Speck MicPre 5.0 User manual

MicPre 5.0
Microphone Preamp & Mix Node
Reference Manual

Speck Electronics products are warranted to the original owner to be free of
defects in material or workmanship.
This warranty does not apply to any product subject to accident, misuse, neglect
or failure to comply with normal maintenance procedures or if the serial number
has been defaced, altered, or removed; nor will Speck Electronics accept
responsibility for damages resulting from improper installation, alteration or
unauthorized parts or repairs. If the product is modified by the customer without
permission, the customer agrees to pay for parts and labor necessary to remove
the modification before repair. The cause of the defect is in the sole judgment of
Speck Electronics.
Should a defect develop within one year of purchase from Speck Electronics or
an authorized dealer, Speck Electronics will supply the part or parts necessary at
no charge. Labor is covered in this warranty for a period of one year. Outside
service, repairs or pickups are not covered under this warranty.
Any item returned for warranty repair should be sent, if possible, in the original
packing container, prepaid to Speck Electronics, 341 E. Alvarado Street,
Fallbrook, California, 92028. If in our opinion the packing container is
improper for return shipping, we reserve the right to supply a new container at a
minimal charge.
In the interest of improving Speck products; designs and specifications are
subject to change without notice. It should be mentioned that if a change is
necessary for any reason, we make every effort to document
that change and send an "update notice" to all customers at no charge.
Speck Electronics makes no warranty of any kind with regard to this material,
including, but not limited to, the implied warranties of merchantability and
fitness for a particular purpose. Speck Electronics shall not be liable for errors
contained herein or for incidental consequential damages in connection with the
furnishing, performance, or use of this material.
This document contains proprietary information which is protected by copyright.
All rights are reserved. No part of this document may be photocopied,
reproduced, or translated into another language without the prior written consent
of Speck Electronics.
The information contained in this document is subject to change without notice.
All trademarks are the property of their respective owners.
First Printing - September 2002
Speck Electronics
341 East Alvarado Street
Fallbrook, California 92028
USA
760-723-4281
www.speck.com
Warranty
Notice
Edition
ii

Contents
General .................................................................................
Standard Accessories ............................................................
Optional Accessories ............................................................
Operator Safety Summary .......................................................
Power source ........................................................................
Grounding the product .........................................................
Removing the cover .............................................................
General .................................................................................
Unpacking and inspection ....................................................
Environmental considerations ..............................................
Electrical grounding safety ..................................................
Mechanical installation ........................................................
Physical placement of adjacent equipment ..........................
Cleaning ...............................................................................
Repacking for shipment .......................................................
Basic connections to the MicPre 5.0 ........................................
The Input / Output connectors .............................................
Insert jacks ...........................................................................
Mixoutput jacks ...................................................................
Wiring the MP 5.0 to unbalanced inputs...............................
Mix Link Connector .............................................................
Connecting the MP 5.0 to the ASC Equalizer .............................
Interfacing two MP 5.0's..............................................................
Interfacing more than two MP 5.0's.............................................
Interfacing two MP 5.0's for M-S operation................................
General..................................................................................
Default control settings .........................................................
Signal flow diagram..............................................................
Front Panel Controls ................................................................
Gain switch............................................................................
Trim control ..........................................................................
Mic/DI select switch .............................................................
D.I. input jack .......................................................................
20dB Pad...............................................................................
48V Phantom switch .............................................................
Phase switch..........................................................................
Output select switch..............................................................
High Pass Filter control ........................................................
Filter bypass switch...............................................................
VU Meter ..............................................................................
Power indicator .....................................................................
Mix Level control .................................................................
Mix Pan control.....................................................................
Mix Mute switch ...................................................................
1
2
2
2
2
2
3
5
5
5
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Chapter 1 Introduction
Chapter 2 Installation
Chapter 3 Operation
iii

