Lake People MPA RS 01 User manual

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MICROPHONE PRE-AMPLIFIER
MPA RS 01
USER´s MANUAL

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Content
Theme Page
About Lake People 3
Safety Instructions 5
The Earth / Groun ing Concept 7
Connection / Connectors 9
General 9
Operation 10
Theory an practice: the gain stage 13
Operation 13
Dismantling 16
Jumper Setting 17
Technical Data 18
Conformity Statement 19
Warranty 20

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Cord al thanks for your dec s on n favour of a
Lake People product !
Lake People electronic GmbH evelops, manufactures an istributes
pro ucts in the professional range, for broa cast, television, airports,
exhibition halls, festival venues, theatres, large-scale installations,
private stu ios an more. In the private sector as well, Lake People
pro ucts become increasingly popular ue to their outstan ing quality.
Who develops Lake People equ pment ?
The evices are exclusively evelope in Germany by the engineers of
Lake People electronic GmbH. In oing so, the team of evelopers can
raw on thirty years of experience an countless pro ucts for the pro-
au io omain.
Among others, the first German-ma e 20-bit A/D an D/A converters
were evelope by Lake People in the early nineties of the past century.
Who manufactures Lake People equ pment ?
The evices are exclusively manufacture in Germany by Lake People
electronic GmbH or contractors in the company's vicinity.
Lake People puts high emphasis on omestic manufacturing. As well, all
component suppliers are chosen in or er achieve the main part of
a e value inlan .
How do Lake People dev ces get to the customer ?
Lake People evices can be obtaine from respective specialist
suppliers. If there is none such accessible regionally, the customer is
supporte by transregional istribution partners (google may help...)
an , of course, by Lake People on-line shop.

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… and f t doesn't work l ke t should ?
Lake People evices are covere by a 24-month warranty. In case of
any malfunction uring this perio , they can be shippe to the
manufacturer irectly. Of course, the client will benefit from Lake
People's full technical support even when warranty has expire . Any
technical questions or nee for a vice is welcome.
LAKE PEOPLE electron c GmbH
Turmstrasse 7a
D-78467 Konstanz
Fon [phone]
Fax [phone]
Ma l: [email protected]
www.v olectr c.de www.v olectr c.com
www.lake-people.de www.lake-people.com

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General Safety Instruct ons
WARNING
For your protect on, please read the follow ng:
Water, L qu ds, Mo sture
This appliance shoul not be use near water or other sources of
liqui s. Care shoul be taken so that objects o not fall an liqui s are
not spille into the enclosure through openings.
Power Sources
The appliance shoul be connecte to a power supply only of the type
escribe in the operating instructions or as marke on the appliance.
Fuse
The fuse of this appliance is sol ere in place an accessible from the
insi e only!!
A blown fuse may in icate an internal problem an shoul be replace
uring qualifie servicing or repair works, !!
Power Supply
The unit shoul be operate with the provi e wall-plug a aptor – but
also stan ar USB cell-phone supplies are suitable.
However, because of the sometimes relatively thin cables of these
evices, there might be a significant voltage rop on the cable which
might impair the proper operation of MPA RS 01.
Other (USB) power sources may be use un er the following
circumstances:
- a proper DC voltage within the range of 5 – 5,5 V
- a current capacity of min 1 A

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Serv ce / Repa r:
To re uce the risk of fire or electric shock, the user shoul not attempt to
service the appliance beyon the measures escribe in the operating
manual. All other servicing or repair shoul be referre to qualifie
personnel !!
Electromagnet c Compat b l ty
This unit conforms to the Pro uct Specifications note as Declarat on
of Conform ty at the en of this manual. Operation is subject to the
following con itions:
- this evice may not cause harmful interferences
- this evice must accept any interference receive ,
inclu ing interference that may cause un esire operation
- this evice must not be operate within significant
electromagnetic fiel
VOR DEM ÖFFNEN NETZSTECKER
ZIEHEN!! PULL MAINS BEFORE
OPENING!! AVANT D´OUVRIER
RETIREZ LA FICHE MALE!!

