AKG PERCEPTION 820 TUBE User Manual
PERCEPTION 820 TUBE
USER INSTRUCTIONS . . . . . . . .p. 2
Please read the manual before using the equipment!
MODE D’EMPLOI . . . . . . . . . . . . . . . .p. 20
Veuillez lire cette notice avant d’utiliser le système!
Table of Contents
Page
1 Safety and Environment...............................................................................................................3
1.1 Symbols Used .......................................................................................................................3
1.2 Safety Instructions .................................................................................................................3
1.3 Environment..........................................................................................................................3
2 Description ..................................................................................................................................4
2.1 Introduction...........................................................................................................................4
2.2 Packing List ..........................................................................................................................4
2.3 Optional Accessories..............................................................................................................4
2.4 Microphone...........................................................................................................................4
2.5 Remote Control Unit...............................................................................................................4
2.5.1 Front Panel...................................................................................................................5
2.5.2 Rear Panel ...................................................................................................................5
3 Setting Up....................................................................................................................................7
3.1 Important Note ......................................................................................................................7
3.2 Connecting the Microphone....................................................................................................7
3.3 Connecting the Remote Control Unit to Power...........................................................................7
3.4 Powering Up..........................................................................................................................7
3.5 Powering Down .....................................................................................................................8
4 Using the Microphone..................................................................................................................9
4.1 Introduction...........................................................................................................................9
4.2 Bass Cut Filter .......................................................................................................................9
4.3 Preattenuation Pad ..............................................................................................................10
4.4 Hints on Microphone Placement............................................................................................10
4.4.1 Lead Vocals................................................................................................................10
4.4.2 Choir/Backing Vocals...................................................................................................10
4.4.3 Trumpet, Trombone .....................................................................................................11
4.4.4 Electric Guitar/Bass.....................................................................................................12
4.4.5 Violin, Viola .................................................................................................................12
4.4.6 Double Bass, Cello ......................................................................................................13
4.4.7 Acoustic Guitar ...........................................................................................................13
4.4.8 Flute ..........................................................................................................................13
4.4.9 Clarinet......................................................................................................................14
4.4.10 Tenor and Soprano Saxophones .................................................................................14
4.4.11 Grand and Upright Pianos ..........................................................................................14
4.4.12 Drums .....................................................................................................................15
5 Cleaning ....................................................................................................................................16
6 Troubleshooting.........................................................................................................................16
6.1 Replacing the Fuse ...............................................................................................................16
6.2 Solving Problems..................................................................................................................17
7 Specifications............................................................................................................................18
7.1 Microphone.........................................................................................................................18
7.2 Remote Control Unit.............................................................................................................18
Frequency Response and Polar Patterns.......................................................................................19
Conformity....................................................................................................................................38
2 PERCEPTION 820 TUBE
1 Safety and Environment
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The lightning flash with arrowpoint in an equilateral triangle means that there are
dangerous voltages present within the unit.
↯
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The exclamation point in an equilateral triangle on the equipment indicates that it
is necessary for the user to refer to the User Manual. In the User Manual, this
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symbol marks instructions that the user must follow to ensure safe operation of
the equipment.
1. Do not spill any liquids on the equipment and do not drop any objects through the ventilation slots in the equipment.
2. Use the equipment in dry rooms only. Do not expose the equipment to rain or splash
water. Never place objects containing liquids (e.g., vases) on or near the equipment.
3. There are no user-serviceable parts inside the equipment. Do not attempt to service the
equipment yourself. Refer all servicing to qualified personnel. Opening the chassis for any
reason will void the manufacturer’s warranty.
4. Before connecting the equipment to power, check that the AC mains voltage stated on
the power supply included with the equipment is identical to the AC mains voltage available where you will use the equipment. Also check that the power outlet is a standard
type with a protective ground connection. Disconnecting the protective ground lead or
using non-standard power plugs or non-standard power outlets is illegal.
5. Operate the equipment with the power supply included with the equipment only. Using
a different power supply may cause serious damage to the unit.
6. If any solid object or liquid penetrates into the equipment, shut down the sound system
immediately. Disconnect the equipment from power immediately and have the equipment
checked by AKG service personnel.
7. If you will not use the equipment for a long period of time, disconnect the equipment from
power. Please note that the equipment will not be fully isolated from power when you set
the power switch to OFF.