Rear Panel .................................................................................
Microphone input ..................................................................
Preamp output ......................................................................
O.S.P. switch .........................................................................
Insert jacks ...........................................................................
Pre Out-B / Line In jacks .....................................................
Mix output jacks ...................................................................
Mix Link connector ..............................................................
Aux DC output .....................................................................
Power switch ........................................................................
AC power inlet......................................................................
Fuse .......................................................................................
Specifications..............................................................................
General .................................................................................
Start simple ..........................................................................
Audio Cable ................................................................................
Connectors ...........................................................................
AC Distribution and safety .........................................................
Proper AC grounding ...........................................................
Quality AC system ...............................................................
AC distribution .....................................................................
Clock noise and AC .............................................................
Safety earth connection ........................................................
Audio earth ...........................................................................
Proper audio grounding and shielding ........................................
EMI and RFI ...............................................................................
Sources of EMI ....................................................................
Reducing EMI ......................................................................
20
20
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Chapter 4 Wiring and Other
iv

v

Introduction
Chapter 1 Introduction Section 1
Thank you for purchasing our MicPre 5.0 microphone
preamplifier. The MicPre 5.0 has operational features that are easy
to understand and you should be up and running in no time. If you
are unfamiliar with audio equipment or audio signal flow, it is
recommended that you read this manual. If you have any
questions regarding the MicPre 5.0 or any Speck product, do not
hesitate to contact Speck Electronics. Our phone number is
[phone].
The MicPre 5.0 is a complete single channel microphone preamp
that offers features and flexibility for use in recording, live sound
or any application that requires a high quality microphone preamp.
„In this manual the MicPre 5.0 will also be referred to
as the MP 5.0.
The signal path consists of a matched discrete transistor front-end,
premium IC's, and transformer output stage. With the push of a
button, the MP 5.0 can change from a "Transformer-Balanced"
output to a "Active-Balanced" output.
The MP 5.0 also includes a mix section that makes it perfect for
DAW's and remote recording. With an optional interface cable, the
mix section of the MP 5.0 can linked with additional MP 5.0’s to
form a fully integrated mix section.
The compact ½ rack format of the MP5.0 can easily be rack
mounted and combined with the Speck Model ASC equalizer to
create a highly functional outboard channel strip.
The MicPre 5.0 is available in 2 versions; The Model MP5.0-NA
designed to operate with 100 and 120 VAC power, and the Model
MP5.0-EU that is designed to operate with 220, 230 or 240 VAC
power.
General
MicPre 5.0 - Microphone Preamp and Mix Node

The MP5.0 is supplied with the following list of accessories:
Operations Manual
Power cord (NA version only)
(4) rubber bumpers - used for table top mounting or
stacking multiple units.
(2) 6-32 x ½” machine screws - supplied to mount the
MP 5.0 to an optional rack shelf.
The following is a list of optional accessories that are available
from the factory or your Speck dealer:
Mix link interface cables - to interface additional
MP 5.0’s.
2 unit cable - P/N MP50-Link2
4 unit cable - P/N MP50-Link4
6 unit cable - P/N MP50-Link6
8 unit cable - P/N MP50-Link8
M-S interface cable - a 12” cable used to connect two
MP5.0’s for use in a M-S micing configuration.
P/N MP50-MS
D.C. interface cable - Used to supply power to the
Model ASC equalizer.
P/N ASC-DCI
1U rack tray - may be used to rack mount two
MP 5.0’s or one MP 5.0 and one Model ASC equalizer.
The MP 5.0 is intended to operate from an AC power source that
does not apply more than 120 Volts RMS (Model MP5.0-NA) or
240 Volts RMS (Model MP5.0-EU) between the supply
conductors. Always make certain that power cord matches the
operating voltage shown on the rear panel above the power switch.
To avoid electrical shock, plug the power cord into a properly
wired receptacle. The ground pin of the power cord is internally
connected to the chassis. For safety reasons, do not lift the
ground on the power plug by using a ground lift adapter.
The MicPre 5.0 should never be exposed to rain or moisture.
Standard accessories
Optional accessories
Power Source
Grounding the product
Chapter 1 Introduction Section 2
Operator Saftey
Summary

