Page 1
Amplifiers
User Manual: CA2 Preamplifier
SCA2 Preamplifier
SIA2-150 Integrated Amplifier
SPA2-150 Power Amplifier
SPA2-200P Power Amplifier
MULTICHANNEL
ACOUSTICENGINEERS
®
Page 2
Electronics
1. Read instructions – all the safety and operating instructions should be read
before the appliance is operated.
2. Retain these instructions – the safety and operating instructions should be
retained for future reference.
3. Heed warnings – all warnings on the appliance and in the operating
instructions should be adhered to.
4. Follow instructions – all operating and other instructions should be
followed.
5. Water and moisture – the appliance should not be used near water, for
example near a bathtub, washbowl, kitchen sink, laundry tub, in a wet
basement or near a swimming pool etc..
6. Ventilation – the appliance should be situated so that its location or
position does not interfere with its proper ventilation. For example, the
appliance should not be situated on a bed, sofa, rug or similar surface that
may block the ventilation openings. Similarly, the appliance should not be
built into an installation, such as a bookcase or cabinet, that may impede
the flow of air through the ventilation openings.
7. Heat – the appliance should be situated away from heat sources such as
radiators, stoves or other appliances that produce heat.
8. Power sources – the appliance should be connected to a power supply only
of the type described in the operating instructions or as marked on the
appliance.
9. Power cord protection – power supply cords should be routed 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 the appliance.
10. Cleaning – the appliance should be cleaned only as recommended by the
manufacturer.
11. Unattended periods – the power cord of the appliance should be
unplugged from the outlet when left unused for a long period of time.
12. Object and liquid entry – care should be taken so that objects and liquids
do not fall into the appliance.
13. Damage requiring service – the appliance should be serviced by qualified
service personnel when:
i. the power supply cord or the plug has been damaged
ii. objects have fallen or liquid has been spilled into the appliance
iii. the appliance has been exposed to rain or other serious liquid exposure
iv. the appliance does not appear to operate normally or exhibits a marked
change in performance
v. the appliance has been dropped or the cabinet damaged
14. Servicing – the user should not attempt to service the appliance beyond
those measures described in the operating instructions.All other servicing
should be referred to qualified service personnel.
15. Grounding or polarisation – precautions should be taken so that grounding
or polarisation means for the appliance are not defeated.
1
Safety Warnings
Page 3
Electronics
Welcome. In selecting ATC you have chosen an example of the finest audio
engineering available. ATC was founded on a principle of engineering
excellence, and that principle still defines our products today. Given the right
opportunities, ATC products will deliver exceptional audio performance, but
the opportunities will only arise from careful and thoughtful installation and
use. Please read the following manual fully. It will help you understand the
product and to realise its full potential.We are happy to answer questions and
offer advice on any issues that arise through installation or use of ATC
products. Contact details can be found at the back of this manual.
ATC was founded in London in 1974 by Australian emigre Bill Woodman, who still
heads the company today. An enthusiastic pianist and engineer he was naturally
drawn to loudspeaker design and after a period working at Goodmans,where many
of the names that went on to found British loudspeaker companies began their
careers, he struck out on his own.The premise on which ATC began is a simple one,
and one that in many respects is still true today: hi-fi loudspeakers tend to be
detailed and accurate but of limited dynamic range, while professional monitor
speakers tend to express the opposite character. ATC products were designed from
the outset to offer the best of both. It’s an easy concept to describe, but surprisingly
difficult to engineer.
The difficulty inherent in designing such loudspeakers is one of scale. Hi-fi levels of
accuracy and detail call for lightweight moving parts and delicate engineering.
Professional monitor levels of performance however demand far more robust
components engineered to survive the rigours of high level use for extended
periods.The only way to combine the two is through precision engineering of a class
and scale more often associated with aerospace or motorsport. But the results are
worth the effort and the cost. ATC loudspeakers, with their unique in-house
designed drivers, combine the best of hi-fi and professional to devastating effect.
ATC has become synonymous with active systems. Choosing to offer active
loudspeakers (where the passive crossover network is replaced by active filters and
multiple power amplifiers) is simply a result of the uncompromising attitude to
loudspeaker design.While passive systems still have their place,and ATC engineering
skills can still bring remarkable results from them,“active” is a fundamentally better
solution to the problems posed by accurate, high level music reproduction.The ATC
instinct is always for the better solution. Not cheaper, not quicker, but better.
It was the development of active loudspeakers that first brought ATC into
electronics design and engineering. Active speakers demand multiple power
amplifiers so ATC from the mid 1980s became not just a loudspeaker manufacturing
company but an electronics manufacturer too.The further step from electronics for
active speakers to a range of stand-alone amplifier products was natural and now
means that ATC engineering is available from the recording desk or CD player
output to the ears.
From modest beginnings ATC has grown to become one of the very few
manufacturers successful across both domestic and professional audio. By selecting
ATC you join a group of music lovers, professional audio engineers, studios and
musicians across the World that understand and value the engineering that goes into
an ATC product - and the sound that comes out.
Introduction
2
Contents
Page 2 Introduction
Page 3 CA2 Preamplifier
Section 1.1 Description
Section 1.2 Installation
Section 1.3 Mains Connection
Page 4 Section 1.4 Inputs
Page 5 Section 1.5 Outputs
Section 1.6 Operation
Page 6 Section 1.7 Remote Handset
Section 1.8 Care and Maintenance
Section 1.9 Warranty and Contact
Specifications
Page 7 SCA2 Preamplifier
Section 2.1 Description
Section 2.2 Installation
Section 2.3 Mains Connection
Page 8 Section 2.4 Inputs
Page 9 Section 2.5 Outputs
Section 2.6 Operation
Page 10 Section 2.7 Remote Handset
Page 11 Section 2.8 Care and Maintenance
Section 2.9 Warranty and Contact
Specifications
Page 12 SIA2-150 Integrated Amplifier
Section 3.1 Description
Section 3.2 Installation
Section 3.3 Mains Connection
Section 3.4 Inputs
Page 13 Section 3.5 Outputs
Section 3.6 Operation
Section 3.7 Remote Handset
Page 14 Section 3.8 Care and Maintenance
Section 3.9 Warranty and Contact
Specifications
Page 15 SPA2-150 & SPA2-200P
Power Amplifiers
Section 4.1 Description
Section 4.2 Installation
Section 4.3 Mains Connection
Section 4.4 Inputs
Page 16 Section 4.5 Signal Cable Options
Section 4.6 Outputs
Section 4.7 Operation
Page 17 Section 4.8 Remote Operation
Page 18 Section 4.9 Care and Maintenance
Section 4.10 Warranty and Contact
Specifications
Page 4
CA2
1.1 Description
The CA2 preamplifier is designed to partner ATC active, and with an appropriate
power amplifier, passive loudspeaker systems. It incorporates six line-level stereo
inputs and one stereo record output on RCA phono sockets, and a main stereo
output on XLR sockets.
The AUX 2 line-level input may be converted to function as a high-sensitivity phono
input through the addition of a factory fitted optional RIAA Phono Board.The RIAA
board carries an array of slide switches that enable optimal matching with phono
cartridges of various output voltages and loading requirements.
Selection of CA2 inputs is achieved via a five-position rotary control using gold plated
relays for silent switching. Output volume adjustment is achieved through a precision
motorised potentiometer.A tape monitor function can be selected from a front panel
push button.The tape output is a duplicate of the signal selected by the input selector.
