers in a way, that the sound signals can reach the audi‐
ence unobstructedly. It will often be helpful to mount the speakers on tripods. Thus, the sound
will be evenly spread with maximum range throughout the audience area.

Always use high grade cable to connect your equipment. Otherwise you won't reach max‐
imum sound quality.

For optimum results both impedance and power handling of the speakers must match the
requirements of the amplifier. Always follow the technical specifications of the speakers! The
overall impedance of the connected loudspeakers must not deceed the minimum output
impedance of the amp. The amps max. RMS output power should be 50 % above the power
handling capacity of the connected speakers.

If you notice distortion during operation, either the amp or the speaker is overloaded. This may
permanently damage the amp or the speaker. Always reduce the volume when you hear dis‐
tortion.

Installation and starting up

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5.2 More useful tips

Depending on the individual application, the amplifier can be used in different operation
modes:

Stereo mode

The two amplifier channels operate independently of
one another, either channel (CH1 and CH2) is amplified
and connected to loudspeakers, the volume can be con‐
trolled separately for the two outputs.

Parallel mode

The two amplifier channels receive the same input
signal from channel CH1 and loudspeakers are con‐
nected to each amplifier, the volume for both outputs is
controlled by the volume control of CH1.

Possible operation modes

Installation and starting up

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Bridged mode

The two amplifier channels are internally connected in
such a way that twice the output power is available.
Only the input signal from channel CH1 is amplified and
loudspeakers are connected only to the correspondingly
marked output. The volume is controlled by the volume
control of CH1.

For each output of the amplifier, the total impedance resulting from the loudspeakers con‐
nected to it must not be below the allowed minimal impedance of the amplifier output. If you
connect more than one loudspeaker to an amplifier output, please note the following:

n If the loudspeakers are connected in a series, the indivivudal impedances will be added up.
n If the loudspeakers are connected in parallel, the reciprocal of the total impedance equals

the sum of the reciprocals of the individual impedances.

Example: If you have two loudspeakers with the same impedance, their impedance doubles if
they are connected in a series, their impedance halves if they are connected in parallel.

For detailed information related to this topic please refer to our Online Guide ‘PA Speakers’
(www.thomann.de).

Installation and starting up

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6 Technical specifications

Model no. S-75 S-100 S-150

Output power
stereo 8 Ω 2 x 45 W 2 x 65 W 2 x 85 W
stereo 4 Ω 2 x 75 W 2 x 100 W 2 x 150 W
bridged 8 Ω 150 W 200 W 250 W
parallel 2 Ω 200 W
Frequency response 10 Hz - 50 kHz, -1.5 dB
Input sensitivity 0.77 V / 26 dB / 1.4 V
Maximum input level 21 dBV / 9 V
Input impedance, active balanced 20 kΩ
Signal-to-noise ratio, A-weighted, RMS > 80 dB > 85 dB
Crosstalk @ rated power, 8 Ω, 1 kHz > 70 dB

Technical specifications

S-75 • S-100 • S-150

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Model no. S-75 S-100 S-150

Damping factor, f=1 kHz, 8 Ω > 150 dB
Slew rate 35 V/µs 40 V/µs
Protection circuits

Short circuit current limit, DC voltage fault, fuse for power
supply, limiter, temperature, mains transients

Indicator lights Power (green), protection (yellow), clipping (red), bridged

mode operation (green), parallel mode operation (green)
Cooling Fanless
Power consumption @ half output power, 8 Ω 65 W 100 W 120 W
Power supply voltage AC 115 V / 230 V, 50-60 Hz
Dimensions (W × D × H) in mm 483 x 330 x 44 483 x 330 x 44 483 x 320 x 88

Technical specifications

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7 Plug and connection assignment

This chapter will help you select the right cables and plugs to connect your valuable equip‐
ment in such a way that a perfect sound experience is ensured.

Please note these advices, because especially in ‘Sound & Light’ caution is indicated: Even if a
plug fits into the socket, an incorrect connection may result in a destroyed power amp, a short
circuit or ‘just’ in poor transmission quality!

Unbalanced transmission is mainly used in semi-professional environment and in hifi use.
Instrument cables with two conductors (one core plus shielding) are typical representatives of
the unbalanced transmission. One conductor is ground and shielding while the signal is trans‐
mitted through the core.

Unbalanced transmission is susceptible to electromagnetic interference, especially at low
levels, such as microphone signals and when using long cables.

In a professional environment, therefore, the balanced transmission is preferred, because this
enables an undisturbed transmission of signals over long distances. In addition to the conduc‐
tors ‘Ground’ and ‘Signal’, in a balanced transmission a second core is added. This also transfers
the signal, but phase-shifted by 180°.

Introduction

Balanced and unbalanced trans‐
mission

Plug and connection assignment

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Since the interference affects both cores equally, by subtracting the phase-shifted signals, the
interfering signal is completely neutralized. The result is a pure signal without any noise inter‐
ference.

1 Signal
2 Ground, shielding

1 Signal (in phase, +)
2 Signal (out of phase, –)
3 Ground

1/4" TS phone plug (mono,
unbalanced)

1/4" TRS phone plug (mono, bal‐
anced)

Plug and connection assignment

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1 Signal (left)
2 Signal (right)
3 Ground

1 Signal
2 Ground

1/4" TRS phone plug (stereo,
unbalanced)

1/4" TS phone plug (mono,
unbalanced)

Plug and connection assignment

S-75 • S-100 • S-150

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1 Signal (in phase, +)
2 Signal (out of phase, –)
3 Ground

1 Signal (left)
2 Signal (right)
3 Ground, shielding

3.5 mm TRS phone plug (mono,
balanced)

Three-pole 1/8" mini phone jack
(stereo, unbalanced)

Plug and connection assignment

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1 Ground, shielding
2 Signal (in phase, +)
3 Signal (out of phase, –)

1 Ground, shielding
2 Signal
3 Bridged to pin 1

XLR plug (balanced)

XLR plug (unbalanced)

Plug and connection assignment

S-75 • S-100 • S-150

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1, + Signal 1 (in phase)
1, – Signal 1 (180 degree phase shift)
2, + Signal 2 (in phase)
2, – Signal 2 (180 degree phase shift)

NL4 mounting connectors

Plug and connection assignment

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8 Cleaning

The fan grids of the device must be cleaned on a regular basis to remove dust and dirt. Before
cleaning, switch off the device and disconnect AC-powered devices from the mains. Use a lint­free damp cloth for cleaning. Never use solvents or alcohol for cleaning.

Fan grids

Cleaning

S-75 • S-100 • S-150

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9 Protecting the environment

For the transport and protective packaging, environmentally friendly materials have been
chosen that can be supplied to normal recycling.

Ensure that plastic bags, packaging, etc. are properly disposed of.
Do not just dispose of these materials with your normal household waste, but make sure that

they are collected for recycling. Please follow the notes and markings on the packaging.

This product is subject to the European Waste Electrical and Electronic Equipment Directive
(WEEE). Do not dispose with your normal household waste.

Dispose of this device through an approved waste disposal firm or through your local waste
facility. When discarding the device, comply with the rules and regulations that apply in your
country. If in doubt, consult your local waste disposal facility.

Disposal of the packaging mate‐
rial

Disposal of your old device

Protecting the environment

power amplifier

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Notes

S-75 • S-100 • S-150

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Notes

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Musikhaus Thomann e.K. · Treppendorf 30 · 96138 Burgebrach · Germany · www.thomann.de