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The Earth / Ground ng Concept
THE EARTH/GROUND CONCEPT
This unit is powere by an external source an thus is not inclu ing a
power cor with groun /earth facilities.
The internal reference point (Groun ) is connecte to the case !!
XLR GROUD-LIFT Jumper
(accessible from the insi e, see also page 17)
To minimize or avoi groun buzz an hum the earth-groun
relationship may be altere as follows:
G(ROUND):
Ex works all jumpers are set to G(ROUND) position. Pin 1 is connecte
to the internal groun reference. High frequency interferences are
eflecte to the case via a 100 nF capacitor.

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L(IFT):
The interconnection between Pin 1 an groun is open. High frequency
interferences are eflecte to the case via a 100 nF capacitor. This
jumper position is useful when the unit is equippe with transformers !!
C(ASE):
Pin 1 is connecte to the case, the 100 nF capacitor is bri ge .
Please note that w th jumpers n LIFT or CASE pos t on
EMC problems m ght occur.
These are n the f eld of the user´s respons b l ty !!!!
Connect on / Connectors

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GENERAL
The LAKE PEOPLE MPA RS 01 is an excellent an extremely low-noise
2-channel microphone preamplifier in a compact “Desk-Top” case.
Due to its versatile concept an high level capability it is also suitable for
line signal boosting an balancing.
Gain is controlle with a twelve-step rotary switch which sets gain in 6-
B steps from 0 to +66 B.
Each channel is equippe with switches for Phase Reverse an Low
Cut. 48V Phantom supply may be activate for both channels
simultaneously. The state of all these switches is reporte by LEDs.
A seven-segment LED bargraph isplays the output level over a range
of 36 B. Display sensitivity can be a juste internally to the user's
requirements.
The inputs an outputs are situate on the back panel, they are
equippe with gol plate XLR connectors for balance output signals
an RCA connectors for unbalance output signals.
FEATURES
- 2 balance inputs via XLR
- Gain switchable from 0 ... +66 B in 12 steps of 6 B
- Switchable Lo-Cut, 12 B/Oct. with 70 Hz corner
- Switchable phase reverse
- Noise -129 B @ 60 B gain
- 7-segment level control, -36 … 0 Br, internally a justable
- Electronically balance output via XLR
- Further unbalance outputs via RCA
- Switchable phantom supply, 48 Volt
- Power supply via USB Typ B, 5 - 5.5 V, 1 A
THE CASE
The case is ma e of aluminum inclu ing the front an back panel. This
provi es high mechanical stability an resistance against rough
han ling. The cases surfaces are black ano ize .

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EARTH AND GROUD
This unit is operate with an external wall plug a aptor an so is not
groun e by a 3-wire mains cor . The internal reference point (groun )
is connecte to the case an may be lifte by means of a jumper (see
page 17). Sometimes it may be helpful to a itionally connect the case
to an external earth/groun potential.
THE POWER SUPPLY
MPA RS 01 shoul be operate with the provi e wall-plug a aptor, but
also any other USB supply is suitable.
However, because of the often relatively thin cables of these evices,
there might be a significant voltage rop on the cable which might impair
the proper operation of MPA RS 01.
Other USB power sources may be use un er the following
circumstances:
- a proper DC voltage within the range of 5 – 5,5 V
- a current capacity of min 1 A
THE FUSE
The fuse of this appliance is sol ere in place an accessible from the
insi e only !!
A blown fuse may in icate an internal problem an shoul be replace
uring qualifie servicing or repair works !!
CAUTION !!
MIND THE SAFETY INSTRUCTIONS:
A blown fuse in icates an internal fault an
shoul be replace uring qualifie repair or
servicing only !!

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THE POWER SWITCH
The unit is activate by means of the power switch. Power-on status is
in icate by the green “ON” LED.
THE INPUTS
The back mounte balance inputs appear as gol plate XLR
connectors. They are marke “LEFT CH 1” an “RIGHT CH 2”.
The inputs accept balance as well as unbalance au io signals.
XLR wiring correspon s to international stan ar with
- Pin 1 = groun ,
- Pin 2 = + (in phase) an
- Pin 3 = - (out of phase).
If an unbalance source must be connecte , one of the phases
(preferably the negative one) shoul be connecte to signal groun
(see page 8).