Mute and standby functions are also accessible from front panel push buttons. Mains
power is applied from a rear panel mounted switch. A rear panel mounted 1/4 inch
stereo headphone socket can be used with or without the main speakers in use.
All CA2 functions are duplicated on the ATC SCAR-B remote control handset.
1.2 Installation
The CA2 is designed to be free standing either within an equipment stand or simply
on a convenient item of furniture. There are no special ventilation requirements,
however it is recommended that at least 100 mm (4 inches) clearance is left behind
the unit for plugs and cables.
The CA2 is designed to remained powered-up in Standby mode unless it is to be
unused for a long period of time. The power dissipation of the CA2, in either
standby or operational mode, will make it warm to the touch. Temperature stability
will be reached after approximately three hours from mains switch-on. Full audio
performance is however available immediately.
The CA2 should be located so as to minimise the cable length from the source
components.The preamplifier output can effectively drive up to 50m of good quality
cable so it is practical therefore to locate the CA2 a distance away from the
monitors or power amplifier(s).
3
Preamplifier
1.3 Mains Connection
The CA2 can be used with mains voltages from
100V to 240V, 50/60Hz. Ensure that the local
mains voltage matches that uppermost on the rear
panel voltage selector plate before applying mains
power to the CA2.The mains voltage selection can
be adjusted by lifting the selector plate marked
with the four legends (100, 120, 220, 230) with a
small screwdriver and re-inserting the plate with
the correct voltage uppermost.
The mains cable is specifically supplied to comply
with local statutory safety approvals and
alternatives should not be substituted. If you
intend to use your CA2 in an alternative territory
please contact ATC for advice. If an alternative
mains plug is required it must be connected with
the BROWN cable to LIVE, BLUE cable to
NEUTRAL and GREEN/YELLOW cable to
EARTH. On no account should the CA2 mains
cable be connected without an effective mains
earth.
A power supply fuse is fitted within the CA2 but
it is not intended to be user replaceable. If you
suspect that the power supply fuse has failed the
CA2 should be returned to ATC or the local
representative for service. For 230/240V
operation a 3A fuse should be fitted to the mains
plug.
The CA2 preamplifier has been designed to partner ATC active, and with an
appropriate power amplifier, passive loudspeaker systems. It incorporates six line-
level stereo inputs and one stereo record output on RCA phono sockets, a main
stereo output on RCA phono sockets,a main stereo output on XLR sockets, a mono
sub output on RCA phono sockets,and a headphone output on a _” jack socket.
The Aux 2 line-level input may be converted to function as a high-sensitivity phono
input through the addition of a factory fitted optional RIAA Phono Board.The RIAA
board carries an array of slide switches that enable optimal matching with phono
cartridges of various output voltages and loading requirements.
Selection of CA2 inputs is achieved via a five-position rotary control using gold plated
relays for silent switching. Output volume adjustment is achieved through a precision
motorized potentiometer. A tape monitor function can be selected from a front
panel push button; the tape output is a duplicate of the signal selected by the input
selector. Standby is also accessible from a front panel push button. Mains power is
applied from a rear panel mounted switch.
All CA2 functions are duplicated on the ATC SCAR-B remote handset.
Page 5
1.4 Inputs
The CA2 accepts unbalanced RCA Phono style
inputs sockets.The signal is present on the centre
conductor of an unbalanced input and the signal
return is made via the screened outer. If there is
any hum present on the inputs this must be traced
to its source and not suppressed by the removal of
screens or earths. Removal of the screen on an
unbalanced input is likely to result in uncontrollably
loud hum. The input sockets are illustrated in
Diagram 1.
All inputs are line-level sensitivity via RCA phono
connectors on the rear panel. Inputs are labelled
for CD,TUNER,AV, AUX1 or AUX2 however they
are electrically identical and a line level signal from
any source equipment type may be connected to
any input.
The right-hand (viewed from the rear) pair of AUX
2 input sockets will function as a high-sensitivity
phono input if the optional RIAA Vinyl Board is
installed. The RIAA circuitry can be configured to
accommodate a wide selection of phono cartridge
types by setting combinations of the board
mounted jumpers (links). Access to the board is
gained by removing the top panel of the
preamplifier. Diagram 2 illustrates the position of
the jumpers on the board while Table A details the
cartridge matching options available.
Links are moved by pulling them gently away from
the board with a small pair of pliers and are
replaced in the appropriate positions as shown in
the diagrams. Unused links can be “parked” on the
board by setting them at right angles on unused
pins.
Jumpers J3 and J4 set the input load for each channel of the cartridge. With the
jumpers in place the load is 100 ohms.With the jumpers removed the load is 47
kilohms.
Jumpers J1, J2, J5 and J6 set the gain (sensitivity) of the RIAA input. J1 and J2 have
two positions A and B. In position A the gain of the RIAA circuit is reduced, in
position B the gain is increased. J5 and J6 can have the jumper fitted or removed.
When fitted the gain of the circuit is increased. By setting combinations of these 4
jumpers a range of sensitivities can be accommodated.
For example: for a cartridge with a low sensitivity, J1 and J2 would be set in position
B while J5 and J6 would both have their jumper fitted.Table A illustrates the input
sensitivity and load characteristics available.The manufacturer of the cartridge in use
should be able to recommend the appropriate settings.
The left-hand AUX 2 input sockets must not be used when the Phono Board is
installed.
Installation
4
CA2
Diagram 2 - RIAA Phono Board and Jumpers
Table A - RIAA Jumper Settings
J5 J3 J1
Pos A
Pos B
J6 J4 J2
Jumper settings for 1 Volt Output
Sensitivity J1 and J2 J3 and J4 J5 and J6
10.0mV Position A Fitted (100Ω) Removed
6.7mV Position A Removed (47kΩ) Removed
5.1mV Position B Fitted (100Ω) Removed
3.4mV Position B Removed (47kΩ) Removed
2.2mV Position A Fitted (100Ω) Fitted
1.4mV Position A Removed (47kΩ) Fitted
1.1mV Position B Fitted (100Ω) Fitted
0.7mV Position B Removed (47kΩ) Fitted
Pos A
Pos B
Diagram 1 - CA2 rear panel and connection sockets
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5
1.5 Outputs
The CA2 rear panel, illustrated in Diagram 1, carries sockets
for main left and right output, tape left and right output and
stereo headphones. Use of the headphone jack leaves the main
outputs unaffected.The front panel mute function, which does
not affect the headphone output, may be used to suppress the
main outputs when headphones are in use.
Connections to the main output XLR sockets follow the
convention of pin 1 to ground, pin 2 to signal “hot” and pin 3
to signal return (signal ground). When connecting to
equipment with XLR (balanced) inputs the connectors should
be wired pin for pin (ie. 1 to 1, 2 to 2 and 3 to 3). For RCA
(phono) unbalanced connection the “hot” and signal return
(pins 1 and 3) should be joined at the RCA plug. Diagram 3
illustrates the XLR output pin arrangement. Diagram 4
illustrates the cable arrangement for connection to balanced
inputs. Diagram 5 illustrates the cable arrangement for
connection to unbalanced inputs.
Cables up to 50 metres in length may be connected to the
main balanced outputs.
1.6 Operation
Once connected to mains power and powered-up from the
rear panel mains switch, the front panel Standby button (or
remote handset Standby button) will switch the CA2 between
standby and active modes. In Standby mode the Standby
indicator glows RED. Operating the Standby function from
either the front panel or remote handset will switch the CA2
into active mode. The RED indicator will extinguish and be replaced by the Input
Select indicator showing the current selection in GREEN. Operating the Standby
function again will return the CA2 to Standby mode.
