thomann the t.amp S-75 MK II User manual

S-75 MK II, S-100 MK II, S-150 MK II
Power Amplier
User Manual

Thomann GmbH
Hans-Thomann-Straße 1
96138 Burgebrach
Germany
Telephone: [phone]
Internet: www.thomann.de
24.08.2023, ID: 141140, 144356, 141141 (V6)

Table of contents
1 General information................................................................................................................................. 5
1.1 Symbols and signal words............................................................................................................... 5
2 Safety instructions..................................................................................................................................... 7
3 Features....................................................................................................................................................... 10
4 Connections and controls................................................................................................................... 11
5 Installation and starting up................................................................................................................ 17
5.1 Tips on handling speakers............................................................................................................ 19
5.2 Other useful hints............................................................................................................................. 20
6 Technical specications....................................................................................................................... 22
7 Plug and connection assignment.................................................................................................... 25
8 Cleaning....................................................................................................................................................... 30
9 Protecting the environment.............................................................................................................. 31
Table of contents
S-75 MK II, S-100 MK II, S-150 MK II 3
Power Amplier

4S-75 MK II, S-100 MK II, S-150 MK II
Power Amplier

1 General information
This document contains important instructions for the safe operation of the product. Read and
follow the safety instructions and all other instructions. Keep the document for future refer‐
ence. Make sure that it is available to all those using the product. If you sell the product to
another user, be sure that they also receive this document.
Our products and documentation are subject to a process of continuous development. They
are therefore subject to change. Please refer to the latest version of the documentation, which
is ready for download under www.thomann.de.
1.1 Symbols and signal words
In this section you will nd an overview of the meaning of symbols and signal words that are
used in this document.
General information
S-75 MK II, S-100 MK II, S-150 MK II 5
Power Amplier

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.
WARNING! This combination of symbol and signal word indicates a pos‐
sible dangerous situation that can result in death or serious
injury if it is not avoided.
NOTICE! This combination of symbol and signal word indicates a pos‐
sible dangerous situation that can result in material and
environmental damage if it is not avoided.
Warning signs Type of danger
Warning – high-voltage.
Warning – danger zone.
General information
6S-75 MK II, S-100 MK II, S-150 MK II
Power Amplier

2 Safety instructions
This device amplies 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 sucient 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.
Safety
DANGER!
Risk of injury and choking hazard for children!
Children can suocate on packaging material and small parts. Children can injure themselves when handling the device. Never allow
children to play with the packaging material and the device. Always store packaging material out of the reach of babies and small
children. Always dispose of packaging material properly when it is not in use. Never allow children to use the device without supervi‐
sion. Keep small parts away from children and make sure that the device does not shed any small parts (such knobs) that children
could play with.
DANGER!
Danger to life due to electric current!
Within the device there are areas where high voltages may be present. Never remove any covers. There are no user-serviceable parts
inside. Do not use the device when covers, safety equipment or optical components are missing or damaged.
Intended use
Safety instructions
S-75 MK II, S-100 MK II, S-150 MK II 7
Power Amplier

DANGER!
Danger to life due to electric current!
A short circuit could lead to a re hazard and risk of death. Always use proper ready-made insulated triple-core mains cable with a
safety plug. Do not modify the mains cable or the plug. In case of isolation damage, disconnect immediately the power supply and
arrange repair. If in doubt, seek advice from a qualied electrician.
WARNING!
Possible hearing damage due to high volumes on speakers or headphones!
With speakers or headphones connected, the device can produce volume levels that may cause temporary or permanent hearing
impairment. Over an extended period of time, even levels that seem to be uncritical can cause hearing damage. 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 re due to covered vents and neighbouring heat sources!
If the vents of the device are covered or the device is operated in the immediate vicinity of other heat sources, the device can over‐
heat and burst into ames. Never cover the device or the vents. Do not install the device in the immediate vicinity of other heat
sources. Never operate the device in the immediate vicinity of naked ames.
NOTICE!
Damage to the device if operated in unsuitable ambient conditions!
The device can be damaged if it is operated in unsuitable ambient conditions. Only operate the device indoors within the ambient
conditions specied in the “Technical specications” chapter of this user manual. Avoid operating it in environments with direct sun‐
light, heavy dirt and strong vibrations. Avoid operating it in environments with strong temperature uctuations. If temperature uc‐
tuations cannot be avoided (for example after transport in low outside temperatures), do not switch on the device immediately.
Never subject the device to liquids or moisture. Never move the device to another location while it is in operation. In environments
with increased dirt levels (for example due to dust, smoke, nicotine or mist): Have the device cleaned by qualied specialists at reg‐
ular intervals to prevent damage due to overheating and other malfunctions.
Safety instructions
8S-75 MK II, S-100 MK II, S-150 MK II
Power Amplier