8. Disconnect the equipment from power during storms to prevent damage.
9. Make sure to route power supply cords so that they are not likely to be walked on or
pinched by items placed upon or against them, paying particular attention to cords at
plugs, convenience receptacles, and the point where they exit from the equipment.
10. To avoid hum or interference, route all audio lines, particularly those connected to microphone inputs, away from power lines of any type. If you use cable ducts, be sure to
use separate ducts for the audio lines.
11. Make sure to replace the built-in fuse with a standard fuse of the same type and rating
only. Using any other type of fuse may cause excessive heating and/or a risk of fire.
12. Do not place the equipment near heat sources such as radiators, heating ducts, or amplifiers, etc. and do not expose it to direct sunlight, excessive dust, moisture, rain, mechanical vibrations, or shock.
13. Clean the equipment with a moistened (not wet) cloth only. Be sure to disconnect the
equipment from power before cleaning the equipment! Never use caustic or scouring
cleaners or cleaning agents containing alcohol or solvents since these may damage the
enamel and plastic parts.
14. Use the equipment for the applications described in this manual only. AKG cannot accept any liability for damage resulting from improper handling or misuse.
1.1 Symbols Used
1.2 Safety Instructions
1. When scrapping the equipment, separate the case, circuit boards, and cables, and dispose of all components in accordance with local waste disposal rules.
2. The packaging of the equipment is recyclable. Dispose of the packaging in an appropriate
container provided by the local waste collection/recycling entity and observe all local
legislation relating to waste disposal and recycling.
1.3 Environment
3PERCEPTION 820 TUBE
2 Description
2.1 Introduction
2.2 Packing List
2.3 Optional Accessories
2.4 Microphone
Thank you for purchasing an AKG product. This Manual contains important instructions for
setting up and operating your equipment. Please take a few minutes to read the instruc-
tions below carefully before operating the equipment. Please keep the Manual for future reference. Have fun and impress your audience!
• PERCEPTION 820 TUBE microphone
• Remote Control Unit
• Audio/control cable
• Spider-type shock mount
• US type power cord
• UK type power cord
• European type power cord
• Check that the packaging contains all of the items listed above. Should any of these
items be missing, please contact your AKG dealer.
• For optional accessories, refer to the current AKG catalog or folder, or visit www.akg.com.
Your dealer will be glad to help.
The PERCEPTION 820 TUBE is a high quality, true condenser microphone with a 1-inch dual
large-diaphragm transducer.
What sets it apart from other condenser microphones is that it uses a vacuum-tube preamplifier. Unlike conventional solid-state electronics, a tube preamplifier adds even-order harmonics to the signal. Although these are low in level, they create a rich, warm,
three-dimensional sound. This characteristic in conjunction with the typical response of the
large-diaphragm transducer will give your recordings a degree of warmth and “musicality”
that is difficult to achieve with solid-state microphones.
The microphone incorporates a carefully selected ECC 83 tube. If the tube needs replacing,
you may alternatively use a 12AX7 tube. This type is similar to the ECC 83.
Other features of the PERCEPTION 820 TUBE include:
• Selectable polar patterns: The microphone’s transducer uses a dual diaphragm. This
sophisticated technology allows you to select the optimum polar pattern (cardioid, omnidirectional, figure eight, and six intermediate patterns) for every application.
• Gold-sputtered diaphragm: The diaphragm is made of a plastic foil that is gold-sputtered on one side only to prevent shorting to the back electrode even at extremely high
sound pressure levels.
• All-metal body: The all-metal body adds to the rejection of RF interference so you can
use the microphone near transmitter stations and along with wireless microphones or
other communications equipment. The extremely rugged, heavy body and sturdy front
grill protect the microphone from damage from tough handling on stage.
• High headroom: Capable of handling sound pressure levels up to 155 dB and built to
resist high temperatures and humidity, the microphone will give excellent results in a wide
range of applications.
2.5 Remote Control Unit
4 PERCEPTION 820 TUBE
The Remote Control Unit delivered with your microphone
• provides the filament and plate voltages for the vacuum tube,
• supplies the polarization voltage for the transducer,
• lets you select one of nine different polar patterns,
• provides a 20-dB preattenuation pad, and
• allows you to switch in a bass cut filter.