Inputs are selected by rotating the input select control in either direction. The
control has continuous movement. When it is moved to the last input, further
rotation will select the first input.
Diagram 6 - CA2 front panel and controls
CA2
Preamplifier
Diagram 3 - output socket pins
Pin 1, ScreenPin 2, Signal (hot)
Pin 3, Signal (return)
Diagram 4 - balanced cable
Diagram 5 - unbalanced cable
Two Core Screened Cable
3 Pin Male XLR
Connector
3 Pin Female XLR
Connector
To Preamp Output
Hot
Return
Screen
To Power Amp or
Monitor Input
1
2
3
1
2
3
Two Core Screened Cable
3 Pin Male XLR
Connector
Phono (RCA)
Connector
To Preamp Output
Hot
Return
Screen
To Power Amp or
Monitor Input
1
2
3
The CA2 rear panel, illustrated in Diagram 1, carries sockets
for main left and right output; tape left and right output, left and
right summed mono output and an output for stereo
headphones. Use of the headphone jack will mute the output
from the main stereo output and also the sub output.
Connections to the main output may be from RCA phono
sockets or XLR sockets. Connections to the XLR output
sockets follow the convention of pin 1 to ground, pin 2 to signal
“hot” and pin 3 to signal return (signal ground). When
connecting to equipment with XLR (balanced) inputs the
connectors should be wired pin for pin (i.e. 1 to 1, 2 to 2 and
3 to 3). Diagram 3 illustrates the XLR output pin arrangement.
Diagram 4 illustrates the cable arrangement for connection to
balanced inputs.
Cables up to 50 metres in length may be connected to the main
stereo or sub outputs.
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6
requirement for any kind of routine service work and there is no schedule for
preventative maintenance.
There are no user replaceable parts within the unit and in the unfortunate event of
any malfunction, repair should be referred to either the supplying dealer or
consultant, the relevant distributor, or ATC.
1.9 Warranty and Contact
All ATC products are guaranteed against any defect in materials or workmanship for
a period of two years from the date of purchase.Within this period we will supply
replacement parts free of charge provided that the failure was not caused by misuse,
accident or negligence.
Purchasers who complete and return the Warranty Card will have their
warranty period extended up to a period of six years from the date of
purchase.This guarantee does not limit statutory rights.
ATC can be contacted at:
Loudspeaker Technology Ltd, Gypsy Lane, Aston
Down, Stroud, Gloucestershire GL6 8HR, UK.
Telephone: 01285 760561
Fax: 01285 760683
Email: info@atc.gb.net
Website: www.atc.gb.net
CA2
Specifications
ATC reserves the right to vary products and specifications without prior notice. Acoustic Transducer Co. is a trading name and ATC
is the registered trade mark of Loudspeaker Technology Ltd.
Main Output Level 7.5V RMS into 600 Ohms
Input Sensitivity 150mV for 1V out at full gain
Input Impedance 5k Ohms
Output Impedance 10 Ohms
Amplitude Response DC - 200kHz ±0.1dB
Total Harmonic Distortion
<
-110dB
Crosstalk -98dB at 10kHz
Power Requirements: 100, 115,230V, 50/60Hz
Power Consumption 35 VA (maximum)
Tape Output Direct
Main Output Connector Balanced Male XLR
Dimensions (HxWxD) 80 x 320 x 280mm
Overall Weight 6.8kg (15lb)
Finish Black and clear anodised aluminium
Operation cont’d
CA2
A separate tape loop is included with a Monitor
option selected by a single push button on the
front panel. The tape output will have the same
signal as selected by the rotary input select
control. Operation of the Standby or tape monitor
controls will not affect this output providing mains
power is maintained.
Output level is controlled by the rotary Volume
control on the front of the unit, the position of
which is indicated by a small gold pin. Rotating the
control clockwise will increase the output level. It
is good practice to lower the volume setting
before switching on the preamplifier or any
associated equipment, or while changing the input
selection.
Due to the nature of the electronics in ATC
amplifiers it is quite normal for a sound to be
heard from the speaker when the power is applied
or disconnected.The noise heard will not damage
the speaker and is quite normal. Although ATC
uses the highest-grade components, a different
noise may be heard from each speaker due to
slight tolarance variations in the amplifier
components.
1.7 Remote Handset
Included with the CA2 is the ATC SCAR-B
remote control handset.This provides for remote
operation of all the CA2 functions and includes a
standard set of CD transport commands which
may be used to control any CD or DVD / SACD
player that supports the RC5 control code set.
Power is supplied by 4 x AAA batteries (included).
1.8 Care and Maintenance
High technology material finishes are used in this
product.The surfaces are durable and with a little
care can be kept as good as new even under
conditions of heavy use. Normally a dry duster will
be all that is required to keep the finishes clean.
Heavy soiling can be cleaned using a cloth slightly
moistened with a non-abrasive household cleaner.
There are no components within the CA2 that
can be considered expendable, or that would
benefit from regular maintenance. There is no
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7
SCA2
2.1 Description
The SCA2 is an extremely high resolution preamplifier designed to partner ATC
active, and, with an appropriate power amplifier, passive loudspeaker systems. It
incorporates eight line-level stereo inputs,two stereo signal outputs and two stereo
record outputs.Two of the line inputs are balanced format on XLR sockets while the
remaining inputs are unbalanced and on pairs of RCA phono sockets.The main
stereo output is balanced format on a pair of XLR sockets while the auxiliary stereo
output is unbalanced and on a pair of RCA phono sockets.The two record outputs
are unbalanced on pairs of RCA phono sockets.
The AUX 2 line-level input may be converted to function as a high-sensitivity phono
input through the addition of a factory fitted optional RIAA Phono Board.The RIAA
board carries an array of slide switches that enable optimal matching with phono
cartridges of various output voltages and loading requirements.
Selection of SCA2 inputs is achieved via a eight-position rotary control using gold
plated relays for silent switching. The SCA2 incorporates an independent record
output signal path so enabling simultaneous listening and recording of different source
signals. Selection of the record output signal is achieved via a second eight-position
rotary control using gold plated relays for silent switching.
Output volume adjustment is achieved through a precision motorised potentiometer.
Mute, gain and standby functions are also accessible from font panel push buttons.
Mains power is applied from a rear panel mounted switch.
All SCA2 functions are duplicated on the ATC SCA-Remote control handset.
2.2 Installation
The SCA2 is designed to be free standing either within an equipment stand or
simply on a convenient item of furniture. It is important however that the support
surface for the SCA2 is solid and free from vibration.There are no special ventilation
requirements for the SCA2, however it is recommended that at least 100 mm (4
inches) clearance is left behind the unit for plugs and cables.
The SCA2 is designed to remained powered-up in Standby mode unless it is to be
unused for a long period of time. The power dissipation of the SCA2, in either
standby or operational mode, will make it warm to the touch. Temperature stability
will be reached after approximately three hours from mains switch-on. Full audio
performance is however available immediately.The SCA2 should be protected from
excessive heat, and must not be allowed to come into contact with any liquid.
The SCA2 should be located so as to minimise the cable length from the source
components.The preamplifier output can effectively drive up to 50m of good quality
cable so it is practical therefore to locate the SCA2 a distance away from the
monitors or power amplifier(s).
Preamplifier
2.3 Mains Connection
The SCA2 can be used with mains voltages from
100V to 240V, 50/60Hz. Ensure that the local
mains voltage matches that uppermost on the rear
panel voltage selector plate before applying mains
power to the SCA2. The mains voltage selection
can be adjusted by lifting the selector plate marked
with the four legends (100, 120, 220, 230) with a
small screwdriver and re-inserting the plate with
the correct voltage uppermost.
