02 welcome
08 key features
10 getting started
12 selecting an input
14 volume control
15 gain control
17 headphones
contents
18 grounding
19 outputs
21 connecting power amplifiers
27 running in and warming up
28 care and maintenance
30 technical data
34 international standards
GAIN
0dB
220-240V
~
50-60Hz
Fuse: T1A L250V
3
fuse
carrier
6
9
12
15dB
made in United Kingdom
ac supply
socket
RECORDINPUTVOLUME
tape 2
tape 1
tape 3
tuner
cd
aux
remote control
mute
LED
output
sockets
OUTPUT
in
left
right
transformer
balanced
3
right
(option)
XLR output
(optional)
2
left
right
left
right
ground
ground
terminal
window
31aux tuner cd
left
transformer
balanced
(option)
XLR output
(optional)
SOURCE
input
sockets
left
right
tuner
aux
cd
out 321inoutinout
left
right
serial
PA2 1234567
number
tape 1
tape 2
tape 3
tape in/out
sockets
TAPE
Specification shown may vary for different countries
welcome to a new partnership
..in hi-performance, hi-fidelity
Derek Scotland (on the left) – Technical Director
Peter Stevens – Chief Industrial Designer
Dr. Zucker – Chief Executive
All TAG companies perpetually strive
for, and ac hieve,excellence and highperformance in every area of their
business.
These qualities are demonstrated in the
fastidious standards that make TAG Heuer
watches some of the world’s most
admired;in the teamwork that makes TAG
McLaren’s motor racing team one of the
most successful in Formula One;and in the
advanced electronics technology that
makes TAG Electronic Systems the first
choice for many Formula One constructors
and high-performance car makers.
celebrating a TAG McLaren victory
Now,this blend of talent and
expertise has been combined
with the award-winning
experience of Audiolab to create
a company with a technical
advantage and access to
resources second-to-none in the
high end audio industry TAG McLaren Audio.
TAG McLaren Audio has been created with
one aim in mind:to produce the best highfidelity audio and audio-visual systems
available. Now the first fr uits of that
alliance are ready – a unique new range of
audio products.
Throughout the F3 Series development
process,quality, performance and
reliability have been paramount,resulting
in unparalleled performance,operational
excellence and sheer listening pleasure.
03
welcome
welcome
Thank you for purchasing the TAG McLaren Audio preamplifier PA20R.
We are convinced it will give you many hours of
listening pleasure.
The PA20R is a high-performance preamplifier which acts
as the command centre for your audio system.It has
microprocessor-controlled relays with gold-plated contacts
for its switching functions and,for added convenience, you
can select inputs,adjust the volume or mute the output by
remote control.‘Straight Line Technology’gives the PA20R
exceptional sound quality with an unusually
wide and flat frequency response.
Furthermore, by painstaking attention to
detail,TAG McLaren Audio engineers have
ensured that the versatile control facilities
do not affect the excellent sound quality.
In particular,the ‘Time Constant Switching’
system ensures that the muting period is
short even though the frequency response
reaches as low as 0.1 Hz.
versatile input
and recording selection
The PA20R has six selectable inputs and
three outputs for recording.A separate signal
path is provided for recording,with its own
independent input selector, so you can
record one piece of music while listening
to another.The microprocessor-controlled
relay switching system in the PA20R
includes a lock-out function to prevent
feedback loops when using a tape recorder.
low intermodulation distortion
The theoretically-ideal preamplifier
reproduces sound perfectly over an infinite
range of frequencies – starting from well
below the audible range and extending far
above the capabilities of human hearing.