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PHANTOM POWERING
The use of professional con enser microphones requires so-calle
phantom powering.
The MPA RS 01 offers stabilize 48V phantom powering, which is
activate by the "48 V"-button on the front panel.
This voltage is applie to pins 2 an 3 via matche 6.8 kOhm resistors
of both input connectors.
Active phantom powering is in icate by the re "ON"-LED.
NOTE:
Switching the phantom power uring operation pro uces low-frequency
voltage swing at the MPA RS 01's output. To avoi amage of monitor
lou speakers or other equipment, the subsequent input shoul be
mute when activating or eactivating the phantom power.
NOTE:
If unbalance equipment such as synthesizers etc. is connecte to the
MPA RS 01's inputs, the 48V phantom voltage might cause amage if
the connection is not ma e properly.
This problem is face with all phantom powere inputs an can be
avoi e by using a transformer couple D.I. box or by strictly keeping
the unbalance wiring apart from pin 1 (groun ).

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GAIN SETTING
The input signal applie to the XLR terminal is fe to an extremely low-
noise integrate instrumentation amplifier.
Gain is set by the "GAIN"-rotary switch in 6 B steps from 0 to +66 B.
The eviation from the in icate value is less than +/- 0.3 B.
THE AMPLIFIER STAGE: THEORY AND PRACTICE
The MPA RS 01's gain is affecte by a so calle instrumentation
amplifier. It is represente by an IC specially esigne for this task,
istinguishing itself by very low noise figures an a high gain/ban wi th
pro uct.
When gain is set to +60 B (x1000), the amount of noise a e is only
approx. 2 B more than the theoretically achievable minimum.
The gain/ban wi th pro uct (GBW) an the slew rate are basically
responsible for the sonic quality of an amplifier. The higher they are, the
more transparent the soun becomes.
Slew rate is 10V/s, while the GBW is calculate from the frequency
response at a certain gain ratio.
The MPA RS 01's internal linear frequency response at +60 B gain
excee s 200 kHz. The resulting GBW is as high as 200 MHz (200.000
Hz x 1000).
PHASE REVERSE
In multiple microphone applications, inverting one or several
microphones´ phase can significantly improve the overall mix.
Reason therefore may be position- epen ent time lags between
microphones or, in the worst case, an incorrectly sol ere microphone
lea .
The "PHASE"-switch inverts signal polarity an is confirme by the
yellow "REV"- LED.

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LOW CUT
In or er to re uce un esire frequencies such as win or microphone
han ling noise, the MPA RS 01 offers a Low-Cut Filter with a corner
frequency of 70 Hz.
It is inserte into the signal path by the "LOW-CUT"-Switch situate on
the front panel. Active state is isplaye by the "70 Hz"- LED.
LEVEL METER
Situate on the front panel between the gain switches, a seven-segment
LED bar-graph isplays the momentary output level. The overall isplay
range is 36 B.
The ynamic characteristics are accor ing to DIN specifications, with a
rise time of <10 millisecon s an 1.5 secon s release time for a 20 B
level change.
The isplay's sensitivity can be a juste on the main PCB to meet user-
specific requirements (see page 17 for etails).
Ex works the re 0 Br LED is a juste to a level of +15 Bu.
Please note that MPA RS 01 is able to output a level of over +20 Bu,
thus a hea room of 5 B remains.

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THE OUTPUTS (balanced)
Each channel offers a balance output with gol plate XLR-type
connectors. They are situate on the rear of the unit an
marke "LEFT / CH 1” an “RIGHT / CH 2”.
The polarity meets AES 14-1992:
1 = Groun , 2 = (+) Phase, 3 = (-) Phase
The output impe ance is approx. 30 ohms.
HINT:
In case of unbalance termination of these outputs, pin 3 of the XLR
connector may not be shortene but must be left open!
Signal level is re uce by 6 B!
THE OUTPUTS (unbalanced)
MPA RS 01 offers a itional unbalance outputs with gol plate RCA
connectors. They are situate on the rear of the unit an marke "L / 1”
an “R / 2”.
Please note that the level on these outputs is 6 B lower than the
balance level.

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DISMANTLING / JUMPER SETTINGs
H nt:
Here we are talking about internal a justments insi e your MPA RS 01.
You are in nee of a screw rivers TORX style size T10 or a 2,5 mm
hex allen key.
You shoul by all means
DISCONNECT THE POWER SUPPLY!!!
DISMANTLING
To avoi amages please follow the instruction below:
1. screw off both upper screws on the front panel
2. screw off both upper screws on the back panel
3. now lift the upper li
4. make your personal jumper settings
Assemble the unit in reverse or er.