The mains cable is specifically supplied to comply
with local statutory safety approvals and
alternatives should not be substituted. If you
intend to use your SCA2 in an alternative
territory please contact ATC for advice. If an
alternative mains plug is required it must be
connected with the BROWN cable to LIVE, BLUE
cable to NEUTRAL and GREEN/YELLOW cable
to EARTH. On no account should the SCA2 mains
cable be connected without an effective mains
earth.
A power supply fuse is fitted within the SCA2 but
it is not intended to be user replaceable. If you
suspect that the power supply fuse has failed the
SCA2 should be returned to ATC or the local
representative for service. For 230/240V
operation a 3A fuse should be fitted to the mains
plug.
Page 9
8
Installation
SCA2
Diagram 1 - SCA2 rear panel and connection sockets
Diagram 2 - SPH2 Board and Link Locations
Diagram 3 - SPH2 Load Capacitor and Resistor Options
2.4 Inputs
The SCA2 can accept two balanced XLR inputs
and six unbalanced RCA phono style inputs (2 as
part of tape record/listen sets).The rear panel and
input sockets are illustrated in Diagram 1.The input
types and their identifying legends are illustrated in
following Table A.
The AUX 2 input sockets will function as a high-
sensitivity phono input if the optional SPH2 RIAA
Vinyl Board is installed.The RIAA circuitry can be
configured to accommodate a wide selection of
phono cartridge types by setting combinations of
board mounted links.Access to the board is gained
by removing the top panel of the preamplifier.
Diagram 2 illustrates the position of the links on
the board while Diagram 3 and Table B detail the
cartridge gain and input matching options available.
Links are moved by pulling them gently away from
the board with a small pair of pliers and are
replaced in the appropriate positions as shown in
the diagrams. Unused links can be “parked” on the
board by setting them at right angles on unused
pins.
The SPH2 board is split into two identical channels.
For the sake of clarity on the diagrams, the settings
for only one channel are shown. Settings for one
channel should be duplicated on the other. The
cartridge gain and matching options should be used
as described below.
Gain: Gain is set by fitting the Z link in one of two
positions (Z1 to Z2 or Z2 to Z3) and by setting a
combination of X and Y links.These links should be
fitted according to the desired input sensitivities
specified in Table B.
Table A - Input Sockets
Input socket types and legends
Rear Panel Front Panel Input Notes
Legend Legend Type
balanced input cd cd bal XLR balanced x 2
balanced input aux 1 aux 1 XLR balanced x 2
input aux 2 aux 2 RCA phono x 2 Marked “phono” on rear if
SPH2 RIAA board fitted
input tuner tuner RCA phono x 2
input tv/av a/v RCA phono x 2
input cd cd RCA phono x 2
input tape 2 tape 2 RCA phono x 2 Part of record/listen set
input tape 1 tape 1 RCA phono x 2 Part of record/listen set
Z1
Z2
Z3
X-X
Y- Y
Resistor bank.
See Diagram 3
Capacitor bank.
See Diagram 3
Link across for 400Ω
Link across for 500Ω
Link across for 300Ω
Link across for 600Ω
Link across for 200Ω
Link across for 700Ω
Link across for 100Ω
Trim -50Ω
Link across for 2200pF
Link across for 1000pF
Link across for 470pF
Link across for 220pF
Link across for 100pF
Page 10
SCA2
Preamplifier
Table B - RIAA Board Gain Stage Link Setting
Mid point gain stage set LOW (11dB) Link Z1 to Z2
First gain stage settings.
Gain Setting Gain mV Gain dB Link Position
High 1.14mV 59dB Link both Y-Y and X-X
High/mid 1.6mV 55dB Link Y-Y only
Mid 3.3mV 49dB Link X-X only
Low 33.0mV 30dB No links
Mid point gain stage set HIGH (24dB) Link Z2 to Z3
First gain stage settings.
Gain Setting Gain mV Gain dB Link Position
High 0.25mV 71dB Link both Y-Y and X-X
High/mid 0.38mV 68dB Link Y-Y only
Mid 0.78mV 62dB Link X-X only
Low 7.5mV 42dB No links
Capacitive Load: Capacitive load is set by selecting a link for the appropriate
capacitance value as illustrated in Diagram 3. Multiple links may be be used, in which
case the load value is the sum of the selected values. For example, links in the 470pF
position and 1000pF position give a total load value of 1470pF.
Resistive Load: Resistive load is set by selecting a link for the appropriate
capacitance value as illustrated in Diagram 3. If no link is selected the default
resistive load is 47 kilohms - appropriate for the majority of moving-magnet
cartridges.A link in the -50Ω position will reduce any selected load by 50 ohms. For
example, links in the 200Ω position and -50Ω position give a total load value of
150Ω.
Cartridge suppliers and manufacturers will be able to provide details of the loading
and gain settings appropriate to their products.On some occasions there will be no
specific recommendation for the capacitive load on moving-
coil cartridges. In these cases it is best to assume no
capacitance need be selected (no links used).
The rear panel ground terminal should be used to connect
the pick-up arm earth lead.
2.5 Outputs
The SCA2 rear panel, illustrated in Diagram 1, carries
sockets for balanced main left and right output, unbalanced
main main left and right output, and two unbalanced tape
record outputs.
Choice between the balanced and unbalanced main outputs
will depend on the input capabilities of the following power
amplifier (or active speakers). Use the balanced option in
preference if both options are possible.
Connections to the primary output XLR sockets
follow the convention of pin 1 to ground, pin 2 to
signal “hot” and pin 3 to signal return (signal
ground).When connecting to equipment with XLR
(balanced) inputs the connectors should be wired
pin for pin (ie. 1 to 1, 2 to 2 and 3 to 3). Diagram
4 illustrates the XLR output pin arrangement and
Diagram 5 the connection scheme for a balanced
XLR - XLR cable.
The unbalanced main left and right outputs and the
tape record outputs should be connected using
good quality RCA phono terminated leads. Use of
the front panel volume, mute, or gain functions
does not effect the tape record signal.
Cables up to 50 metres in length may be
connected to the main outputs.Tape record cables
should be limited to 10 metres.
2.6 Operation
Once connected to mains power and powered-up
from the rear panel mains switch, the front panel
Standby Reset button (or remote handset Standby
button) will switch the SCA2 between standby and
active modes. In standby mode the Standby Reset
indicator will illuminate. Operating the Standby
Reset function will switch the SCA2 into active
mute mode. The Standby Reset indicator will
extinguish and the Mute indicator will illuminate.
Diagram 4 - balanced output socket pins
Pin 1, ScreenPin 2, Signal (hot)
Pin 3, Signal (return)
Diagram 5 - balanced cable pin connections
Two Core Screened Cable
3 Pin Male XLR
Connector
3 Pin Female XLR
Connector
To Preamp Output
Hot
Return
Screen
To Power Amp or
Monitor Input
1
2
3
1
2
3
9
Page 11
SCA2
10
Operation cont’d
Diagram 6 - SCA2 front panel and controls
The Mute function automatically engages when
the SCA2 is switched from standby to active
mode. This precautionary feature provides an
opportunity for the volume and input settings to
be checked before audio is passed to the power
amplifiers.
If all is well, the SCA2 may be brought into full
operation by pressing the Mute function.The Mute
indicator will extinguish.The Mute function can be
used at any time to silence the system.