Although sound outside the human hearing
range of approximately 20 to 20,000 Hz
cannot be heard,it can significantly distort
the quality of music reproduction through
an effect that audio engineers call
‘intermodulation distortion’.This type of
distortion moves imperfections that
originate outside the hearing range back into
the audible frequencies.To minimise this
effect,TAG McLaren Audio preamplifiers
have a frequency response which extends
0504
welcome
welcome
both above and below the range of normal
human hearing.
straight line technology
To prevent intermodulation distortion,
a preamplifier must respond to very low
frequencies but block any Direct Current
(DC).This is traditionally achieved using
capacitors,which also block some of the lowfrequency signal.In the PA20R, a feedback
circuit eliminates DC offset voltage and
allows the signal path to be direct coupled
without any capacitors.This arrangement,
which we at TAG McLaren Audio call
‘Straight Line Technology’,is easy to describe
but not easy to realise.The design has taken
our expert engineers years to perfect.
time constant switching
The PA20R has a sophisticated muting
system which protects your hi-fi and
prevents annoying, loud switching noises
from reaching the output.A preamplifier
that responds to low frequencies will ‘ring’
for a long time in response to the sudden
voltage changes that happen,for example,
when you select a different input.A muting
system that simply waited for the switching
transients to die down naturally would take
far too long to settle.To overcome this
problem,the PA20R incorporates a
technique developed by TAG McLaren Audio
called ‘Time Constant Switching’.
This changes the characteristics of the
preamplifier during input switching to
reduce the settling time,so that the mute
period can be as short as possible.
control of volume and gain
Volume control on the PA20R is via a
motorised potentiometer.This gives you the
convenience of remote control without the
disadvantage of stepped volume changing,as
you might find in a digital electronic system.
The PA20R also has gain control to allow
you to select the right amount of
preamplification for your system to keep the
volume control near the middle of its range.
The gain switching facility is also used to
provide the correct volume range for a
wide variety of headphones.
high-quality circuitry
The circuits in the PA20R are ‘no-
compromise’designs using high-quality,
high-stability components to send a smooth,
clean signal to your power amplifier for
excellent sound quality.As a further
refinement,the power supplies for the
right and left stereo channels have separate
regulators to prevent any interaction
between channels.
versatile analogue output
Two low-impedance outputs are provided
for connection to power amplifiers.As an
option,the PA20R can be fitted with an
additional transformer-coupled, balanced
XLR output for improved resistance to
electromagnetic interference and mains
frequency hum.
The PA20R,at the heart of your system,
keeps everything at the highest level of
hi-performance,hi-fidelity.
0706
key featureskey features
08
‘Straight Line Technology’ with direct coupled signal and
•
feedback paths
High-quality audio components
•
Independent input selection for listening and tape recording
•
Six line level inputs for: cd, tuner, auxiliary, and three tape
•
recorders
Digitally-controlled muting system, with ‘Time Constant Switching’,
•
operates automatically and by remote control
Motorised volume control and input selector can be operated
•
manually or by remote control
Remote control also operates selected TAG McLaren Audio F3
•
Series CD players
Gain selectable in six steps
•
Three stereo outputs for recording
•
Two low-impedance stereo outputs to allow long cable runs
•
An additional transformer-coupled and balanced output, via the
•
fitted XLR connectors, can be supplied as an option
Headphone output for a wide range of impedances with
•
automatic muting when headphones are plugged in
Sorbothane
•
TAG McLaren Audio
1. For the ver y best per formance we recommend that our units are placed on
®
sonic isolation feet specially, designed by
(1)
individual shelves and are not stacked one on top of another
09
getting startedgetting started
10
before
you start
sound source
connection
amplifier
connection
power
connection
W e know you are keen to get your PA20R working. This section
will have you listening to your favourite music as quickly as possible.
If you fold out the front cover of this manual, you will locate
diagrams which will help you find your way around your P A20R
(1)
.
Make sure that all the components of your audio system are
disconnected from the AC supply whenever you change any
connections.
You will need a source of audio signals (such as our CD player
CD20R or our tuner T20) to feed into your PA20R. Use a goodquality, screened phono-phono audio cable to connect the phono
output sockets of your sound source to the appropriate pair of
left and right sockets marked SOURCE aux, tuner, cd or TAPE in
1, in 2 or in 3 on the back of your PA20R
(2)
.
Use a good-quality, screened phono-phono audio cable to connect
the phono sockets marked OUTPUT 1 left and right on the back of
your PA20R to the corresponding inputs of your power amplifier.