2 Description
BCD
A
2.5.1 Front Panel
Fig. 1: Controls on the
Remote Control Unit
front panel.
A POWER LED: This blue LED is lit to indicate that power to the Remote Control Unit is ON.
B Polar pattern selector: This rotary switch lets you select the microphone’s polar pat-
tern from omnidirectional (fully CCW) to cardioid (center) to figure eight (fully CW). Between these settings, there are six intermediate patterns. All switch positions are
detented, so all settings are easily and unambiguously reproducible.
C Preattenuation switch: This toggle switch lets you increase the microphone’s headroom
by 20 dB for close-in recording with extremely low distortion. The preattenuation pad prevents the microphone's output level, particularly at low frequencies, from overloading the
miniature transformers used in many mixer input stages, etc.
D Bass cut switch: This toggle switch lets you reduce low-end distortion caused by foot-
fall or wind noise, etc. The bass cut filter also minimizes the proximity effect that closein miking from less than 4 inches causes in any unidirectional microphone. The filter
rolls off at 12 dB/octave from 80 Hz downward.
E
E POWER switch: Turns power to the unit ON (position “I”) and OFF (position “0”). The front
panel POWER LED is lit while power is ON and goes out when you turn power to the unit
OFF.
F AC input: Standard IEC power receptacle with integrated fuse holder.
• To avoid damage, use replacement fuses of the same type and rating (125 mA/
250 V, slow-blow) only.
G Power voltage selector: Sets the input power voltage to 210 - 240 VAC (“210-240V”
position) or 110 - 120 VAC (“110-120V” position).
F
G
H I
J
Refer to fig. 1.
2.5.2 Rear Panel
Fig. 2: Controls, inputs, and
outputs on the Remote
Control Unit rear panel.
Refer to fig. 2.
Important!
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• To avoid damage, always make sure that the power voltage selector is set to the
same voltage as the power voltage available where you are going to use the unit.
H INPUT: 7-pin female XLR connector for connecting the dedicated audio/control cable
for the microphone.
I OUTPUT: This balanced 3-pin XLR connector provides the microphone output signal.
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Important!
5PERCEPTION 820 TUBE
2 Description
Refer to fig. 2 on page 5.
J GROUND LIFT: This pushbutton switch allows you to remove hum caused by ground
loops.
To open the chassis ground connection, press the GROUND LIFT button OUT (“LIFT” position).
To restore the chassis ground connection, press the GROUND LIFT button IN (“GROUND”
position).
6 PERCEPTION 820 TUBE
3 Setting Up
• To avoid damage or electric shock, mount the microphone on a suitable stand
and make all audio connections before connecting the Remote Control Unit to
power.
D
B
A
C
1. Use the supplied audio/control cable (A) to connect the microphone output to the INPUT
connector(B) on the Remote Control Unit rear panel.
2. Use a standard balanced XLR cable (C) (optional) to connect the OUTPUT connector (D)
on the Remote Control Unit rear panel to the desired microphone input on your mixer.
1. Prior to connecting the Remote Control Unit to power, check what power voltage is available where you are going to use the microphone.
2. Set the power voltage selector (G) on the rear panel to the correct position as shown in
Table 1 below.
3.1 Important Note
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3.2 Connecting
the Microphone
Fig. 3: Connecting the microphone to the Remote Control
Unit and mixer.
Refer to fig. 3.
3.3 Connecting
the Remote Control Unit
to Power
Refer to fig. 2 on page 5.
Power voltage Selector setting Power cord
210 to 240 VAC, 50/60 Hz 210-240V UK or European type
110 to 120 VAC, 50/60 Hz 110-120V US type
3. Referring to Table 1 above, use the correct power cord to connect the Remote Control
Unit to a grounded power outlet.
When on tour, you may encounter power outlets that do not match the power plug on
any of the supplied power cords.
• Purchase a suitable power cord locally that complies with IEC and local safety
standards and has a power plug with a chassis ground pin.
• To avoid damage or electric shock, connect the Remote Control Unit to a grounded
power outlet only.
• If in doubt about the power connection, consult a local electrician.
• Set the power switch on the Remote Control Unit rear panel to “I”.
