thomann Harley Benton PA-250 User manual

PA-250
power attenuator
user manual

Musikhaus Thomann
Thomann GmbH
Hans-Thomann-Straße 1
96138 Burgebrach
Germany
Telephone: [phone]
E-mail: [email protected]
Internet: www.thomann.de
18.01.2021, ID: 510412

Table of contents
1 General information................................................................................................................................. 4
1.1 Further information........................................................................................................................... 5
1.2 Notational conventions.................................................................................................................... 6
1.3 Symbols and signal words............................................................................................................... 6
2 Safety instructions..................................................................................................................................... 8
3 Features....................................................................................................................................................... 13
4 Connections and controls................................................................................................................... 14
5 Technical specications....................................................................................................................... 18
6 Plug and connection assignment.................................................................................................... 20
7 Cleaning....................................................................................................................................................... 23
8 Protecting the environment.............................................................................................................. 24
Table of contents
PA-250
3

1 General information
This user manual contains important information on the 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 to another user, be sure
that they also receive this manual.
Our products and user manuals are subject to a process of continuous development. We there‐
fore reserve the right to make changes without notice. Please refer to the latest version of the
user manual which is ready for download under www.thomann.de.
General information
power attenuator
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1.1 Further information
On our website (www.thomann.de) you will nd lots of further information and details on the
following points:
Download This manual is also available as PDF le for you to download.
Keyword search Use the search function in the electronic version to nd the topics of
interest for you quickly.
Online guides Our online guides provide detailed information on technical basics
and terms.
Personal consultation For personal consultation please contact our technical hotline.
Service If you have any problems with the device the customer service will
gladly assist you.
General information
PA-250
5

1.2 Notational conventions
This manual uses the following notational conventions:
The letterings for connectors and controls are marked by square brackets and italics.
Examples: [VOLUME] control, [Mono] button.
1.3 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 manual.
Letterings
General information
power attenuator
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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 pos‐
sible dangerous situation that can result in minor 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
PA-250
7

2 Safety instructions
This device is used to attenuate the output level of guitar amps. Use the device only as
described in this user manual. Any other use or use under other operating conditions is consid‐
ered 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.
Intended use
Safety instructions
power attenuator
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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.
Safety
Safety instructions
PA-250
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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.
Do not use the device if covers, protectors or optical components are missing or
damaged.
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.
Safety instructions
power attenuator
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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.
Only operate the device within the ambient conditions specied in the chapter
‘Technical specications’ of this user manual. Avoid heavy temperature uctua‐
tions and do not switch the device on immediately after it was exposed to tem‐
perature uctuations (for example after transport at low outside temperatures).
Dust and dirt inside can damage the unit. When operated in harmful ambient
conditions (dust, smoke, nicotine, fog, etc.), the unit should be maintained by
qualied service personnel at regular intervals to prevent overheating and other
malfunction.
Safety instructions
PA-250
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NOTICE!
Damages caused by the connection to an enabled amplier
Always connect the device to a disabled amplier, otherwise the amplier may be
damaged.
NOTICE!
Possible staining
The plasticiser contained in the rubber feet of this product may possibly react
with the coating of your parquet, linoleum, laminate or PVC oor and after some
time cause permanent dark stains.
In case of doubt, do not put the rubber feet directly on the oor, but use felt-pad
oor protectors or a carpet.
Safety instructions
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3 Features
Power soak for tube ampliers, ideal for use in rehearsal rooms, recording studios and on
stage.
nInput power handling: max. 250 Watt
n8 Ω option, 16 Ω option
nInput: Amp
nOutputs: Mixing console/recording device (low-Z), line, speaker
nLED as overload indicator
nControls: Speaker level, line level, ne level
nSilent fan
Features
PA-250
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4 Connections and controls
Connections and controls
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1[BY PASS]
Toggle switch for disabling the power reducer. The LED lights.
The signal volume is output as if the speaker out is directly connected to the amplier.
2[POWER (db)]
Rotary control for adjusting the signal volume at the speaker out. Turn the control counter-clockwise to reduce the
volume of the output signal in steps of 2…3 dB.
Turn the control to ‘–15’ to enable the rotary control [FINE].
3 LED as overload indicator
4[8 Ω / 16 Ω]
Rotary control for adjusting the impedance. The corresponding LED lights.
The impedance must be set to the same value on the Power Attenuator, on the connected amplier and on the
speaker.
Connections and controls
PA-250
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5[FINE]
Rotary control for adjusting the eective signal volume at the speaker out. The LED lights.
Turn the control clockwise to reduce the output signal volume en steps of 4…5 dB up to ‘–∞’ (no sound).
If you turn the control to ‘–15’ , the eective volume is –15 dB less than the not-attenuated volume.
6[LOAD]
Toggle switch for muting the connected speaker. The connected amplier is still on with full power. The LED lights.
7[BALANCED OUT]
Low-impedance XLR output for connecting a mixing console or recording device.
8[GND LIFT]
Switch for disconnecting the grounding to avoid unwanted hum noises caused by ground loops.
9[LINE OUT]
Line output for connecting an eects processor or power amp.
The LED [OUT] lights when an eects processor or a power amp is connected.
10 [LINE LEVEL]
Rotary control for adjusting the signal volume at the line out.
Connections and controls
power attenuator
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11 [POWER]
Input socket for the power adapter
12 [AUX POWER]
Status LED. The LED lights when the device is operational and the fan runs.
13 [INPUT FROM AMP]
Input socket for connecting an amplier.
The impedance must be set to the same value on the Power Attenuator and on the connected amplier.
Connect the device always to the disconnected amplier, otherwise the amplier may be damaged.
14 [8 Ω / BY PASS / 16 Ω]
Status LED. The LED lights when the function is activated.
15 [OUTPUT FROM SPEAKER]
Output jack for connecting a passive speaker box.
Connections and controls
PA-250
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5 Technical specications
Max. input power handling 250 watt
Inputs Input socket for the power adapter
1 × 1/4" phone socket
Input impedance 8 Ω, 16 Ω
Outputs 1 × XLR (low-Z)
2 × 1/4" phone socket
Power supply External power adapter, 9 - 24 V 50/60 Hz
Dimensions (W × H × D) 235 mm × 88 mm × 179 mm
Weight 2.7 kg
Ambient conditions Temperature range 0 °C…40 °C
Relative humidity 50 %, non-condensing
Technical specications
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Noise reduction No
DI box No
Speaker simulation Yes
Dummy Load (operation without
box)
Yes
Further information
Technical specications
PA-250
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6 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 ts 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 hi 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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