Drawmer CPA-50 User manual

DRAWMER
CONTENTS
Warranty
Safety Consideration
Radio Frequencies Statement
Chapter 1 - Introduction
Introduction
Power Connection
Portable Applinace Testing
Typical Connection Guide
Chapter 2 - Control Description
Contol Description
Example Wiring Methods
Chapter 3 - General Information
If a fault develops
Contacting Drawmer
Specification
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CPA-50
POWER AMPLIFIER

2
DRAWMER
COPYRIGHT
This manual is copyrighted © 2016 by Drawmer Electronics Ltd. With all rights reserved. Under copyright
laws, no part of this publication may be reproduced, transmitted, stored in a retrieval system or translated
into any language in any form by any means, mechanical, optical, electronic, recording, or otherwise,
without the written permission of Drawmer Electronics Ltd.
Drawmer Electronics Ltd., warrants the Drawmer CPA-50 Power
Amplifier to conform substantially to the specifications of this manual
for a period of one year from the original date of purchase when used
in accordance with the specifications detailed in this manual. In the
case of a valid warranty claim , your sole and exclusive remedy and
Drawmer’s entire liability under any theory of liability will be to, at
Drawmer’s discretion, repair or replace the product without charge,
or, if not possible, to refund the purchase price to you. This w arranty
is not transferable. It applies only to the original purchaser of the
product.
For warranty service please call your local Drawmer dealer.
Alternatively call Drawmer Electronics Ltd. at [phone].
Then ship the defective product, with transportation and insurance
charges pre-paid, to Drawmer Electronics Ltd., Coleman Street,
Parkgate, Rotherham, S62 6EL UK. Write the RA number in large
letters in a prominent position on the shipping box. Enclose your
name, address, telephone number, copyof the original sales invoice
and a detailed description of the problem. Drawmer will not accept
responsibility for loss or damage during transit.
This warranty is void if the product has been damaged by misuse,
modification, unauthorised repair or installed with other equipment
that proved to be faulty.
THIS WARRANTY IS IN LIEU OF ALL W ARRANTIES, W HETHER
ORALOR WRITTEN, EXPRESSED, IMPLIED ORSTATUTORY.
DRAWMER MAKES NO OTHER WARRANTY EITHER
EXPRESS OR IMPLIED, INCLUDING, W ITHOUT LIMITATION,
ANY IMP LIED W ARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
PURCHASER’S SOLE ANDEXCLUSIVE REMEDY UNDER THIS
WARRANTY SHALL BE REPAIR OR REPLACEMENT AS
SPECIFIED HEREIN.
IN NO EVENT W ILL DRAWMER ELECTRONICS LTD. BE LIABLE
FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR
CONSEQUENTIAL DAMAGES RESULTING FROM ANY
DEFECT IN THE PRODUCT, INCLUDING LOST PROFITS,
DAMAGE TO PROPERTY,AND, TO THE EXTENTPERMITTED
BY LAW, DAMAGE FOR PERSONAL INJURY, EVEN IF
DRAWMER HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.
Some states and specific countries do not allow the exclusion of
impliedwarranties or limitations on how long an implied warrantymay
last, so the above limitations may not apply toyou. This warranty gives
you specific legal rights. You may have additional rights that vary from
state to state, and country to country.
For the USA
FEDERAL COMMUNICATIONS COMMISSION RADIO
FREQUENCY INTERFERENCE STATEMENT
This equipment has been tested and found to com ply with the limits
for a Class B digital device, pursuant to Part 15 of the FCC Rules.
These lim its are designed to provide reasonable protection against
harmful interference in a residential installation. This equipment
generates, uses and can radiate radio frequencyenergy and, if not
installed and used in accordance with the instructions, may cause
harmful interference to radio communications. However, there is no
guarantee that interference will not occur in a particular installation.
If this equipment does cause interference to radio or television
reception, which can be determined by turning the equipment off an
on, then the user is encouraged to try to correct the interference by
one or more of the following measures:
Re-orient or relocate the receiving antenna.
Increase the separation between the equipment and the receiver.
Connect the equipment into an outlet on a circuit different from that
to which the receiver is connected.
Consult the dealer or an experienced radio/TV technician for help.
Unauthorised changes or modification to this system can void the
users’ authority to operate this equipment.
This equipment requires shielded interface cablesin order to meet
FCC class B limit.
For Canada
CLASS B NOTICE
This digital apparatus does not exceed the Class B limits for radio
noise emissions set out in the Radio Interference Regulations of the
Canadian Department of Communications.
CLASSE B AVIS
Cet appareil numérique ne dépasse pas les limites de la classe B au
niveau des émissions de bruits radioélectriques fixés dans le
Règlement des signaux parasites par le ministère Canadien des
Communications.
In the interests of product development, Drawmer reserve the right to modify
or improve specifications of this product at any time, without prior notice.
SAFETY CONSIDERATIONS
CAUTION - SERVICING
DO NOT OPEN. REFER ALL SERVICING TO QUALIFIED SERVICE PERSONNEL.
WARNING
TO REDUCE RISK OF FIRE/ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO MOISTURE.
WARNING
DO NOT ATTEMPT TO CHANGE OR TAMPER W ITH THE SUPPLIED MAINS CABLES.
WARNING
THE FUSE IN THE INLET HAS BEEN SET TO A RATING THAT ENSURES IT WILL BLOW BEFORE THE
INTERNAL FUSE IF THE AMPLIFIER IS DRIVEN AT CLIPPING LEVELS FOR ANY SIGNIFICANT LENGTH
OF TIME. THIS IS TO PREVENT THE AMPLIFIER AND/OR SPEAKERS FROM BEING DAMAGED. TO
REDUCE THE RISK OF FIRE REPLACE THE MAINS FUSES ONLY WITH A FUSE THAT CONFORMS TO
IEC127-2. 250 VOLT WORKING, TIME DELAY TYPE AND BODY SIZE OF 20mm x 5mm. THE MAINS
INPUT FUSE MUST BE RATED AT T800mA at 115V and T500mA at 230V.
ONE YEAR LIMITED WARRANTY