To avoid personal injury, do not remove the top cover of the
MP 5.0 and never operate the MP 5.0 without the cover properly
installed.
The MP 5.0 with its internal power supply contains voltages that
can cause serious injury or death. Refer all repairs to a qualified
service technician, or directly to Speck Electronics.
Do not remove the cover
Chapter 1 Introduction Section 3

Chapter 1 Introduction Section 4
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Installation
The following information should give you the basics on how to
install the MP 5.0. The proper installation of the MP 5.0 as part of
a larger system requires a clear understanding of audio wiring, AC
distribution, grounding, and shielding techniques.
When the MP 5.0 is being installed into a larger system it may be
necessary to retain the services of someone experienced in these
matters.
The MP 5.0 is delivered in a special, protective shipping container
and was carefully inspected both mechanically and electrically
before shipment. It should be physically free of mars and scratches
and in perfect electrical order upon receipt. To confirm this, the
product should be inspected for physical damage that may have
occurred in transit. Any damage should be reported to your
delivery company as soon as possible.
If installed in an equipment rack that also contains heat producing
equipment, adequate ventilation should be provided. This will
prolong component life and maximize operational stability.
To insure adequate airflow around the unit and to prevent
overheating, we recommend leaving a 1U blank panel above and
below the MP 5.0 and do not obstruct the air vents on the side.
While the internal circuitry of the MP 5.0 is fully shielded by the
steel chassis, installation should nevertheless be planned to avoid
locating it immediately adjacent to power amplifiers, power
supplies, or any source of low frequency electromagnetic
emissions.
Merely affixing the MP 5.0 into an equipment rack is no guarantee
that the product is making a reliable ground connection. The
mounting rails in the equipment rack should never be depended
upon for a ground connection. To protect operating personnel, the
National Electrical Manufacturers Association (NEMA)
recommends that rack cabinets be grounded.
Upon loss of a protective ground connection, all accessible
conductive parts, including knobs and controls that may appear to
be insulating, can render an electric shock.
General
Unpacking and inspection
Electrical grounding safety
Environmental considerations
Chapter 2 Installation Section 5

To avoid electrical shock, plug the MP 5.0 into a properly wired
receptacle. The ground pin of the power cord is internally
connected to the chassis. For safety reasons, do not lift the
ground on the power plug by using a ground lift adapter.
The location of the MP 5.0 should be such that the operator has a
clear, unobstructed view of the front panel from his/her normal
operating position. The unit should also be within easy reach of
the operators normal position in order to facilitate the use of the
front panel controls
The ½ rack form factor of the MP 5.0 allows a single unit to be
mounted on a table top with the (4) rubber bumpers supplied with
the unit, multiple units stacked, or two units mounted side-by-side
on a 1U rack shelf manufactured by Middle Atlantic Products
(Model UTR1).
When attaching the MP 5.0 to the rack shelf, it should be secured
with the (2) 6-32 x ½” machine screws supplied with the unit. Do
not use screws that are longer than ½” in length as they could
damage the internal circuit board. When the MP 5.0 or multiple
MP 5.0’s are mounted to the rack shelf, they may be installed into
any 19" wide equipment rack that uses standard E.I.A. universal
spacing.
Any device that emits a high EMI (Electro Magnetic Interference)
or RFI (Radio Frequency Interference) energy field should be
treated with suspicion. EMI is considered any unwanted signal
which adversely affects the operation of the MP 5.0 or the audio
system. This subject is discussed in Chapter 4.
Electronic equipment such as power amplifiers, power supplies,
video monitors, computers, certain synths and samplers must be
located away from the MP 5.0 and its associated audio cables. It
may be necessary to alter the positions of certain equipment that
you feel would cause buzzes or hums in the audio system.
Mechanical installation
Physical placement of
adjacent equipment
Chapter 2 Installation Section 6

