Plinius M16 User manual

Audio Preamplifier

2

3
CONGRATULATIONS
CONGRATULATIONSCONGRATULATIONS
CONGRATULATIONS on your decision to become the proud owner of this
Plinius M16 Preamplifier.
This manual has been prepared to help you understand the operation of your amplifier, and to provide
information about its design and the variety of ways it may be used.
We have designed and manufactured this preamplifier to reproduce faithfully and accurately, your
favourite music. With a little care and a full understanding of the operating recommendations in this
manual, your Plinius M16 Preamplifier will provide years of high-quality, trouble-free performance.
Serial Number: ..................................................................................
Date of Manufacture: ..................................................................................
Final Test Certified By: ..................................................................................
IMPORTANT: PLEASE TAKE THE TIME TO READ THIS MANUAL
THOROUGHLY BEFORE USING YOUR PREAMPLIFIER.

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Introduction ...................................................................................................................................Page 3
Precautions ...................................................................................................................................Page 5
Preamplifier Features – Front Panel .............................................................................................Page 6
Preamplifier Features – Rear Panel ..............................................................................................Page 8
Preamplifier Features – Remote .................................................................................................Page 10
Installation and Operation ............................................................................................................Page 12
Input/Output Connection ..............................................................................................................Page 13
M16 Features ..............................................................................................................................Page 15
Specifications .............................................................................................................................Page 17
Index ...........................................................................................................................................Page 18
Contact Details ............................................................................................................................Page 19

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Please take special note of the following precautions before operating your new preamplifier:
•This preamplifier operates at hazardous voltage levels. We recommend that any work requiring
removal of the lid or base be referred to a suitably qualified and experienced service technician.
•DO NOT attempt to connect any input of this preamplifier to its own outputs.
•DO NOT earth any output terminal or connect any of these terminals together without following the
instructions in this manual or seeking qualified assistance.
•DO NOT place this preamplifier in any position where liquids or any foreign material may
accidentally enter it.
•DO NOT connect any voltage source, short circuit, earth/ground or appliance (other than suitable
audio power amplifiers) to the preamplifier output terminals.
•DO NOT connect any voltage source, short circuit, earth/ground or appliance (other than suitable
audio source components) to the preamplifier input terminals.

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The front of the Plinius M16 Preamplifier incorporates all the facilities
you will require on a daily basis.
FRONT PANEL LAYOUT SHOWING VOLUME, BALANCE, SOURCE AND RECORD
KNOBS, PHASE AND MUTE SWITCHES, AND DISPLAY LEDS
STANDBY LED
The standby LED indicates when the preamplifier is in standby mode. This LED also lights to show
whenever the remote control is being used to change the volume level.
PHASE SWITCH
Use the phase switch to change the phase response of the Plinius M16 from absolute to inverted 180°.
The LED above the switch will light when the unit is set to inverted phase. If your M16 has the optional
phono stage installed, the opposite applies for the phono circuitry only. In other words, when in phono
the phase LED will light when in absolute phase, but with any other input selected the phase LED will light
when in inverted phase.
MUTE SWITCH
Whenever the Plinius M16 is muted either with the remote control or by using this switch, the LED will
light and the preamplifier outputs will be shorted.
PLINIUS
16
PHONO
C.D.
TUNER
VIDEO
TAP E 1
TAP E 2
RECORDSOURCE
PHONO
C.D.
TUNER
VIDEO
TAP E 1
TAP E 2
PHASE STANDBY MUTE
BALANCE VOLUME

7
SOURCE ROTARY ENCODER
The source selection is controlled electronically, hence the way the source rotary encoder can spin
through a full 360°. An LED will light to show which input is currently selected.
RECORD SOURCE ROTARY ENCODER
The record selection is controlled electronically, hence the way the record rotary encoder can spin
through a full 360°. An LED will light to show which record source is currently selected. There is also a
hidden seventh position where no record source is selected, and no LED will be lit.
BALANCE CONTROL KNOB
The balance control is an ALPS unit that provides accurate alteration of relative gain between the right and
left channels. The balance control has a detent at the centre position.
VOLUME CONTROL KNOB
The volume control is an ALPS motorised unit that will accurately convey the selected source signal to the
line stage of the Plinius M16. When using the remote control to alter the volume level, stab the button to
make small adjustments, or hold the button down to continuously adjust the volume.