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CPA-50 Power Amplifier
CHAPTER 1
The CPA-50 Stereo Power Amp is the
perfect partner for any passive speaker,
and especially in the studio with a set of
passive cube monitors.
Sitting between your monitor controller/
pre-amp and a pair of passive speakers,
the high performance Class D amplifier
delivers 25Wrms per channel into 8 ohms
(50Wrms per channel into 4ohms) and
offers features including thermal, overload
and power up/power down protection and fault indication. With just a 6.5” square
footprint, the CPA-50 blends seamlessly with a pair of Yamaha NS10 or Auratone
C5 monitor types, for example, and is small and light enough to fit into a bag to take
anywhere.
As well as working in stereo the CPA-50 can also function as a 100Wrms into
8ohms Monoblock (set via internal jumpers), which allows the system to operate
in bi-amped or bridged modes.
CPA-50
Power Amplifier
Drawmer CPA-50 Power Amplifier Features at a Glance:
50+50Wrms into 4 Ohms@1%THD.
25+25Wrms into 8 Ohms@1%THD.
1x100W into 8 Ohms bridged mode.
Stereo/Bridge internal jumper to use
as a Stereo amplifier or as a
Monoblock in Bridged or Bi-Amp
Modes.
Balanced Neutrik XLR input.
Efficient, low heat design with Low Power Consumption. Consumes
only 6W of power when idling and <0.5W when in standby mode.
Thermal, overload and power up/power down protection.
Standby, fault and clip indicators
Rugged steel chassis. Desktop unit that can be stacked.
Compact and Portable. Dimensions: L 184mm x W 165mm x H 51mm.