NOTICE!
Damage to the device due to high voltages!
The device can be damaged if it is operated with the incorrect voltage or if high voltage peaks occur. In the worst case, excess vol‐
tages can also cause a risk of injury and res. Make sure that the voltage specication on the device matches the local power grid
before plugging in the device. Only operate the device from professionally installed mains sockets that are protected by a residual
current circuit breaker (FI). As a precaution, disconnect the device from the power grid when storms are approaching or it the device
will not be used for a longer period.
NOTICE!
Risk of re due to installation of a wrong fuse!
Using fuses of a dierent type than compatible with the device may cause a re and seriously damage the device. Only use fuses of
the same type. Observe the labelling on the device casing and the information in the "Technical data” chapter.
NOTICE!
Interference with nearby electrical devices due to magnetic elds!
The device generates strong magnetic elds that can interfere with the function of poorly shielded devices. The magnetic elds are
strongest directly above and below the Power Amplier. You should therefore never place sensitive devices such as pre-ampliers,
radio transmission systems, or tape decks directly above or below the Power Amplier. When placing the Power Amplier in a rack,
you should place it at the bottom thereof, and place any other equipment at the top of the rack.
NOTICE!
Possible staining due to plasticiser in rubber feet!
The plasticiser contained in the rubber feet of this product may react with the coating of the oor and cause permanent dark stains
after some time. If necessary, use a suitable mat or felt slide to prevent direct contact between the device’s rubber feet and the oor.
Safety instructions
S-75 MK II, S-100 MK II, S-150 MK II 9
Power Amplier

3 Features
nOutput power 2 × 45 W to 250 W (depending on the model)
nSpeaker Twist and terminal connections for speakers
nAll protection circuits incl. soft start
nInput level switchable from –0 to +4 db
nFanless operation
nStandby function
Features
10 S-75 MK II, S-100 MK II, S-150 MK II
Power Amplier

4 Connections and controls
Front
Connections and controls
S-75 MK II, S-100 MK II, S-150 MK II 11
Power Amplier

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 amplication in the respec‐
tive channel. If possible, turn this control fully to the right stop (= 0 dB attenuation) for optimal headroom. Profes‐
sional power ampliers then output their rated power, if the input voltage is 0.775 V or 1.4 V (depending on the posi‐
tion of the switch for the input sensitivity [19]).
2/3 [PEAK] | Indicator for level / maximum level
These LED chains indicate the output power of the device in the respective. The PEAK indicator lights up when the
output power reaches its maximum. 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).
5[PRO] | Indicator for activated protection circuit
This indicator lights up, if one of the following situations arises in one of the channels:
• 3-5 seconds after switching on, as the speakers are still electrically disconnected from the power amplier.
• The temperature of the power amplier 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 Ä ‘Possible operation modes’ on page 20.
Connections and controls
12 S-75 MK II, S-100 MK II, S-150 MK II
Power Amplier

7[PAR] | Indicator for mono operation in parallel mode
Please read more about the available operating modes in chapter Ä ‘Possible operation modes’ on page 20.
8[POWER] | Power indicator light
Lights up green when the device is turned on. In standby mode, the LED lights up red. As soon as the unit receives a
signal, it switches back to normal mode and the LED will light up green again.
9[POWER] | ON/OFF switch
Use this mains switch to turn the device on or o. The protection circuits are activated when the device is switched
on. After a few seconds you will hear two ‘clicks’ - now the speakers are electrically connected to the power amplier
and the device is ready to operate.
Electronic devices, and power ampliers in particular, have especially high power consumption while they are
switched on. Make sure not to turn on too many devices simultaneously. Otherwise you could overload the power
supply circuit and trigger its fuse.
Connections and controls
S-75 MK II, S-100 MK II, S-150 MK II 13
Power Amplier

+
ERP
ON OFF
115V~ 230V~
VOLTAGE SELECTION
115V/230V ~, 50/60Hz
F:T5AL 250V (230V~)
F:T10AL 250V (115V~)
CH-1
CH-1CH-2
CH-2
S-150 mk2
OUTPUT
INPUT
, - . 0
/21 3 4 6 7
5
ERP
ON OFF
115V/230V ~, 50/60Hz
F:T5AL 250V (230V~)
F:T10AL 250V (115V~)
CH-1 CH-1CH-2CH-2
OUTPUT INPUT
8 + - .
0
/
,
21 3 4 6 7 5
Back
Connections and controls
14 S-75 MK II, S-100 MK II, S-150 MK II
Power Amplier