Check that the power button is out so that power is off when you
(3)
plug in
. Using the cable supplied, connect the socket on the back
of your PA20R to an AC supply outlet. For the best sound quality,
we recommend that you do not use multi-plug adaptors.
setting controls
switch on
Turn the VOLUME right down (all the way anticlockwise).
Set the INPUT selector to the input to which you connected your
sound source.
Set the GAIN to 9 dB.
Press the power button in. The blue power LED will come on.
Wait for a few seconds until the mute LED on the front panel
(4)
goes out
.
Start playing your sound source.
Turn up the VOLUME, sit back and enjoy the music.
1. Throughout this instruction manual (except in titles), bold print indicates the
lettering that you will find on the panels of your PA20R
2. The inputs for cd, tuner, aux, TAPE 1, TAPE 2 and TAPE 3 are all the same
electrically. They are named for your convenience
3. The power button is a latching switch. One press will hold it in, the next will
release it
4. The output is muted when the power is switched on to allow all the voltages to
stabilize. This protects your amplifier and loudspeakers and prevents unpleasant
switching noises from upsetting your listening experience
VOLUME
INPUT
tuner
aux
cd
0dB
GAIN
tape 1
tape 2
tape 3
3
6
9
12
15dB
11
selecting an inputselecting an input
TAPE
out321inout inout in
left
(4)
.
right
tape 1
tape 2
tape 3
RECORD
tuner
cd
aux
inputs for
listening
Your PA20R has six line level inputs which can be selected by
(1)
name
. The input for listening can be selected independently
from the input for recording, so you can listen to one source
and record another at the same time.
The signal from your chosen input source will be amplified and
sent to OUTPUT 1, 2 , 3
(2)
and the headphone socket. T o select your
source from the front panel, turn the INPUT selector until the mark
on its side points to the name of the input that you want to listen to.
inputs for
recording
The signal from the input that you select for recording will be sent
to the record output sockets marked TAPE out 1, out 2 and out 3
To select your source for recording, turn the RECORD selector until
the mark on its side points to the name of the input that you want
(5)
INPUT
tuner
aux
cd
tape 1
tape 2
tape 3
to record
The record output is not affected by the muting or volume controls.
.
left
right
12
using the
remote control
You can also select an input for listening by pressing the button
on the remote control marked with the name of the input
(3)
.
For optimum performance from the remote control you must point
it towards the remote control pickup window on the front panel.
The remote control can also be used with selected TAG McLaren
Audio F3 Series CD players. For details, see the separate remote
control instructions.
1. The inputs for cd, tuner, aux, TAPE 1, TAPE 2 and TAPE 3 are all the same
electrically. They are named for your convenience
2. OUTPUT 3 is only functional if your PA20R has been fitted with the optional
transformer-coupled and balanced output. See page 19 for details
3. When you use the remote control, the INPUT selector on the front panel will turn
automatically to point to the selected input. Make sure that nothing interferes
with the free movement of the selector when you use the remote control
4. The TAPE out 1, out 2 and out 3 output sockets are connected together internally
5. With many preamplifiers, a feedback loop can be created if the output and input
of a tape recorder are both connected to the preamplifier and the same tape
recorder is selected as the record input. The PA20R has microprocessorcontrolled relays which prevent this from happening
13
volume controlgain control
14
volume
mute
The VOLUME and MUTE controls alter the signal level of OUTPUT
(1)
1
, 2, 3
and the headphone socket. They do not affect the output
of the record sockets (
Turn the
VOLUME knob clockwise to increase volume and
TAPE out 1, 2 and 3).
anticlockwise to decrease volume.
Alternatively you can use the
control to increase volume and
Press the
mute button on the remote control to switch off OUTPUT
1
, 2, 3 and the headphone output. Press the mute button again or
volume + button on the remote
volume – to decrease it
(2)
.
adjust the volume to restore the output.
The PA20R also mutes for about three seconds to allow all the
voltages to stabilize whenever you change the
GAIN or an INPUT
An LED on the front panel indicates when the PA20R is muted.