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DRAWMER
The CPA-50 unit will be supplied with a power cable suitable for domestic power
outlets in your country. For your own safety, it is important that you use this cable to
connect to the mains supply earth. The cable must not be tampered with or modified.
The power supply socket has an integral fuse drawer containing the power fuse of
the same value, to suit the mains voltage for which the unit has been supplied.
Removal of the drawer is only possible with the power cord removed. The fuse
should never blow under normal operation. If the fuse is suspected of having blown,
then a fault will have occurred and this fault condition should be inspected by a
qualified service engineer. When replacing the fuse, always comply with the Safety
Instructions.
If the unit is to be used with a mains input
operating voltage different to that for which
the unit is supplied, the following
procedure must be carried out by a
technically competent person:
1: Disconnect the unit from the mains
and cable.
2: Using a No.1 size pozidrive
screwdriver, remove the four screws
that retain the top cover.
For conversion to 230Volt AC
(previously set to 115Volt AC).....
3a. remove the jumper across the
CON101 socket
3b. Exchange the T800mA fuse below
the mains socket for a similar type
rated at T500mA
For conversion to 115Volt AC
(previously set to 230Volt AC).....
4a. Add a jumper across the CON101 socket
4b. Exchange the T500mA fuse below the mains
socket for a similar type rated at T800mA
In all cases:
5: Replace the top cover using the four screws.
6: Re-connect to mains power source.
POWER CONNECTION
PORTABLE APPLIANCE TESTING
To undergo a Portable Appliance Testing procedure (commonly known as "PAT",
"PAT Inspection" or "PAT Testing") remove the screw on the right side of the CPA-50,
nearest the IEC socket that holds the cover in place and probe in this cavity.
Alternatively, the screw can be replaced for something more suited to the job, such
as a spade terminal with a self tapping M3 thread.

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CPA-50 Power Amplifier
TYPICAL CONNECTION GUIDE
STANDARD STEREO WIRING
50+50Wrms into 4 Ohms@1%THD

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DRAWMER
CONTROL DESCRIPTION
POWER On / Standby
The unit has a soft on/off switch on the front panel. With the switch in the CPA-50 is
active and the LED indication beneath lights. With the switch out it is operating in
standby - the standby LED illuminates and the CPA-50 draws 0.5 Watts of power.
STATUS Fault
Fault: This is illuminated is the MPA has detected an error via it’s in built sensors,
these include:
Power shut down by over temperature - If the temperature inside the MPA should
pass the threshold of 100°C minimum to 110°C maximum (105°C typical) the MPA
will shut down for a few moments. The shutdown time is short but increases as the
unit heats up. As well as the illumination of the LED indication this protection mode
will be heard as very short interrupts to the sound.
Over voltage shutdown. - If the mains voltage exceeds the absolute maximum
rated level of ~ 90-132 / 180-264 VAC the MPA will momentarily shut down and the
Fault LED will illuminate. This protection mode will be heard as very short interrupts
to the sound. In the event of a fault occurring the source of the problem should be
repaired before permanent damage to the system occurs.
Bridge:
To set Bridge mode, to use the
CPA-50 as a monoblock, remove
the cover by unscrewing the four
screws. Set the jumpers on
connectors J7 and J10 to the
position shown in the diagram
(right). Replace the cover.
Note: Use only the left input, and
connect to R-and L+speaker
terminals (R+ & L- are not used).
The Bridge LED will be inactive in
stereo mode, providing
50+50Wrms into 4 Ohms. When
the Bridge LED is illuminated it
indicates that the CPA-50 is set to
Bridge (mono) mode, providing
1x100Wrms into 8 Ohms.
1
2

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CPA-50 Power Amplifier
BALANCED INPUT XLR
The input is in the form of Balanced Neutrik XLR connectors
• Interference:
If the unit is to be used where it maybe exposed to high
levels of disturbance such as found close to a TV or radio
transmitter, we advise that the unit is operated in a
balanced configuration. The screens of the signal cables
should be connected to the chassis connection on the
XLR connector as opposed to connecting to pin1. The
CPA-50 conforms to the EMC standards.
• Ground Loops:
If ground loop problems are encountered, never disconnect the mains earth,
but instead, try disconnecting the signal screen on one end of each of the
cables connecting the outputs of the CPA-50 to the patchbay. If such measures
are necessary, balanced operation is recommended.
SPEAKER OUTPUTS L-/L+/R-/R+
The speaker outputs connectors are in the form of binding posts that can be wired
directly to the speaker terminals via bare wires through the hole and tightened, via
spade terminals, or via banana plugs.*
The diagrams on the following pages show some common wiring methods. Note
that when in bridged mono mode the R-provides the negative terminal and L+
provides the positive, the other terminals are not used. (See Bridge)
*Due to European legislation the use of banana plugs is not permitted. Banana plugs should only be used
in the USA and Canada.
POWER
The mains inlet, I.E.C., which also incorporates the internal mains fuse, can be
found on the rear of the unit. If a fuse should need replacing see section ‘Power
Connection’. A mains lead will have been provided with the CPA-50 to suit the
mains configuration for the country of your purchase. Please use this cable.
The power switch is a hard boot switch (as opposed to a soft stand-by switch) and
so when in the off position the CPA-50 will draw no mains power.
CHAPTER 2
3
2
4
5