10 Mains connector with fuse holder
Connect the supplied power cord here and supply the device with mains voltage.
11 [ERP ON | OFF] | On / o switch for the standby function
If the standby function is enabled, the device automatically switches to standby mode after 20 minutes without any
input signal.
12/13 [CH-1/2] | Speaker outputs
Connect speakers to the speaker outputs of channels 1 and 2 using SPK cables (wiring = 1+ 2+ 1– 2–).
14/15 [CH-1/2] | Speaker terminals
You can connect the speakers to the cable terminals on the rear panel using either cable lugs or bare wire.
16 [GROUND/LIFT] | Earthing switch
In normal operation, the signal source and the power amplier(s) should share the same ground potential. In some
constellations this can however lead to ground loops and thus to humming. If this happens, vary the toggle switch
setting for ground potential on the rear panel of the device. In once setting, this switch connects the shield/ground
of the input signal to the housing of the power amplier and thus to mains earthing. In the other setting there is no
electrical connection between the shield/ground of the input signal and the power amplier housing.
17 [STE / PAR / BR] | Operating mode switch
Use this switch to select the operating mode of the power amplier: stereo (STE), parallel (PAR) or bridged (BR).
18 [CH-2] | Signal input jack
Connect the line-level signal to be amplied to the 6.35 mm balanced jack input of channel with a jack cable.
Connections and controls
S-75 MK II, S-100 MK II, S-150 MK II 15
Power Amplier

19 [CH-2] | Signal input XLR
Connect the line-level signal to be amplied to the XLR input of channel 2 using an XLR cable.
20 [0.77V | 1.4V | 26dB] | Operating mode switch
The input sensitivity at which the power amplier delivers its full rated power can be set with this switch between
0.775 VRMS and 1.4 VRMS). Often multiple power ampliers are used simultaneously. In this case, switch to the “26 dB”
position, and the signal will be amplied equally with 26 dB by all power ampliers. You can combine dierent power
ampliers of the S-series and always get the same output level.
21 [CH-1 (MONO)] | Signal input XLR
Connect the line-level signal to be amplied to the XLR input of channel 1 using an XLR cable.
22 [CH-1 (MONO)] | Signal input jack
Connect the line-level signal to be amplied to the 6.35 mm balanced jack input of channel 1 with a jack cable.
23 [VOLTAGE SELECTION] | Supply voltage selection switch
Before connecting the amplier to the mains power supply, ensure that the mains voltage switch on the bottom of
the device (or on the side for S-150) is in the position that corresponds to the actual power available (230 V~ in Ger‐
many). If in doubt, consult an electrician.
Connections and controls
16 S-75 MK II, S-100 MK II, S-150 MK II
Power Amplier

5 Installation and starting up
Unpack and check carefully there is no transportation damage before using the unit. Keep the
equipment packaging. To fully protect the product against vibration, dust and moisture during
transportation or storage use the original packaging or your own packaging material suitable
for transport or storage, respectively.
Create all connections while the device is o. Use the shortest possible high-quality cables for
all connections. Take care when running the cables to prevent tripping hazards.
Installation and starting up
S-75 MK II, S-100 MK II, S-150 MK II 17
Power Amplier

DANGER!
Risk of death from electrical current!
The output voltages of modern high-performance ampliers may result in death
or serious injury.
Never touch the bare ends of loudspeaker cables when the amplier is on.
NOTICE!
Interference with nearby electrical devices due to magnetic elds!
The device generates strong magnetic elds that can interfere with the function
of poorly shielded devices. The magnetic elds are strongest directly above and
below the Power Amplier.
You should therefore never place sensitive devices such as pre-ampliers, radio
transmission systems, or tape decks directly above or below the Power Amplier.
When placing the Power Amplier in a rack, you should place it at the bottom
thereof, and place any other equipment at the top of the rack.
Models S-75 and S-100
The device is designed for mounting in a standard 19-inch rack; it occupies one rack unit (RU).
Model S-150
Rack mounting
Installation and starting up
18 S-75 MK II, S-100 MK II, S-150 MK II
Power Amplier

The device is designed for mounting in 19-inch racks, it occupies two rack units (RU).
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 amplier. Always follow the technical specications 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
S-75 MK II, S-100 MK II, S-150 MK II 19
Power Amplier

5.2 Other useful hints
Depending on the individual application, the amplier can be used in dierent operation
modes:
Stereo mode
The two amplier channels operate independently of
one another, either channel (CH1 and CH2) is amplied
and connected to loudspeakers, the volume can be con‐
trolled separately for the two outputs.
Parallel mode
The two amplier channels receive the same input
signal from channel CH1 and loudspeakers are con‐
nected to each amplier, the volume for both outputs is
controlled by the volume control of CH1.
Bridged mode
The two amplier channels are internally connected in
such a way that twice the output power is available.
Only the input signal from channel CH1 is amplied and
loudspeakers are connected only to the correspondingly
marked output. The volume is controlled by the volume
control of CH1.
Possible operation modes
Installation and starting up
20 S-75 MK II, S-100 MK II, S-150 MK II
Power Amplier