Inputs are selected by rotating the Monitor select
control.The green indicator next to each monitor
option will illuminate to indicate selection. The
control has continuous movement. When it is
moved to the last input,further rotation will select
the first input.
Volume level is adjusted by rotating the Level
control. A red indicator on the control indicates
the level selected.
Volume level can be reduced immediately by 12dB
by operating the Gain function.The Gain indicator
illuminates to indicate its use.
Optimum sound quality will be achieved when the
SCA2 has reached normal operating temperature
and for this reason it is recommended that it be
left in standby mode when not in use. It is a wise
precaution however to switch-off the SCA2 from
the rear panel power switch if it is to be left
unused for an extended period.
The Record select control selects the input source
routed to the tape outputs. The green indicator
next to each record option will illuminate to
indicate selection. The control has continuous
movement. When it is moved to the last input,
further rotation will select the first input. The
source selected is made available at the tape
output sockets and is fully buffered to prevent
signal interaction.The Level, Gain and Mute functions have no effect on the record
output signals.
Tape copying can be performed by selecting Tape 1 on the Record control to copy
from Tape 1 to Tape 2. In this case no signal will be routed to the Tape 1 output
sockets. Copying from Tape 2 to Tape 1 can be achieved in a similar manner.
Selecting Tape 1 on the Monitor control while also recording to Tape 1 (i.e. tape 1
is also selected on the record control) enables the off-tape signal from a three head
tape machine to be monitored.The Tape 2 circuit works in an identical manner.
Due to the nature of the electronics in ATC amplifiers it is quite normal for a sound
to be heard from the speaker when the power is applied or disconnected.The noise
heard will not damage the speaker and is quite normal. Although ATC uses the
highest-grade components, a different noise may be heard from each speaker due to
slight tolarance variations in the amplifier components.
2.7 Remote Handset
The optional SCA R remote handset can be used to control the SCA2. Provided that
the SCA2 is connected to mains power and its rear panel power switch is on, the
handset provides for remote operation of all the SCA2 functions. The SCA R also
includes a standard set of CD transport commands which may be used to control any
CD or DVD / SACD player that supports the standard RC5 control code set.
Use the handset On/Reset button to switch the SCA2 into active mode and the
Standby button to return the SCA2 to standby mode. Monitor and Record selection
can be made by pressing the desired monitor or record button. The SCA2 front
panel source indicators will illuminate but the rotary controls will not rotate.
Volume is controlled through the handset Level + and - buttons. The SCA2 front
panel Level control will rotate in response to handset level commands.The handset
Attn button is equivalent to the front panel Gain function. The handset Mute
function operates in exactly the same way as the front panel control.
Reliable operation of the remote handset requires direct line of sight between the
handset and the SCA2 front panel. Correct operation is indicated by illumination of
the red indicator on the left hand side of the front panel as handset commands are
received.
The red indicator on the handset will flash as functions are operated. Failure of this
indicator points to exhaustion of the handset battery. The battery should be
replaced, and the old one disposed of, by your local dealer or distributor.
Page 12
SCA2
11
There are no components within the SCA2 or
SCA R that would benefit from regular
maintenance.There is no requirement for any kind
of routine service work and there is no schedule
for preventative maintenance.
There are no user replaceable parts within the
units and in the unfortunate event of any
malfunction, repair should be referred to either
the supplying dealer or consultant, the relevant
distributor, or ATC.
2.9 Warranty and Contact
All ATC products are guaranteed against any
defect in materials or workmanship for a period of
two years from the date of purchase. Within this
period we will supply replacement parts free of
charge provided that the failure was not caused by
misuse, accident or negligence.
Purchasers who complete and return the
Warranty Card will have their warranty period
extended up to a period of six years from the
date of purchase.This guarantee does not limit
statutory rights.
ATC can be contacted at:
Loudspeaker Technology Ltd, Gypsy Lane, Aston
Down, Stroud, Gloucestershire GL6 8HR, UK.
Telephone: 01285 760561
Fax: 01285 760683
Email: info@atc.gb.net
Website: www.atc.gb.net
SCA2
Specifications
ATC reserves the right to vary products and specifications without prior notice.Acoustic Transducer Co. is a trading name and ATC
is the registered trade mark of Loudspeaker Technology Ltd.
MAIN OUTPUTS
Output Level 15V RMS into 600 Ohms balanced
7.5V RMS into 600 Ohms unbalanced
Output Impedance 10 Ohms
Effective Input Noise
<
-120dB (all inputs)
Total Harmonic Distortion
<
-114dB (0.0002%)
Crosstalk
<
-100dB at 1kHz
Frequency Response DC - 500kHz
Linearity (Left-Right) >0.2dB
Input Sensitivity 150mV for 1V out at full gain
Input Impedance 5k Ohms
Connectors XLR (balanced)
RCA Phono (unbalanced)
TAPE OUTPUTS
Signal to Noise Ratio >100dB
Total Harmonic Distortion
<
-95dB
Crosstalk -100dB
Frequency Response 10Hz - 80kHz
Output Level 0dB
Connectors RCA Phono
INPUTS
Sensitivity (for 1V output) 275mV (balanced)
150mV (unbalanced)
Input Impedance >5kΩ (balanced)
>10kΩ (unbalanced)
Primary Gain Stage 0dB (balanced)
+6dB (unbalanced)
Connectors XLR (balanced)
RCA Phono (unbalanced)
POWER REQUIREMENTS
Supply Selectable -100V to 240V, 50/60Hz
Power Consumption 10VA - 35VA
DIMENSIONS
Dimensions (HxWxD) 100 x 440 x 360mm
Overall Weight 9.5kg (21lb) unpacked
11.5kg (25.3lb) packed
Finish Grey and clear anodised aluminium.
2.8 Care and Maintenance
High technology metal finishes are used in these products.The surfaces are durable
and with a little care can be kept as good as new even under conditions of heavy
use. Normally a dry duster will be all that is required to keep the finishes clean.
Heavier soiling of the aluminium casing of the SCA R handset and SCA2 corners and
control knobs can be cleaned using a cloth slightly moistened with a non-abrasive
household cleaner - taking extreme care not to allow any liquid to enter the units.
Switch off and disconnect the SCA2 from the mains power before cleaning.
Page 13
I n t e g r a t e d A m p l i f i e r
SIA2-150
12
3 . 1 D e s c r i p t i on
The SIA2-150 is a high quality integrated amplifier
designed to partner ATC passive monitors and
other loudspeaker systems. It incorporates five
Selection of SIA2-150 inputs is achieved via a
rotary control. Output volume adjustment is
achieved through a precision potentiometer. A tape
monitor function can be selected from a front panel
push button.The tape output is a duplicate of the
signal selected by the input selector. A standby
function is also accessible from a front panel push
button. Mains power is applied from a rear panel
mounted switch.
The SIA2-150 incorporates the same gain reduction
and loudspeaker protection circuits as ATC’s active
monitors.This ensures that even when working at
very high levels the amplifier is held back from
clipping so improving the subjective performance
and protecting the loudspeakers from damage.
All SIA2-150 functions are duplicated on the
included ATC SCAR-B remote control handset.
3 . 2 I n s t a l l a t io n
The SIA2-150 is designed to be free standing
either within an equipment stand or simply on an
item of furniture. Please contact ATC for advice if
the amplifier is required to be mounted in an
enclosed area. It is recommended that at least 100
mm (4 inches) clearance is left behind the unit for
plugs and cables.