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This panel incorporates all the terminals for connecting the input signals from your phono turntable, CD
player, tuner, etc, and the outputs to the power amp and mains supply.
Please remember that your Plinius M16 Preamplifier is a high quality electronic instrument capable of an
exceptional level of performance. Be sure that you understand your system’s requirements fully before
you make any connection to this preamplifier.
REAR PANEL SHOWING INPUT AND OUTPUT TERMINALS, CD SELECT, GROUND
LIFT AND STANDBY SWITCHES, MAINS SWITCH AND MAINS SOCKET.
INPUT TERMINALS
The input terminals of your Plinius M16 Preamplifier are easily accessible along the rear panel. These
standard RCA terminals are for use with single ended signals from line level audio components such as
CD, tuner, video, etc. Also included is one pair of balanced XLR inputs for use with XLR type cables. The
switch above the CD inputs is used to select either single-ended or XLR type input. If you wish to use the
XLR input, the switch above it must be set to XLR also, and the opposite is true for use of the RCA
terminals. Consult your PLINIUS
PLINIUSPLINIUS
PLINIUS dealer for further advice if required.
Note that in ‘line’ configuration (no phono stage installed) all the inputs can be used with normal line level
sources. If the optional phono stage has been installed, do not connect any source other than a suitable
phono turntable to the phono input.
CAUTION
RISK OF ELECTRICAL SHOCK
DO NOT OPEN
CAUTION: TO REDUCE RISK OF
COVER. NO USER SERVICEABLE
PARTS INSIDE. REFER SERVICING TO
QUALIFIED SERVICE PERSONNEL.
CHASS IS
OPEN
STANDBY CIRCUIT
GROUND
C.D.
MAINS FUSE
REPLACE ONLY WITH
SAME TYPE
VIDEO
T
APE 1
IN OUT
T
APE 2
IN OUT
OUTPUTS
PUSH PUSH
RCA XLR
PUSH PUSH
PHONO TUNER C.D.
PLINIUS PRE - AMPLIFIER
SERIAL No. POWER
CONSUMPTION
50/
60
12 0 V / A
VOLTAGE Hz
DESIGNED AND MANUFACTURED IN
NEW ZEALAND BY
AUDIBLE TECHNOLOGIES LTD
P.O. BOX 183 6
PAL MERST O N N ORTH

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OUTPUT TERMINALS
Connections for power amplifiers are provided on the right hand side of the rear panel. Connections are
available for both single ended (RCA type) and balanced (XLR type) cables. Note that the only time the
outputs aren’t ‘live’ is when the preamplifier is in mute or standby.
TAPE OUTPUTS
These RCA outputs are situated next to the tape RCA inputs, and are provided to interface to a pair of line
level recording devices. The position of the record rotary encoder on the front panel determines from
which device a recording is made. These tape outputs are always ’live’ except when standby is selected.
GROUND LIFT SWITCH
This switch allows the signal ground to be disconnected from the chassis. In some installations a hum
loop may exist due to duplicate ground paths from different equipment. Use this switch to remove the
connection from 0V to ground thus allowing some flexibility in your particular set-up.
STANDBY SWITCH
This switch works in conjunction with the remote control to short the outputs and disconnect the inputs.
Use this switch whenever the Plinius M16 is not in use. Note that when in standby the line stage and
power supply is still live, so the internal circuitry will stay at normal operating temperature.
MAINS SWITCH
The heavy-duty rocker switch to the right of the panel turns the Mains/Line Power to the amplifier ON or
OFF. Depress the right hand side of the switch to turn the amplifier on. The amplifier draws a moderately
high current when switched on, so it is not good practice to rapidly turn the Mains switch on and off
repeatedly.
MAINS POWER CORD IEC SOCKET
This connector is where the mains supply cable from your wall connects to the preamplifier. You will
notice that a fuse holder is mounted within this connection, and it holds a mains fuse to provide surge and
overload protection for your preamplifier.
EARTH POST
This is a chassis connected gold-plated earth post for use with certain phono turntables.