The front panel is a high quality painted surface and the panel
lettering is applied using a silkscreen printing technique.
To clean the front panel, wipe the surface gently using a soft lint-
free cloth to avoid scratching the panel or markings. Paper towels
are not recommended. Commercially available window cleaner
solutions may be used; however, the solution should be applied to
the cloth and not the panel to avoid the seepage of liquid to the
inside of the enclosure.
If the MP 5.0 is to be shipped to Speck Electronics for service or
repair, attach a tag to the product identifying the owner and
indicating the service or repair to be accomplished. Include the
model number and serial number of the product. Place the product
in the original container if available. If the original container in
not available, a suitable one can be purchased from Speck
Electronics.
If the original container is not used, wrap the product in heavy
plastic before placing in an inner container. Use plenty of packing
material around all sides of the product and protect panel faces
with cardboard strips. Mark shipping container with "Delicate
Instrument" or "Fragile", and insure the shipment for the proper
amount.
Note: Speck Electronics cannot be responsible for equipment that
arrives damaged or uninsured.
Cleaning
Repacking for shipment
Chapter 2 Installation Section 7

Basic connections
to the MicPre 5.0
Input / Output connectors
Insert jacks
Mix output jacks
Chapter 2 Installation Section 8
The XL mic input and XL pre output are the primary connections
to the MP 5.0. The XL microphone input (1) is designed to receive
a signal from any low impedance balanced microphone. The
preamp output (2) is a line level output and is switchable from
"Transformer-Balanced" or "Active-Balanced" output.
The Insert Send (3) and Insert Return (4) jacks provides line
level interstage access to connect a limiter or equalizer. Any
device interfaced to these jacks will be processed after the main
preamp gain stage and before the high pass filter section. The
processed signal is available at the main XL output, the left and
right mix outputs and the left/right output terminals on the mix link
connector.
The active-balanced TRS insert jacks serve a secondary function
on the MP 5.0. The Insert Send may be used as an additional
balanced Pre Out-B (3) and the Insert Return may be used as an
auxiliary Line In (4).
The active-balanced TRS left and right Mix Outputs (5) provide a
low impedance source for connection to the input of any balanced
line input.
The output circuits of the MP 5.0 were designed for balanced lines
and should only be connected to balanced inputs. If that is not
possible and it is necessary to connect to an unbalanced input, care
must be taken not to connect the low (-) terminal to ground.
If the low (-) terminal of these outputs are connected to ground, the
result will be a high level of audio distortion.
Wiring the MP 5.0
to unbalanced inputs
DIRECT
OUTPUT
INPUT
MIX LINK
speck
electronics
S/N
MIX LEFT
INSERT RTN
PRE OUT-B
INSERT SEND
LINE IN
AUX DC OUT
MicPre 5.0
MIX RIGHT
O.S.P.
OR
NORMAL
1
2
5
6
43

PIN 2PIN 2
PIN 3PIN 3
PIN 4PIN 4
PIN 5PIN 5
PIN 6PIN 6
PIN 6PIN 6
PIN 8PIN 8
Mix Out - LeftMix Out - Left
Mix Out - RightMix Out - Right
GroundGround
Sum In- LeftSum In- Left
Sum In - RightSum In - Right
GroundGround
PIN 1PIN 1
Figure 3. Pin-outs for mix link connector
Chapter 2 Installation Section 9
If wiring the XL Pre Out for unbalanced operation, the cable
should be wired according to the diagram shown below in
Figure 1.
If wiring the Insert Send (Pre Out-B) or Mix Outs for unbalanced
operation, the cable should be wired according to the diagram
shown below in Figure 2.
The Mix Link connector (6) is a RJ45 modular jack that allows the
mix section of the MP 5.0 to be combined with additional
MP 5.0's. The terminals on the mix link connector include the
left/right mix outputs and the left/right summing inputs.
A selection of standard and custom interface cables used to link the
MP 5.0’s are available from Speck Electronics or may be
assembled using standard 8 pin RJ45 modular plugs and 4
conductor cable.
The Pin-outs for the mix link connector are shown below in
Figure 3.
Mix Link Connector
18
Figure 1. Unbalanced wiring for XL output
Shield Shield
To MP 5.0 XL output To unbalanced input
Do not
connect pin 3
12
3
Figure 2. Unbalanced wiring for TRS outputs
Shield
To MP 5.0 output jack To unbalanced input
Do not connect
ring terminal