The SIA2-150 is designed to remain powered-up
in Standby mode unless it is to be unused for a
long period of time.The power dissipation of the
SIA2-150, in either standby or operational mode,
will make it warm to the touch. Temperature
stability will be reached after approximately three
hours from mains switch-on. Full audio
performance is however available immediately.
The SIA2-150 should ideally be located so as to
minimise the cable lengths from both the source
components and to the loudspeakers. Use of
loudspeaker cables in excess of 20 metres risks
causing noticeable degradation in sound quality.
3 . 3 M a i n s C o n n e c t i o n
The SIA2-150 can be used with mains voltages from 100V to 240V, 50/60Hz. Mains
voltage is factory set and should only be adjusted by ATC or your local dealer or
distributor. It is wise to ensure that the local mains voltage matches that specified
on the rear panel before applying mains power to the SIA2-150.
The mains cable is specifically supplied to comply with local statutory safety
approvals and alternatives should not be substituted. If you intend to use your SIA2-
150 in an alternative territory please contact ATC for advice. The mains connection
must always be earthed.
A power supply fuse is fitted to the rear panel of the SIA2-150. The fuse is 20mm
“Type T anti-surge”. Should the SIA2-150 fail to switch on when the power switch
is operated the fuse should be inspected. Lift out the fuse holder cover using a small
flat-blade screwdriver, remove the fuse and inspect it for damage. The fuse rating is
3.15A for 200V - 250V mains voltage and 6.3A for 100V - 120V. Fuses most often
fail only because of a serious electrical fault. If this is the case then simply replacing
the fuse will only result in another fuse failure. The SIA2-150 should be returned to
ATC for service if a second fuse fails.
3 . 4 I n p u t s
The SIA2-150 accepts unbalanced RCA Phono style inputs sockets. The signal is
present on the centre conductor of an unbalanced input and the signal return is
made via the screened outer.If there is any hum present on the inputs this must be
traced to its source and not suppressed by the removal of screens or earths.
Removal of the screen on an unbalanced input is likely to result in uncontrollably
loud hum.The input sockets are illustrated in Diagram 1.
All inputs are line-level sensitivity via RCA phono connectors on the rear panel.
electrically identical and a line-level signal from any source equipment type may be
connected to any input.
line level stereo inputs plus headphone jack,
stereo record, pre and sub outputs on RCA
phono sockets and one pair of loudspeaker
outputs on WBT connectors..
Inputs are labelled for Tape, Aux, Av, Tuner and CD. However, th. ey are
Page 14
SIA2-150
13
3.5 Outputs
The SIA2-150 rear panel, illustrated in Diagram 1, carries connectors for left and
right loudspeaker, and tape left and right outputs on RCA Phono sockets.
Loudspeaker connections are made using the two pairs of WBT connectors on the
rear panel.The left and right channels are clearly marked and correspond to the left
and right inputs. The loudspeaker terminals are labelled positive and negative. The
wire used for the connections to the monitors will have some identification for the
positive conductor. Usually this is red,but may be a moulded stripe on the insulation.
The positive conductor connects to the positive terminal on the SIA2-150 and also
to the positive or red connector on the rear of the monitor.The terminals on the
rear of the SIA2-150 will accept either bare wire up to 5.7mm diameter or 4mm
male plugs.When bare wire connections are made the insulation should be carefully
removed from each conductor with a sharp knife to expose 12mm of conductors.
The conductors should be tightly twisted together and inserted into the connector
ensuring that no stray strands of wire cause a short circuit.
It is important that both loudspeakers are connected with the same polarity.That is;
both positive loudspeaker terminals are connected back to positive amplifier
terminals and both negative loudspeaker terminals connected back to negative
amplifier terminals.
The SIA2-150 is suitable for loudspeaker systems with a nominal impedance of 4
Ohms or greater.
The tape record outputs should be connected using good quality RCA phono
terminated leads. Use of the front panel volume, mute, or gain functions does not
affect the tape record signal. Tape record cables should be limited to 10 metres in
length.
3.6 Operation
Once connected to mains power and powered-up from the rear panel mains switch,
the front panel Standby button (or remote handset Standby button) will switch the
SIA2-150 between standby and active modes. In Standby mode the Standby indicator
illuminates. Operating the Standby function from either the front panel or remote
handset will switch the SIA2-150 into active mode. The Standby indicator will
extinguish and be replaced by the Input Select indicator showing the current selection.
Operating the Standby function again will return the SIA2-150 to Standby mode.
Diagram 1 - SIA2-150 rear panel and connectors
Inputs are selected by rotating the Input Select
control in either direction. The control has
continuous movement. When it is moved to the
last input, further rotation will select the first
input.
A separate tape loop is included with a Monitor
option selected by a single push button on the
front panel. The tape output carries the same
signal as selected by the Input Select control.
Operation of the Standby or Tape Monitor
functions will not affect the tape output providing
mains power is maintained.
Output level is controlled by the rotary Volume
control on the front of the unit, the position of
which is indicated by a small gold pin.Rotating the
control clockwise will increase the output level. It
is good practice to lower the volume setting
before switching on the preamplifier or any
associated equipment, or while changing the input
selection.
Due to the nature of the electronics in ATC
amplifiers it is quite normal for a sound to be
heard from the speaker when the power is applied
or disconnected.The noise heard will not damage
the speaker and is quite normal. Although ATC
uses the highest-grade components, a different
noise may be heard from each speaker due to
slight tolarance variations in the amplifier
components.
3.7 Remote Handset
Included with the SIA2-150 is the ATC SCAR-B
remote control handset.This provides for remote
operation of all the SIA2-150 functions and
includes a standard set of CD transport
Installation
Page 15
S p e c i f i c a t i o n s
SIA2-150
14
O p e r a t i o n c o n t ’ d
3 . 7 R e m o t e H a n d s e t c o n t ’d
commands which may be used to control any CD
or DVD / SACD player that supports the RC5
control code set. Power is supplied by 4 x AAA
batteries (included).
3 . 8 C a r e an d M a i n t e n a n c e
High technology material finishes are used in this
product.The surfaces are durable and with a little
care can be kept as good as new even under
conditions of heavy use. Normally a dry duster will
be all that is required to keep the finishes clean.
Heavy soiling can be cleaned using a cloth slightly
moistened with a non-abrasive household cleaner.
There are no components within the SIA2-150
that can be considered expendable, or that would
benefit from regular maintenance. There is no
requirement for any kind of routine service work
and there is no schedule for preventative
maintenance.
There are no user replaceable parts within the
unit and in the unfortunate event of any
malfunction, repair should be referred to either
the supplying dealer or consultant, the relevant
distributor, or ATC.
SIA2-150
ATC reserves the right to vary products and specifications without prior notice.Acoustic Transducer Co. is a trading name and ATC
is the registered trade mark of Loudspeaker Technology Ltd.
Output Power 150 Watts per channel into 8 Ohms
Input Sensitivity 350mV
Input Impedance 22k Ohms
Signal/Noise 100dB >
Amplitude Response 5Hz - 200kHz ±0.1dB
Crosstalk
<
-90dB
Power Requirements: 100, 115, 230V factory set, 50/60Hz
Power Consumption 10 VA (standby minimum)
230VA (powered)
500VA (maximum)
Dimensions (HxWxD) 135 x 435 x 350mm
OverallWeight 20kg (44lb)
Finish Titanium anodised aluminium
3 . 9 Wa r r a n t y a n d C o n t a c t
All ATC products are guaranteed against any defect in materials or workmanship for
a period of two years from the date of purchase. Within this period we will supply
replacement parts free of charge provided that the failure was not caused by misuse,
accident or negligence.