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DRAWMER
STEREO BI-WIRING
50+50Wrms into 4 Ohms@1%THD
HORIZONTAL BI-AMPING (2 Required)
100+100Wrms into 4 Ohms@1%THD
EXAMPLE WIRING METHODS

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CPA-50 Power Amplifier
VERTICAL BI-AMPING (2 Required)
100+100Wrms into 4 Ohms@1%THD
STEREO VIA MONOBLOCKS (2 Required)
100+100Wrms into 8 Ohms@1%THD

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DRAWMER CHAPTER 3
CPA-50 8ohm CPA-50 4ohm
T HD @ 1 W 0.004 0.004
THD@25W/8Ohms 0.025 N/A
POWER @ 1% THD 25+25 Wrms 50+50 Wrms
BR IDGE D PO W ER @ 1% T H D 100W rms N/A
GAIN 25.7dB 25.7dB
Balanced CROSSTALK @ 0dBu 1kHz <85dB <85dB
Input voltage for max unclipped output 775mv (0dBu) 775mv (0dBu)
Frequency Response (+/-0.25dBu ) 20Hz-20kHz 20Hz-20kHz
Output Impedance 6milli ohms 6milli ohms
For warranty service please call Drawmer Electronics
Ltd. or their nearest authorised service facility, giving
full details of the difficulty. A list of all main dealers
can be found on the Drawmer webpages. On receipt
of this information, service or shipping instructions
will be forwarded to you.
No equipment should be returned under the warranty
without prior consent from Drawmer or their authorised
representative.
For service claims under the warranty agreement a
service Returns Authorisation (RA) number will be
issued.
Write this RA number in large letters in a prominent
position on the shipping box. Enclose your name,
address, telephone number, copy of the original sales
invoice and a detailed description of the problem.
Authorised returns should be prepaid and must be
insured.
All Drawmer products are packaged in specially
designed containers for protection. If the unit is to
be returned, the original container must be used. If
this container is not available, then the equipment
should be packaged in substantial shock-proof
material, capable of withstanding the handling for
the transit.
CONTACTING DRAWMER
We will be pleased to answer all application questions
to enhance your usage of Drawmer equipment.
Please address correspondence to:
DRAWMER Electronics LTD
Coleman Street
Parkgate
Rotherham
South Yorkshire
S62 6EL
United Kingdom
Telephone: [phone]
Fax: [phone]
Contact via E-mail: [e-mail]
Further information on all Drawmer products,
dealers, Authorised service departments and other
contact information can be found on our website:
www.drawmer.com
MPA-90 GENERAL INFORMATION
IF A FAULT DEVELOPS
POWER REQUIREMENTS
Nominal rating: ~ 115 / 230 VAC
Absolute min/max:~ 90-132 / 180-264 VAC
45-63Hz
POWER CONSUMPTION
@ Idle 6W typ. 8W max at 230VAC
@ Standby <500mW typical
SPECIFICATION
Note: These specifications are provisional and may alter slightly upon product release.
FUSE
20mm x 5mm, Class 3 Slo-Blo,
250Volt working. Conforming to IEC 127-2
@ 115V T800mA
@ 230V T500mA
Note: the fuse in the inlet has been set to a rating
that ensures it will blow before the internal fuse if the
amplifier is driven at clipping levels for any significant
length of time. This is to prevent the amplifier and/or
speakers from being damaged.
CASE SIZE
184mm(D) x 165mm(W ) x 51mm(H)
WEIGHT 1.25kg
Ref:1v00A 29-06-16

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CPA-50 Power Amplifier
% THD Noise vs Power

Drawmer Electronics Ltd, Coleman St, Parkgate,
Rotherham, South Yorkshire, U.K.
DRAWMER