1. OUTPUT 3 is only functional if your PA20R has been fitted with the optional
transformer-coupled and balanced output. See page 19 for details
2. When you use the remote control, the VOLUME knob on the front panel will turn
automatically. Make sure that nothing interferes with the free movement of the
knob when you use the remote control
3. Muting protects your PA20R, your amplifier and your loudspeakers and prevents
unpleasant switching noises upsetting your listening experience
Different power amplifier and loudspeaker combinations can give
different sound levels from an identical preamplifier output signal.
VOLUME
For your added convenience, the PA20R has a
compensate for this. The
GAIN control allows you to select the
right amount of preamplification to keep the volume knob near
GAIN control to
its middle position when listening at a comfortable sound level.
The
GAIN control also provides a suitable volume range for a wide
variety of headphones.
The
GAIN control affects the volume of the sound from OUTPUT
(1)
1
, 2, 3
and the headphone socket. It does not affect the output
from the record sockets (
(3)
.
1. OUTPUT 3 is only functional if your PA20R has been fitted with the optional
transformer-coupled and balanced output. See page 19 for details
TAPE out 1, 2 and 3).
15
gain controlheadphones
best gain setting
16
choosing the
Turn the GAIN selector to select a gain setting. Gain is the
amount of preamplification that the PA20R applies to the input
signal. It is shown in dB
(1)
.
Start with the GAIN selector in the middle of its range at 9 dB.
Play some music with roughly average dynamics and adjust the
volume to suit your normal listening. If the VOLUME knob is near
the low end of its scale, decrease the GAIN. If it is near the top
end, increase the GAIN. Choose a GAIN setting which allows the
VOLUME knob to sit nearest its middle position.
To avoid excessive sound levels from, and prevent damage to,
your loudspeakers, you should reduce the volume before you turn
up the gain.
Y ou can find the GAIN setting for your headphones in the same
way. You may find that the best setting for headphones is different
to that for your power amplifier and loudspeaker combination.
1. dB (shor t for decibel) is a logarithmic scale of the ratio between input and
output. A step of 3 dB is equivalent to a factor of two in output power, and the
human ear perceives 10 dB as an approximate doubling of the sound level
headphone
connection
GAIN
3
0dB
6
9
12
15dB
loudspeaker
muting
Turn the VOLUME down before you connect your headphones.
1
Insert the headphone plug into the
on the front panel of your PA20R
When you plug in your headphones, OUTPUT 1, 2 and 3
/
4” (6.3 mm) stereo jack socket
(1)
.
(2)
are
automatically muted.
1
1. If you want to use headphones which have the smaller
you should obtain an adaptor from your retailer. Remove the adaptor from the
socket when you are not using the headphones or the output will remain muted
2. OUTPUT 3 is only functional if your PA20R has been fitted with the optional
transformer-coupled and balanced output. See page 19 for details
/
8” (3.2 mm) jack plug,
17
groundingoutputs
left
right
left
right
1
OUTPUT
2
The AC mains supply normally operates at either 50 or 60 Hz
(depending on which country you are in). Under some
circumstances, this can cause an audible hum in your
loudspeakers.
The audio outputs are intended to connect the PA20R to one or
more power amplifiers (such as our 60P, 100P or 125M).
The low-impedance (100 Ω) output is buffered and will drive long
cables or several inputs in parallel if required.
Should you have any problems with hum in your system,
OUTPUT 1 and 2 each consists of two phono sockets on the back
panel of your PA20R, one for the left channel and one for the right
Always use high-quality, screened cables for your connections.
(1)
.
avoiding hum
please contact your retailer.
To minimise the possibility of mains hum in your system:
audio output
sockets
do not link the ground terminals of separate audio units
together.
use screened cable for your signal connections and keep
the left and right channel cables close together.
grounding
your system
All the units in the TAG McLaren Audio F3 Series are double
insulated and do not require safety ground connections.
Although a ground terminal is provided on the PA20R, for your
ground
convenience your system does not need to be connected to
ground (audio engineers call this ‘floating’). However, if you want
to ground your system, please contact your retailer who will be
able to assist you.