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JUMPER SETTING MPA RS 01

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TECHNICAL DATA MPA RS 01
All measurement RMS unweighte , 20 Hz - 20 kHz, relativ to 0 Bu as
not otherwise note
Number of channels: 2
Input: electronically balance
Input impe ance: 5 kOhm
Input CMRR (15 kHz): < 60 B (G = 0 B) / < 80 B (G = +60 B)
max. input level: > +20 Bu
Gain: 0...+66 B in 12 Steps of 6 B
(Accuracy < 0.3 B)
Phantom voltage: 48 Volt ( +/- 5 %)
Phase reverse switchable: 180
o
Lo-cut: 70 Hz (-3 B), 12 B/oct. 2-pol filter
Internal Ban wi th (-3 B): > 200 kHz (@ +60 B gain)
Frequency range: 5 Hz....40 kHz (-0.5 B)
THD+N: < 0.002% (G=0 B) / 0.03 % (G=+60 B)
Noise (Rin = 200 Ohm): < -100 B (G=0 B) / -69 B (G=+60 B)
max. output level (sym.): > +20 Bu in RL > 600 Ohm
Output CMRR (15 kHz): < -60 B
Level isplay: 7 LEDs, range 36 B, a justable
Characteristic referre to DIN: Attack <10ms, Release 1.5 s (20 B)
Internal voltages: Au io voltages +/- 15 Volt,
Phantom +48 Volt, +/- 5%
Logic voltage +5 Volt, +/- 5 %
Allgeme n
External power supply: via USB 5 – 5.5 V, 1 A
Case, front, back: Aluminum, black ano ize
Dimensions: 168 x 49 x 145 mm (W x H x D)

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EC CONFORMITY STATEMENT:
We herewith eclare that the following unit
Name: VIOLECTRIC MPA RS 01
Serial No. : -all -
is in conformity with the following EC irectives:
2006/95/EG Low voltage irective
20014/30/EC EMC irective
EN 60065:2002+A12:2011 Security irectives for au io-,
JIS C6065:2013 vi eo- un similar electronic evices
2001/95/EC General Pro uct Safety Directive
For verification of conformity with regar to electromagnetic compatibility the
following harmonize stan ar s are applie :
EN 50081-1:1992 Generic emission stan ar
EN 50082-1:1992 Generic immunity stan ar
Pro uct family stan ar for au io, vi eo, au io-visual entertainment apparatus:
EN 55013:2001 EN 61000-3-2:2000
EN 55020:2002 EN 61000-3-3:1995
2011/65/EU, RoHS irective
2012/19/EU, WEEE irective / Member No.: DE 26076388
This eclaration is given un er responsibility of:
Konstanz 06.03.2016 Frie Reim CEO
LAKE PEOPLE
electronic GmbH
Turmstrasse 7a
D-78467 Konstanz
Fon [phone]
Fax [phone]

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WARRANTY
Since 1986 we are constructing an manufacturing sophisticate
electronics for ambitious customers.
Since the early beginnings we are trying har by accompanying
measures, the use of 1st choice components an multiple quality
checks uring pro uction to avoi faults at large.
We are quite effective in that an this is – amongst others - why we
enjoy such a goo reputation.
Despite all accurateness faults may show up which may erogate the
proper operation of your pro uct.
In this case your unit is protecte by a 2-year Warranty !
Nee less to say that we will care for your pro uct even after the
expiration of the warranty. If it is necessary please ispatch your item to:
Lake People electronic GmbH Fon [phone]
Turmstrasse 7a Fax [phone]
D-78467 Konstanz E-Mail info@lake-people. e
Your warranty claim begins with the ate of purchase, which shoul be enote on your
proof of purchase.
In case of return o not forget to inclu e the receipt of sales or a copy of the receipt.
Please also inclu e a short escription of the fault(s).
For the reshipment we nee you correct a ress !!
Care for a safe packaging. Best is to use the original packaging.
Please keep in min that we cannot accept collect freight.
We will grant a quick repair an quick return of the unit.
In case of a warranty repair we will reship free of charge.
Please enote here the serial number an the ate of purchase:
Serial Number Date of Purchase