Purchasers who complete and return the Warranty Card will have their
warranty period extended up to a period of six years from the date of
purchase.This guarantee does not limit statutory rights.
ATC can be contacted at:
Loudspeaker Technology Ltd, Gypsy Lane,Aston
Down, Stroud, Gloucestershire GL6 8HR, UK.
Telephone: 01285 760561
Fax: 01285 760683
Email: info@atc.gb.net
Website: www.atc.gb.net
Page 16
Power Amplifiers
SPA2-150/200P
15
4.1 Description
The SPA2-150 and SPA2-200P are high quality power amplifiers designed to partner
ATC passive monitors and other loudspeaker systems. They are both capable of
output power considerably in excess of specification. Both also incorporate the same
gain reduction and loudspeaker protection circuits as ATC’s active monitors. This
ensures that even when working at very high levels the amplifiers are held back from
clipping so improving the subjective performance and protecting the loudspeakers
from damage.
The SPA2-200P features a stereo pair of balanced inputs on XLR sockets while the
SPA2-150 incorporates switch selectable balanced and unbalanced signal inputs on
XLR and RCA phono sockets respectively. Loudspeaker output connections on both
power amplifiers are made through two pairs of WBT connectors.
The SPA2-200P includes a multi-pin connector on the rear panel that provides wired
remote control interface facilities while the SPA2-150 can be switched into and out of
Standby mode by either ATC remote handset.
Both power amplifiers incorporate comprehensive performance monitoring and
feedback through a front panel display.
4.2 Installation
The SPA2-200P and SPA2-150 are designed to be free standing. The power
dissipation of the amplifiers is considerable and makes them warm to touch.
Temperature stability will be reached after approximately three hours from mains
switch-on but full audio performance is available immediately and is not influenced
by temperatures within the amplifiers’ normal operating range. Care must be taken
not to obscure the ventilation holes in the top and bottom covers. Please contact
ATC for advice if the amplifier is required to be mounted in an enclosed area.
The SPA2-150 is an aesthetic match for the SCA2 preamplifier and it is quite in
order to sit the SCA2 on top of the SPA2-150.A general recommendation regarding
the layout of the system is that the distance between the power amplifier and
loudspeakers should be minimised. Reducing the length of speaker cables improves
the control of amplifier over the loudspeaker system through the reduced
resistance of the loudspeaker leads. It may therefore be appropriate to locate the
power amplifiers close to the loudspeakers.
There is no general benefit from reducing the length of the interconnect from the
an ATC preamplifier to the power amplifier, especially when balanced connections
are used. However, non ATC preamplifiers may not be capable of driving cables of
more than a few metres.
4.3 Mains Connection
The SPA2-150 and SPA2-200P can be used with mains voltages from 100V to 240V,
50/60Hz. Mains voltage is factory set and should only be adjusted by ATC or your
local dealer or distributor. It is wise to ensure that the local mains voltage matches
that specified on the rear panel before applying mains power.
The mains cable is specifically supplied to comply
with local statutory safety approvals and
alternatives should not be substituted. If you
intend to use your power amplifier in an
alternative territory please contact ATC for
advice. The mains connection must always be
earthed.
A power supply fuse is fitted to the rear panels of
the power amplifiers. The fuse is 20mm “Type T
anti-surge”. Should a unit fail to switch on when
the power switch is operated the fuse should be
inspected. Lift out the fuse holder cover using a
small flat-blade screwdriver, remove the fuse and
inspect it for damage. The fuse rating is 3.15A for
200V - 250V mains voltage and 6.3A for 100V -
120V. Fuses most often fail only because of a
serious electrical fault. If this is the case then
simply replacing the fuse will only result in another
fuse failure. The power amplifier should be
returned to ATC for service if a second fuse fails.
4.4 Inputs
The SPA2-150 is fitted with both unbalanced RCA
Phono and balanced XLR inputs. A switch on the
rear panel selects between the two. The SPA2-
200P incorporates only balanced XLR inputs.
Note: Do not attempt to connect both balanced
and unbalanced inputs at the same time. The
selector switch is not a toggle between the two
inputs. The XLR and RCA input connectors are
wired in parallel and the switch merely arranges
for either balanced or unbalanced input.
The signal is present on the centre conductor of
an unbalanced RCA Phono style input and the
signal return is made via the screened outer. If
there is any hum present on the inputs this must
be traced to its source and not suppressed by the
removal of screens or earths. Removal of the
screen on an unbalanced input is likely to result in
uncontrollably loud hum.
All signal cables and plugs should be of a good
quality. Poor cable and plug quality will
compromise the performance of your system.The
signal input pin configuration for XLR sockets is
illustrated in Diagram 1 while Diagram 2 illustrates
a balanced cable.
Page 17
16
Power Amplifiers
SPA2-150/200P
4.5 Signal Cable Options
Balanced cables are always the preferred option,
for the SPA2-150P however unbalanced
connection is possible. Diagrams 2 and 3 illustrate
the signal cable connections required for each
option. Balanced (XLR to XLR) connection offers
lower noise and better immunity to “hum” pick-
up. Unbalanced (XLR to Phono or Two Pole Jack)
connection carries risk of hum caused by multiple
signal earths.
Hum problems resulting from unbalanced
connection may be reduced by making ONE of the
following modifications to the signal cable
connections: If the driving preamplifier (or desk) is
“double insulated” (i.e. has no mains earth),
disconnect the signal cable screen at the RCA
Phono plug end. Alternatively, disconnect the signal
cable screen at the XLR end.This second option will
make the source the reference signal earth.
4.6 Outputs
Loudspeaker connections are made to the SPA2-
150 and SPA2-200P through WBT connectors on
the rear panels. The left and right channels are
clearly marked. The loudspeaker terminals are
labelled positive and negative. The wire used for
the connections to the monitors will have some
identification for the positive conductor. Usually
this is red, but may be a moulded stripe on the
insulation. The terminals will accept either bare
wire up to 5.7mm diameter or 4mm male plugs.
When bare wire connections are made the
insulation should be carefully removed to expose
12mm of conductor. The conductors should be
tightly twisted together and inserted into the
connector ensuring that no stray strands of wire
cause a short circuit.
It is important that both loudspeakers are
connected with the same polarity. That is; both
positive loudspeaker terminals are connected back
to positive amplifier terminals and both negative
loudspeaker terminals connected back to negative
amplifier terminals.
The SPA2-150 and SPA2-200P are suitable for
loudspeaker systems with a nominal impedance of
4 Ohms or greater.
Diagram 1 - input connection pins
Diagram 2 - balanced cable
Diagram 3 - unbalanced cable
Pin 1, ScreenPin 2, Signal (hot)
Two Core Screened Cable
Pin 3, Signal (return)
3 Pin Male XLR
Connector
3 Pin Female XLR
Connector
To Power Amplifier
Input
Hot
Return
Screen
To Source Output
1
2
3
1
2
3
Two Core Screened Cable
3 Pin Male XLR
Connector
Phono (RCA)
Connector
To Power Amplifier
Input
Hot
Return
Screen
To Source Output
1
2
3
4.7 Operation
Once connected to mains power and powered-up from the rear panel mains switch,
the front panel Standby button (or ATC remote handset Standby button) will switch
the SPA2-150 between standby and active modes. The SPA2-200P can only be
operated remotely by a custom wired remote system
With the power switch on, the front panel Standby indicator will illuminate. The unit
will then respond to control either from the front panel or, in the case of the SPA2-150
an ATC remote handset.The Standby button on the front panel will switch the amplifier
between active and standby modes.The rear panel power switch should be used to
isolate the SPA2-150 and SPA2-200P from the mains supply if the units are to be unused
for any significant period.