18
1. OUTPUT 1 and 2 are connected together in parallel
19
outputsconnecting power amplifiers
out
outin
hf
lf
left speakerright speaker
hf
lf
left
right
left
right
1
OUTPUT
2
OUTPUT
transformer-
coupled,
balanced
audio output
(option)
As an option, the PA20R can be fitted with transformers to
provide a balanced output via XLR connectors. This gives greatly
enhanced immunity to electromagnetic interference, resulting in
less noise, especially if long cables are used. This type of
connection is often used in professional applications.
Please contact your retailer if you require this option.
right
transformer
balanced
(option)
2
3
left
right
31
left
left
right
transformer
balanced
ground
(option)
Your PA20R needs to be connected to a high-quality, separate
stereo power amplifier (such as our 60P or 100P) or to a pair of
monoblocs
(1)
(such as our 125M).
Always switch off your system before changing any connections.
If you do not have the transformer-coupled, balanced output
option, the XLR sockets labelled OUTPUT 3 left and right are
not connected and cannot be used
(1)
.
using a stereo
power amplifier
Using a good-quality, screened phono-phono audio cable,
connect the phono sockets marked OUTPUT 1
(2)
left and right on
the back of your PA20R to the corresponding inputs of your
power amplifier.
When the transformer-coupled, balanced output option is
installed, you can use the XLR sockets labelled OUTPUT 3 on the
back panel of your PA20R. The output uses two XLR sockets, one
for left and one for right.
The XLR connectors are latched so you will hear a click when the
plug is fully inserted. You have to press the button on the plug to
This diagram shows a
PA20R connected to a
TAG McLaren Audio
100P stereo power
(3)
amplifier
remove it.
Always use high-quality, screened cables for your connections.
20
1. TAG McLaren Audio has pre-installed the XLR connectors to make the upgrade
quick and easy
1. A ‘monobloc’ is a single-channel or mono power amplifier
2. You can use OUTPUT 2 instead of OUTPUT 1. They are the same electrically.
OUTPUT 3 is only functional if your PA20R has been fitted with the optional
transformer-coupled and balanced output. See page 19 for details
3. This diagram, and those that follow, are for illustrative purposes only; they are
not to scale and do not show all connections
21
connecting power amplifiersconnecting power amplifiers
left
right
left
right
1
OUTPUT
2
amplifiers
Instead of one stereo power amplifier, you may prefer to use two
monobloc amplifiers (such as our 125M) in conjunction with your
PA20R.
bi-ampingusing mono
With many high-quality loudspeakers, you can make separate
connections to the high- and low-frequency drivers
(1)
. If your
loudspeaker allows it, you can improve the sound further by using
separate amplifiers for high and low frequencies. This may allow
Connect OUTPUT 1 left of the PA20R to the audio input of one of
the monoblocs and OUTPUT 1 right to the audio input of the
other monobloc. Connect each monobloc to a loudspeaker
out
right speaker
hf
lf
outin
1. For the best sound quality we recommend that you place each monobloc near
2223
the loudspeaker it is feeding and use short loudspeaker leads. Use high-quality,
screened phono leads to connect the amplifiers
(1)
.
This diagram shows a
PA20R connected to
left speaker
outin
two TAG McLaren
Audio monobloc 125M
hf
power amplifiers
lf
you to increase the volume without distorting the sound. As each
amplifier is operating in a smaller bandwidth, intermodulation
distortion may also be reduced.
1. The ‘driver’ is the mechanism inside the case of the loudspeaker which actually
makes the sound. Most high-quality loudspeakers have drivers for high, low and
often middle frequencies and the capability to connect them separately.