Connecting the MP 5.0
to the Model ASC EQ
With only a few simple connections, the MP 5.0 can be combined with
the Speck Electronics "Model ASC" 4 band equalizer to form a single
channel strip.
The following illustration shows how to interface the ASC equalizer to
the insert send/return jacks of the MP5.0 and how to power the ASC
from the Aux DC power source of the MP 5.0.
If you use the optional ASC-DCI cable, do not use the ASC power
module for the installation.
Connect one end of the ASC-DCI interface cable (green mark - face up)
to the connection marked “Aux DC Out” on the MP5.0. Connect the
other end of the interface cable (green mark - face up) to the connection
marked “Aux DC I/O” on the ASC. The plugs and respective connectors
are keyed so they will fit in only one direction.
USE WITH SPECK
PRODUCTS ONLY
OUTPUT INPUT
speck
electronics
Model ASC - 4 Band Equalizer
OUTPUT TRANSFORMER OPTION
Fallbrook, California
S/N
POWER
AUX DC I/O
USE WITH PS-4
POWER MODULE
LIFT
BAL. XLR
BAL. ¼UNBAL.¼
HIGH
GND
LOW
PIN 2
PIN 3
PIN 1
TIP
RING
SLEEVE
TIP
SLEEVE
GND
Chapter 2 Installation Section 10
DIRECT
OUTPUT
INPUT
MIX LINK
speck
electronics
S/N
230V (.1A)
MIX LEFT
INSERT RTN
PRE OUT-B
INSERT SEND
LINE IN
AUX DC OUT
CAUTION
MicPre 5.0
115V (.2A)
MIX RIGHT
O.S.P.
OR
RISK OF ELECTRICAL SHOCK - DO NOT
OPEN OR EXPOSE TO RAIN OR MOISTURE.
NORMAL
Do not connect
the ASC
power module ASC-DCI cable

With only a simple connection, the mix sections of two MP 5.0's can be
summed together and operate like a multichannel mixer.
To link two MP 5.0's, an optional MP50-LINK2 mix link cable is
required. This link cable has RJ-45 modular plugs on both ends. One end
has a "clear" colored plug and the other end has a "red" plug. The MP 5.0
that receives the "red" plug is the unit that will become the master.
The illustration below shows how to link two MP 5.0's.
Linking two MP 5.0's
DIRECT
OUTPUT
INPUT
MIX LINK
speck
electronics
S/N
230V (.1A)
MIX LEFT
INSERT RTN
PRE OUT-B
INSERT SEND
LINE IN
AUX DC OUT
CAUTION
MicPre 5.0
115V (.2A)
MIX RIGHT
O.S.P.
OR
RISK OF ELECTRICAL SHOCK - DO NOT
OPEN OR EXPOSE TO RAIN OR MOISTURE.
NORMAL
DIRECT
OUTPUT
INPUT
MIX LINK
speck
electronics
S/N
230V (.1A)
MIX LEFT
INSERT RTN
PRE OUT-B
INSERT SEND
LINE IN
AUX DC OUT
CAUTION
MicPre 5.0
115V (.2A)
MIX RIGHT
O.S.P.
OR
RISK OF ELECTRICAL SHOCK - DO NOT
OPEN OR EXPOSE TO RAIN OR MOISTURE.
NORMAL
Chapter 2 Installation Section 11
Clear Red
MP50-LINK2 cable
To line inputs on a mixer,
DAT, or A/D converters