When switched into active mode the unit will go into an initialisation sequence under
the control of the internal microprocessor.The standby indicator will extinguish and
be replaced by the LED display displaying
0 followed by a flashing decimal point. At
this time it is quite possible that the loudspeakers will emit a mild thump as the
Installation cont’d
Page 18
SPA2-150/200P
17
amplifier powers up and the initialisation routine is
carried out. When, after a few seconds, the
initialisation is complete, the figure
0 is replaced by
a constantly lit decimal point.The unit is now in the
normal active mode. The initialisation sequence is
illustrated in Diagram 4.
An indicator adjacent to the left of the Standby
button illuminates when the amplifier receives
remote control signals. It will also illuminate if the
signals received are not intended for the amplifier -
CD or preamplifier controls for example.
At all times during the operation of the SPA2-150
and SPA2-200P their internal microcomputer will
monitor the important aspects of amplifier
operation.Their front panel LED displays will warn
of overdrive and fault conditions on either or both
channels. The units will shut down if excessive
temperature or DC offset faults arise but, as the
amplifiers are designed to accommodate
overdriving abuse indefinitely, they will keep
running. Sound quality will however be impaired by
the operation of the protection circuitry. There is
also the possibility of damage to the loudspeakers
when driven at such high levels. It is therefore
prudent to reduce the system volume level to
below the overdrive indication threshold. The
display and its interpretation is illustrated in
Diagram 4.
Excessive temperature and DC offset are both
potentially very damaging and the amplifier will
shutdown whilst displaying the fault condition that
caused the problem. Excessive temperature is only
likely if the output load is too great or if the
ventilation is inadequate.The amplifier will not reset
until the operating temperature has had time to
return to normal. DC offsets generally indicate a
faulty source or preamplifier. The power amplifier
will not reset until the fault has been cleared.
Due to the nature of the electronics in ATC
amplifiers it is quite normal for a sound to be
heard from the speaker when the power is applied
or disconnected.The noise heard will not damage
the speaker and is quite normal. Although ATC
uses the highest-grade components, a different
noise may be heard from each speaker due to
slight tolarance variations in the amplifier
components.
Diagram 4 - Display legends
Initialisation:The decimal point flashes to show initialisation is in
progress.
Normal Operation:The decimal point illuminates to show the amplifier
is powered-up and is healthy.
Over Temperature: Indicates that the temperature is over 90ºC in the
left amplifier channel.This condition will shut down the amplifier.
Pressing the Standby button will restore the amplifier to normal only if
the temperature has dropped significantly.
Over Temperature: Indicates that the temperature is over 90ºC in the
right amplifier channel.This condition will shut down the amplifier.
Pressing the Standby button will restore the amplifier to normal only if
the temperature has dropped significantly.
Over Temperature: Indicates that the temperature is over 90ºC in both
amplifier channels.This condition will shut down the amplifier. Pressing
the Standby button will restore the amplifier to normal only if the
temperature has dropped significantly.
DC Offset: Indicates a DC voltage of greater than 1V present on the
output of the left amplifier.This condition will shut down the amplifier.
Pressing the Standby button will restore the amplifier to normal only if
the fault has been cleared.
DC Offset: Indicates a DC voltage of greater than 1V present on the
output of the right amplifier.This condition will shut down the
amplifier. Pressing the Standby button will restore the amplifier to
normal only if the fault has been cleared.
DC Offset: Indicates a DC voltage of greater than 1V present on the
output of both amplifiers.This condition will shut down the amplifier.
Pressing the Standby button will restore the amplifier to normal only if
the fault has been cleared.
Overdrive: Indicates that maximum drive has been reached on the left
amplifier and that the gain reduction circuits are operating to prevent
clipping.
Overdrive: Indicates that maximum drive has been reached on the
right amplifier and that the gain reduction circuits are operating to
prevent clipping.
Overdrive: Indicates that maximum drive has been reached on both
amplifiers and that the gain reduction circuits are operating to prevent
clipping.
Operation cont’d
4.8 Remote Operation
ATC remote control handsets may be used with the SPA2-150 to provide remote
operation of the standby function.
The SPA2-200P incorporates a rear panel multipin connector that enables custom
remote control systems to be developed. Please contact ATC directly for technical
information and advice on the development of such systems.
Page 19
18
4.10 Warranty and Contact
All ATC products are guaranteed against any defect in materials or workmanship for
a period of two years from the date of purchase.Within this period we will supply
replacement parts free of charge provided that the failure was not caused by misuse,
accident or negligence.
Purchasers who complete and return the Warranty Card will have their
warranty period extended up to a period of six years from the date of
purchase.This guarantee does not limit statutory rights.
ATC can be contacted at:
Loudspeaker Technology Ltd, Gypsy Lane, Aston
Down, Stroud, Gloucestershire GL6 8HR, UK.
Telephone: 01285 760561
Fax: 01285 760683
Email: info@atc.gb.net
Website: www.atc.gb.net
SPA2-150 SPA2-200P
Specifications
ATC reserves the right to vary products and specifications without prior notice.Acoustic Transducer Co. is a trading name and ATC
is the registered trade mark of Loudspeaker Technology Ltd.
Output Power 150 Watts/Channel into 8 Ohms 200 Watts/Channel into 8 Ohms
Balanced Input Sensitivity 1V 1V
Balanced Input Impedance 10 kilohms 10 kilohms
Balanced Input C.M.R.R -90dB @ 1kHz -90dB @ 1kHz
Unbalanced Input Sensitivity 2V 2V
Unbalanced Input Impedance 10 kilohms 10 kilohms
Signal/Noise >110dB >110dB
Amplitude Response 5Hz - 200kHz ±0.1dB 5Hz - 200kHz ±0.1dB
Crosstalk
<
-105dB
<
-105dB
Distortion (at rated power)
<
-95dB
<
-95dB
Power Requirements: 100, 115, 230V factory set, 50/60Hz 100, 115, 230V factory set, 50/60Hz
Power Consumption 10 VA (Standby minimum) 10 VA (Standby minimum)
180 VA (Nominal) 180 VA (Nominal)
600 VA (Rated Output) 600 VA (Rated Output)
Dimensions (HxWxD) 146 x 440 x 426mm 130 x 428 x 325
Overall Weight 26kg (57.3lb) 22kg (48.5lb)
SPA2-150/200P
4.9 Care and Maintenance
High technology metal finishes are used in these
products.The surfaces are durable and with a little
care can be kept as good as new even under
conditions of heavy use. Normally a dry duster will
be all that is required to keep the finishes clean.
Heavier soiling of the aluminium can be cleaned
using a cloth slightly moistened with a non-
abrasive household cleaner - taking extreme care
not to allow any liquid to enter the units. Switch
off and disconnect the units from the mains power
before cleaning.
There are no components within the units that
would benefit from regular maintenance.There is
no requirement for any kind of routine service
work and there is no schedule for preventative
maintenance.
There are no user replaceable parts within the
units and in the unfortunate event of any
malfunction, repair should be referred to either
the supplying dealer or consultant, the relevant
distributor, or ATC.
Page 20
ACOUSTICENGINEERS
®
Loudspeaker Technology Ltd, Gypsy Lane, Aston Down, Stroud, Gloucestershire GL6 8HR United Kingdom
Telephone 01285 760561 Fax 01285 760683
Email: info@atc.gb.net Website: www.atc.gb.net
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