Drawmer CPA-50 Operator's Manual

DRAWMER

CPA-50

POWER AMPLIFIER

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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DRAWMER

This manual is copyrighted © 2016 by Dr awmer El ectronics Ltd. W ith all rights rese rved. Under copyright
laws, n o part of this publication m ay be reprod uced, trans mitted, stored i n 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 Ele ctronics Ltd.

ONE YEAR LIMITED WARRANTY

Drawm er Electr onics Lt d., warrant s the Draw mer CPA-50 Power
Amplifier to conform substantially to the specifications of this manual

for a period of one year from the original date of purchas e when used
in accord ance with t he specificatio ns detaile d in this m anual. In the
case of a valid war ranty claim, y our sole and exclusi ve remed y and
Drawmer’s entire liability under any theory of liability will be to, at
Drawme r’s discretion, repair or replace the pr oduct witho ut charge,
or, if not poss ible, to refund the p urchase 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.
Alternat ively call Drawm er Elect ronics Ltd. at [phone].
Then ship the defective prod uct, with trans portation and insuran ce
charges pre-paid, to Drawmer Electronics Ltd., Coleman Street,
Parkga te, Rotherham , S62 6EL UK . Writ e the RA num ber in lar ge
letters in a prominent position on the shipping box. Enclose your
name, address, telephone number, copy of the original sales invoice
and a deta iled descri ption of the pro blem. Drawm er will not accept
responsibility for loss or damage during transit.

This warranty is void if the product has been damaged by misuse,
modif ication, una uthorised repai r or installed with othe r equipment
that proved to be faulty.

THIS WARRANTY IS IN LIEU OF ALL W ARRANTIES, WHETHER
ORAL OR WRITTEN, EXPRESSED, IMPLIED OR STATUTORY.
DRAWMER MAKES NO OTHER WARRANTY EITHER
EXP RESS OR IMPLIE D, INCLU DING, W ITHOUT LIMITATION,
AN Y IMPLI ED W ARR ANTIE S OF ME RCH ANTAB ILITY, FITNE SS
FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
PURCHASER’S SOLE AND EXCLUSIVE REMEDY UNDER THIS
WARRANTY SHALL BE REPAIR OR REPLACEMENT AS
SPECIFIED HEREIN.
IN NO EVENT W ILL DRAWMER ELE CTRONICS LTD. BE LIABLE
FOR ANY DIRECT, INDIRECT, SPECIA L, INCIDENTAL OR
CONSEQUENTIAL DAMAGES RESULTING FROM ANY
DEFECT IN THE PRODUCT, INCLUDING LOST PROFITS,
DAMAGE TO PROPERTY, AND, TO THE EXTENT PERMITTED
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
implied warranties or limitations on how long an implied warranty may
last, so the above limitations may not apply to you. This warranty gives
you specific legal rights. You may have additional rights that vary from
state to sta te, and country to count ry.

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 CONSIDERAT

DO NO T OPEN. REFER ALL SERVICING TO QUA LIFIED SERVICE PERSONNEL.

TO REDUCE RISK OF FIRE/ELECTR IC SHOCK DO NOT EXPOSE THIS EQUIPMENT T O MOISTURE.

DO N OT ATT EMPT TO CHANG E OR TAMPER W ITH THE SUPPLIED MAINS CABLES.

THE FUSE IN THE INLET HAS BEEN SET TO A RATING THAT ENSURES IT WILL BLOW BEFORE THE
INTERNAL FUSE IF T HE AMPLIFIER IS DRIVEN AT CLIPPING LEVELS FOR ANY SIGNIFICANT LENG TH
OF TIME. THIS IS TO PREVENT T HE AMPLIFIER AND/OR SPEAKERS FROM BEING DAMAGED. T O
REDUCE THE R ISK OF FIRE REPLACE THE MAINS FUSES ONLY WITH A FUSE THAT CONFORMS TO
IEC127-2. 250 VOLT W ORKING, TIME DE LAY TYPE AND BODY SIZE OF 20mm x 5m m. T HE MAINS
INPUT FUSE MUST BE RATED AT T800mA at 115V and T500mA at 230V.

2

COPYRIGHT

FEDERAL COMMUNICATIONS COMMISSION RADIO

FREQUENCY INTERFERENCE STATEMENT

This equipment has been tested and f ound to comply with the limits
for a Cl ass B di gital de vice, purs uant to P art 15 of t he FCC Rules .
These lim its are desig ned to provide reasona ble protec tion against
harmful interference in a residential installation. This equipment
generates , uses a nd can radiate radi o frequenc y energy and, if n ot
instal led and used in accord ance with th e instruc tions, m ay cause
harmful i nterference to radio com munications. However, there is no
guarantee th at interference w ill not occ ur in a particul ar installatio n.
If this equipment does cause interference to radio or television
reception, whic h can be determine d by turning the equipme nt off an
on, then th e user is e ncouraged to t ry to correct the interferenc e by
one or mo re of the fol lowing mea sures:

Re-orie nt or reloca te the r eceiving ant enna.