However, the lack of this facility is not necessarily a sign of low quality (as some
of the finest loudspeakers in the world have proved)
connecting power amplifiers
connecting power amplifiers
24
bi-amping
Connect OUTPUT 1 left and right of the PA20R to the left and right
audio input of one stereo power amplifier and OUTPUT 2 left and
right to the left and right audio input of the other stereo power
amplifier. Connect one power amplifier to your loudspeakers’
high-frequency drivers and the other power amplifier to the
low-frequency drivers
right speaker
hf
lf
1. This simple connection method works with any combination of TAG McLaren
Audio F3 Series amplifiers because they have matched gains. If you want to
connect a different manufacturer’s amplifier, you may need to use an active
crossover or a gain-setting facility. Please contact your retailer for advice if you
wish to do this
(1)
.
out
outin
outin
100P
100P
left speaker
hf
lf
This diagram shows
a PA20R connected
to two TAG McLaren
Audio 100P stereo
power amplifiers
for bi-amping
bi-amping
alternative
arrangement
If you have two matched amplifiers (such as two TAG McLaren
Audio 100Ps), you can connect them as shown here.
This arrangement has the added advantage of allowing you to
place each amplifier close to the loudspeaker it is feeding, thus
enabling you to connect them together with short cables.
Connect OUTPUT left on the PA20R to INPUT left on one of the
100Ps and OUTPUT right on the PA20R to INPUT left on the other
100P. On each 100P connect OUTPUT left to OUTPUT right.
On each amplifier, connect one of the stereo outputs to the highfrequency driver and the other to the low-frequency driver.
out
left speaker
outin
100P
hf
lf
right speaker
outin
100P
This diagram shows an
alternative method of
connecting the PA20R
to two TAG McLaren
Audio 100P stereo
hf
power amplifiers
lf
for bi-amping
25
running in and warming upconnecting power amplifiers
other multiple
amplifier
arrangements
2627
The arrangements described on the previous pages are only
suggestions and do not cover all the connection possibilities for
preamplifiers and power amplifiers.
If you want to expand your audio system, please contact your
retailer who will be happy to discuss your specific requirements.
running in
warming up
TAG McLaren Audio equipment is designed to give optimum
performance for many years.
Just like a high-quality car, the performance of your PA20R will
improve during the first few hours of operation. The electronic
components will then have reached and settled down to nearperfect specification.
Every time you switch on your PA20R, the performance will
improve until the components reach their optimum operating
temperature.
care and maintenancecare and maintenance
fuses
There is a fuse in the power socket on the back of your PA20R.
To change the fuse, unplug the power cable and pull out the fuse
carrier drawer
(1)
.
The fuse carrier contains a spare fuse; this is the first one that
you see when you open the carrier.
service The only service you should do to your PA20R is described on the
left. All other servicing should only be carried out by one of our
authorised service agents.
If service is required, please contact your authorised TAG
McLaren Audio retailer. If your PA20R is still under guarantee,
please refer to the guarantee card which gives you details on
There are no other user-serviceable parts inside the PA20R.
how to claim against the guarantee.
Please keep the original packaging and use it whenever your
cleaning
In order to maintain the appearance of your PA20R, you can
PA20R is transported.
clean it as follows:
before cleaning, always disconnect your PA20R from the AC
supply.
any grease or dirt on the case may be removed with a soft,
lint-free cloth moistened slightly with a mild solution of warm
water and detergent or washing-up liquid. Do not use any
other solutions. Do not use any solvents or abrasives.
take great care not to get any liquid inside the case.
If this happens, you should have your PA20R serviced.
1. You cannot open the fuse carrier drawer while the plug is in the socket
2829
technical data
technical data
30
This section is for those of you who really want to know the ‘insides’ of
your PA20R. You will not miss out on any of the functions or performance
of your PA20R if you choose not to read any further.
input impedance
input level
vs
gain setting
signal to noise
frequency response
(-3 dB)
frequency response
(20 Hz – 20 kHz)
20 kΩ
500 mV at 0 dB (relative to 0.5 V output)
350 mV at 3 dB (relative to 0.5 V output)
250 mV at 6 dB (relative to 0.5 V output)
175 mV at 9 dB (relative to 0.5 V output)
125 mV at 12 dB (relative to 0.5 V output)
90 mV at 15 dB (relative to 0.5 V output)