After about ten seconds, the heating voltage will have reached the specified level and
the front panel POWER LED will be lit. About twenty seconds later, the microphone will
be ready to operate.
• You may not get the full splendor of the tube sound before the electrodes have reached
the required operating temperature. Therefore, we recommend powering up at least
Table 1: Power voltage vs. selector setting and power cord
Important!
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3.4 Powering Up
Note:
7PERCEPTION 820 TUBE
3 Setting Up
five minutes before starting to record. This will allow the tube inside the microphone
to heat up properly,
3.5 Powering Down
1. Set the power switch on the Remote Control Unit rear panel to “0”.
The front panel POWER LED will go out.
2. Wait for five minutes to allow the tube to cool down to room temperature before moving the microphone. A hot tube will be more susceptible to mechanical damage than a
cold one.
8 PERCEPTION 820 TUBE
4 Using the Microphone
Using vacuum-tube electronics and a large-diaphragm transducer, the PERCEPTION 820
TUBE is suited for a wide range of applications. It will add the typical warmth and richness
tube microphones are famous for to female and male voices as well as many instruments.
The following sections contain general hints on using the microphone and suggestions on
how to place the microphone for voices and various instruments.
• Please remember that vacuum tubes with their heater filaments are more delicate than
solid-state components. Even a drop from moderate height may cause the filament to
break and the microphone to fail. So always handle the microphone with extreme care.
• Refer to fig. 4. Whichever polar pattern you select, it may be good to know which way
the transducer axis is facing: the front of the microphone is the side of the body with the
AKG logo on it.
• When recording wind instruments or vocals, make sure not to blow or sing directly into
the microphone.
To get professional sounding results with no unwanted wind and pop noise (exaggerated
“p” and “t” sounds), place an optional PF 80 pop screen from AKG between the microphone and vocalist/instrument.
• Keep the microphone dry. Moisture from blowing or singing directly at the capsule from
a short distance, or extremely high humidity may cause the microphone to start crackling or go very quiet due to partial short circuits in the polarization voltage.
• If you use the microphone in the open, use an optional AKG W 4000 windscreen to protect the microphone from moisture and reduce wind noise.
• Loud instruments: You can use this microphone for close-in recording of very loud instruments (brass instruments, kick drum, etc.). Just switch the preattenuation pad in to
increase the microphone’s capability of handling sound pressure levels to 155 dB.
- To switch the preattenuation pad in, set the preattenuation switch on the Remote
Control Unit front panel to “-20 dB”.
- To switch the preattenuation pad out of circuit, set the preattenuation switch to “0”.
4.1 Introduction
Note:
4.2 General Hints
• Low-frequency noise: The supplied spider type shock mount reduces footfall or other mechanical noise to a minimum.
The switchable bass cut filter at 80 Hz will effectively suppress any remaining low-frequency noise such as fan noise from air conditioning systems, etc., or floor vibrations,
handling noise, etc. without affecting the sound of the recorded voice or instrument on
tape.
- To switch the filter in, set the bass cut filter switch on the Remote Control Unit front
panel to the “ “ position.
- To switch the filter out of circuit, set the bass cut filter switch on the Remote Con-
trol Unit front panel to the “—“ position.
Fig. 4: Microphone front.
9PERCEPTION 820 TUBE
4 Using the Microphone
4.3 Selecting
Polar Patterns
4.4 Hints on Microphone
Placement
4.4.1 Lead Vocals
Each of the PERCEPTION 820 TUBE’s selectable polar patterns is virtually frequency independent so that reflected sound, too will be reproduced accurately and uncolored.
• Omnidirectional (left-hand setting): This is the preferred setting for “all around the
mic” recording, high quality ambience (audience sound) miking, or far-field recording in
exceptionally good-sounding large or small recording rooms, etc.
• Cardioid (center setting): This is a standard setting for recording and gives excellent
results on all kinds of voices and a wide range of instruments. Remember to aim the microphone front (see fig. 4 on page 8) at the sound source.
• Figure eight (right-hand setting): The microphone will pick up sounds arriving from the
front and rear with equal sensitivity. Use this mode to mic up the side signal in M/S
stereo recording or to record two sound sources (talkers, instruments) facing each other.
It is also a good choice for cymbal overhead miking.
Every instrument radiates its sound in a specific way. Therefore, to get the best sound, do
not hesitate to experiment with microphone placement.