With only a simple connection, three or more MP 5.0’s can be summed
together and operate like a multichannel mixer.
To link the MP 5.0's, an optional mix link cable is required. This link
cable has as many as eight RJ-45 modular plugs wired in a "daisy chain"
configuration. All of the plugs are a "clear" color except for a "red"
colored plug at one end. The MP 5.0 that receives the "red" plug is the
unit that will become the master.
The illustration below shows how to link multiple MP 5.0's.
Linking more
than two MP 5.0's
Chapter 2 Installation Section 12
DIRECT
OUTPUT
INPUT
MIX LINK
speck
electronics
S/N
230V (.1A)
MIX LEFT
INSERT RTN
PRE OUT-B
INSERT SEND
LINE IN
AUX DC OUT
CAUTION
MicPre 5.0
115V (.2A)
MIX RIGHT
O.S.P.
OR
RISK OF ELECTRICAL SHOCK - DO NOT
OPEN OR EXPOSE TO RAIN OR MOISTURE.
NORMAL
DIRECT
OUTPUT
INPUT
MIX LINK
speck
electronics
S/N
230V (.1A)
MIX LEFT
INSERT RTN
PRE OUT-B
INSERT SEND
LINE IN
AUX DC OUT
CAUTION
MicPre 5.0
115V (.2A)
MIX RIGHT
O.S.P.
OR
RISK OF ELECTRICAL SHOCK - DO NOT
OPEN OR EXPOSE TO RAIN OR MOISTURE.
NORMAL
DIRECT
OUTPUT
INPUT
MIX LINK
speck
electronics
S/N
230V (.1A)
MIX LEFT
INSERT RTN
PRE OUT-B
INSERT SEND
LINE IN
AUX DC OUT
CAUTION
MicPre 5.0
115V (.2A)
MIX RIGHT
O.S.P.
OR
RISK OF ELECTRICAL SHOCK - DO NOT
OPEN OR EXPOSE TO RAIN OR MOISTURE.
NORMAL
DIRECT
OUTPUT
INPUT
MIX LINK
speck
electronics
S/N
230V (.1A)
MIX LEFT
INSERT RTN
PRE OUT-B
INSERT SEND
LINE IN
AUX DC OUT
CAUTION
MicPre 5.0
115V (.2A)
MIX RIGHT
O.S.P.
OR
RISK OF ELECTRICAL SHOCK - DO NOT
OPEN OR EXPOSE TO RAIN OR MOISTURE.
NORMAL
ClearClear
ClearClear
Clear Red
To additional MP 5.0's
MP50-LINK6 cable
To line inputs on a mixer,
DAT, or A/D converters

With only a simple connection, two MP 5.0’s can be linked together for
M-S (Mid-Side) micing.
To link MP 5.0's for M-S micing, an optional link cable is required. This
link cable has a RJ-45 modular plug on one end, and a TRS ¼" plug at
the other end. The MP 5.0 that receives the RJ-45 modular plug is this
unit that will become the master.
The illustration below shows how to link two MP 5.0's.
Interfacing two MP 5.0's
for M-S operation
Chapter 2 Installation Section 13
DIRECT
OUTPUT
INPUT
MIX LINK
speck
electronics
S/N
230V (.1A)
MIX LEFT
INSERT RTN
PRE OUT-B
INSERT SEND
LINE IN
AUX DC OUT
CAUTION
MicPre 5.0
115V (.2A)
MIX RIGHT
O.S.P.
OR
RISK OF ELECTRICAL SHOCK - DO NOT
OPEN OR EXPOSE TO RAIN OR MOISTURE.
NORMAL
DIRECT
OUTPUT
INPUT
MIX LINK
speck
electronics
S/N
230V (.1A)
MIX LEFT
INSERT RTN
PRE OUT-B
INSERT SEND
LINE IN
AUX DC OUT
CAUTION
MicPre 5.0
115V (.2A)
MIX RIGHT
O.S.P.
OR
RISK OF ELECTRICAL SHOCK - DO NOT
OPEN OR EXPOSE TO RAIN OR MOISTURE.
NORMAL
MP50-MS cable
To line inputs on a mixer,
DAT, or A/D converters
Side Mid

Chapter 2 Installation Section 14
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