Increase the separation bet ween the equipment and the rec eiver.

Connect the equipment into an outlet on a circuit different from that
to whic h the recei ver is connecte d.

Consult the dealer or an experienced radio/TV t echnician for help.

Unauthorised changes or modification to this system can void the
users’ a uthority to operat e this equipm ent.
This equipment requires shielded interface cables in order to meet
FCC class B limit.

CLASS B NOTICE

This di gital app aratus do es not exceed t he Class B limit s for radio
noise emis sions set out in the Radio Interference Regulations of the
Canadian Department of Communications.

CLASS E 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.

CAUTION - SERVICING

WARNING

WARNING

WARNING

For the USA

For Canada

IONS

CHAPTER 1

CPA-50

Power Amplifier

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.

Drawmer CPA-5 0 Power Amplifier Featu res 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.

CPA-50 Power Amplifier

3

DRAWMER

POWER CONNECTION

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.

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.

4

TYPICAL CONNECTION GUIDE

STANDARD STEREO WIRING

50+50Wrms into 4 Ohms@1%THD

CPA-50 Power Amplifier

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DRAWMER

CONTROL DESCRIPTION

1

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

2

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.

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CHAPTER 2

3

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.

4

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 Europ ean legi slatio n the use of banan a plugs is not perm itted. Bana na plugs s hould only be used

in the USA a nd Canada.

5

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.

CPA-50 Power Amplifier

2

7

DRAWMER

100+100Wrms into 4 Ohms@1%THD

HORIZONTAL BI-AMPING (2 Required)

EXAMPLE WIRING METHODS

STEREO BI-WIRING

50+50Wrms into 4 Ohms@1%THD

8

100+100W rms into 8 Ohms@1%THD

STEREO VIA MONOBLOCKS (2 Required)

VERTICAL BI-AMPING (2 Required)

100+100W rms into 4 Ohms@1%THD

CPA-50 Power Amplifier

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DRAWMER

CHAPTER 3

MPA-90 GENERAL INFORMATION

IF A FAULT DEVELOPS

For warranty service pleas e call Drawmer Electroni cs
Ltd. or their nearest authorised s ervice facility, giving
full details of the difficulty. A list of all main dealers
can be found on the Drawm er webpages. On recei pt
of this information, service or shippi ng instructio ns
will be forwarded to you.
No equipment should be ret urned under the warranty
without prior consent from Dr awmer or their authorised
representative.
For s ervice claims under the warranty agreement a
service Returns Authorisation (RA) number will be
issued.
Wr ite this RA number in large lett ers in a promine nt
position on the shipping box. Enclose your name,
address, telephone number, copy of the original sa les
invoice and a detailed description of the problem.
Authori sed returns should be prepaid and must be
insure d.
All Drawmer products are packaged in specially
designed contai ners for protection. If the unit is to
be returned, the original container must be used. If
this container is not available, then the equipment
shoul d be packaged in s ubstantial shock-pr oof
material, capable of withstanding the handling for
the transit.

CONTACTING DRAWMER

We will be pleased to answer al l 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]
Fa x: [phone]

Contact via E-mail: [e-mail]

Further information on all Drawmer products,
dealers, Authorised s ervice departments and other
contact inform ation can be found on our website:

www.drawmer.com

SPECIFICATION

Note: These specificat ions are provis ional and may alter slightly upon product release.

CPA-50 8ohm CPA-50 4ohm

T HD @ 1 W 0.004 0.004
THD@25W/8Ohms 0.025 N/A
POW ER @ 1% THD 25+25 Wrms 50+50 Wrms
BR ID GE D PO W ER @ 1 % T HD 100Wrms 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

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

10

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 h as been se t to a rating
that ensures it wi ll bl ow before the internal fuse if t he
amplifier is driven at clippi ng levels for any si gnificant
length of time. T his i s to prevent the amplifier and/or
speaker s from being dam aged.

CASE SIZE

184mm(D) x 165mm(W ) x 51mm(H)
WEIGHT 1.25kg

Ref:1v00A 29-06-16

% THD Noise vs Power

CPA-50 Power Amplifier

11

DRAWMER

Drawmer Electronics Ltd, Coleman St, Parkgate,

Rotherham, South Yorkshire, U.K.