As an introduction to the “secret science of making good recordings”, the following sections
describe some proven miking techniques. (Illustrations show generic microphones.)
• Place the microphone 6 to 12 in.
(15 to 30 cm) from the vocalist’s
mouth.
• Select the cardioid polar pattern:
set the polar pattern selector to
cardioid ( ).
• Switch the bass cut filter in: set
the bass cut switch to “ ”.
• We strongly recommend placing
a PF 80 pop screen (available as
an optional accessory) between
the microphone and vocalist to
eliminate pop noise.
• To give the vocalist better control
of their own voice, we recommend adding the vocalist's track
to their headphone monitor signal.
Fig. 5: Solo vocalist.
4.4.2 Choir/
Backing Vocals
B T A S
P 820
Fig. 6: Miking a large
mixed choir.
10 PERCEPTION 820 TUBE
P 820 P 820 P 820
60°60°
• To record large mixed choirs, we
recommend using a pair of cardioid microphones to get a stereo
signal, plus one PERCEPTION 820
TUBE each for the soprano, alto,
tenor, and bass sections.
- Set each PERCEPTION 820
TUBE to cardioid ( ).
- Place each microphone about
5 feet (1.5 m) in front of the respective section, about 6 feet
(1.8 m) above the ground.
- Aim each microphone at the
center of its assigned section.
4 Using the Microphone
• In rooms with good acoustics,
a pair of PERCEPTION 820
TUBEs will often do the trick.
- Set each microphone to
cardioid ( ).
- Use an optional H 50 stereo
bar to mount the two microphones on a stand.
• Place the stereo pair about
10 feet (3 m) in front of the
choir, about 8 feet (2.4 m)
above the ground.
- Aim the stereo pair at the
center of the choir.
- Turn the left-hand micro-
phone 60 degrees to the left and the right-hand microphone 60 degrees to the right.
Backing vocals/technique 1:
Refer to section 4.4.1 Lead Vocals above.
• If you have enough tracks available, we recommend overdubbing each voice separately.
Backing vocals/technique 2:
• If you use a separate microphone for each of several vocalists simultaneously, set each
microphone to hypercardioid (a
position between and )
to prevent crosstalk, particularly
if you place the microphones
close to one another.
B T A S
60°60°
H 50
Fig. 7: Using a stereo pair to
record a choir.
Backing vocals/technique 3:
• Refer to fig. 8. If you use a single microphone for the entire
group, select the cardioid
( ) or omni ( ) pattern and
place the vocalists in a semicircle in front of the microphone.
• Place the microphone about 1 foot (30 cm) in
front of the instrument, slightly off the bell
axis.
• Switch the preattenuation pad in.
• To reduce blowing noise, a PF 80 pop screen
(available as an optional accessory) between
the microphone and
instrument.
Fig. 8: Backing vocalists
sharing a single microphone.
4.4.3 Trumpet, Trombone
a
b
Fig. 9: Trumpet (a),
trombone (b).
11PERCEPTION 820 TUBE
4 Using the Microphone
4.4.4 Electric Guitar/Bass
Fig. 10: Electric guitar.
4.4.5 Violin, Viola
Electric guitar:
• Position the microphone 1 to
6 inches (2.5 to 15 cm) in front
of the speaker, aiming at a point
just off the speaker diaphragm
center.
• Use the bass cut and preattenuation pad.
• You may want to use an additional distant microphone to capture the sound of the speaker
cabinet as it interacts with the
room.
Electric bass:
• Use the same technique as for the electric guitar.
• You can use a DI box to add the direct signal of the line output on the bass amp to the
microphone signal.
Solo violin:
• Set the polar pattern selector to
cardioid ( ) or omnidirectional
().
• Direct the microphone at the f
holes from a height of 6 to 8 feet
(1.8 to 2.5 m) above the floor.
Viola:
• Set the polar pattern selector to
cardioid ( ) or omnidirectional
().
• Direct the microphone to the f
holes from a height of 7 to
10 feet (2.2 to 3 m) above the
floor.
Fig. 11: Violin.
Large string sections:
• Use a combination of a main microphone in an XY, MS, ORTF, or other stereo configuration and close-in spot microphones.
12 PERCEPTION 820 TUBE
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