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The Plinius M16 Remote provides access to most of the
controls you will require on a daily basis.
REMOTE CONTROL SHOWING FUNCTION BUTTONS.
VOLUME CONTROL
Use these two buttons to control the volume level of the preamplifier. The middle top button increases
volume, while the button directly below it decreases the volume. Stab either button to make fine
adjustments to the volume level. Hold down either button to continually adjust the volume level.
PLINIUS
STANDBY
RECORD PHASE
TUNER
C.D.PHONO
VCR TA P E 1 TA P E 2

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MUTE
Use this button when you require the preamplifier to mute the output from the preamplifier. Pressing the
button again brings the preamplifier back out of mute.
PHASE
The phase of the input signal to the preamplifier is switched from absolute to inverted 180°with each
press of this button.
STANDBY
Standby shorts the outputs of the preamplifier and disconnects the inputs. It is recommended that
whenever the Plinius M16 is left switched on but not in use, the standby function be implemented.
RECORD
The record button toggles the selected recording source for both tape loop outputs. Use this button to
select the source from which you want to record. The seventh hidden position can also be selected using
this button on the remote control.
SOURCE SELECTION
The six bottom buttons labelled Phono through to Tape 2 are used to make active the source from which
you wish to listen to.

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PLACEMENT AND VENTILATION
Ventilation through and around your Plinius M16 Preamplifier should be kept unimpeded, so ensure that
the heat vents (slots in the lid) are not covered or restricted in any way.
The Plinius M16 design incorporates a very high level of mechanical de-coupling of the input and output.
However, it can still be influenced by acoustical feedback in the operating environment. The use of
acoustic cones or a suitably spiked preamplifier stand or table, may further enhance the performance of
this preamplifier. Consult your PLINIUS
PLINIUSPLINIUS
PLINIUS dealer for further advice if required.
MAINS VOLTAGE CONNECTION
Firstly, check that the mains supply voltage printed on the rear of this preamplifier is similar to the mains
supply voltage in your area. If in doubt, please consult your PLINIUS
PLINIUSPLINIUS
PLINIUS dealer.
Mains supply power connection is via the supplied plug-in lead. A standard IEC socket connects the
mains power at the preamplifier end, while a local mains plug is required at the wall end.
The wiring code used inside all Plinius product is:
Green to Earth/Ground
Green to Earth/GroundGreen to Earth/Ground
Green to Earth/Ground
Blue to Neutral
Blue to NeutralBlue to Neutral
Blue to Neutral
Brown to Phase/Live
Brown to Phase/LiveBrown to Phase/Live
Brown to Phase/Live
Should a ‘local’ plug need fitting to the wall end of the lead, ensure that a suitably qualified service
technician wires the plug correctly.
IMPORTANT: DO NOT POWER UP YOUR PREAMPLIFIER UNTIL YOU
HAVE CONNECTED YOUR INPUT/OUTPUTS CORRECTLY
FOR YOUR SYSTEM, (AS EXPLAINED IN THE NEXT
SECTION).

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It is important that you connect your power amplifier/s (outputs) and source components (inputs) to your
Plinius M16 Preamplifier correctly to ensure the preamplifier is not damaged, and sounds its best within
your system. Now that you have read and familiarised yourself with the various connections on the
preamplifier, as covered in previous sections, we will describe in detail the way in which you can connect
the preamplifier to your system.
Connect your phono turntable, CD player, tuner, tape deck, etc, to the corresponding RCA inputs on the
back of the Plinius M16. Make sure you connect the red coded cable to the red RIGHT RCA input, and the
black (or white) cable to the black LEFT RCA input. Also make sure the RCA connectors are a snug fit and
are inserted all the way in. If you are using balanced XLR cables note that only the CD input caters for this
type of connection. Remember to flick the CD selection switch to the XLR position to activate the XLR
circuitry.
Next, connect your power amplifier/s cables to the output sockets. Ensure that you observe polarity on all
cables (red is right, black is left) to ensure correct channel phasing.
RECORDING MUSIC
In order to record music to tape, or some other line level recording device, these devices will need to be
connected to the tape 1 and tape 2 outputs. Set the record rotary encoder on the front panel to the input
you wish to record from, and the preamplifier will now send signal to both tape 1 and tape 2 outputs.
Note that the volume control does not adjust the recording level: this is done at the recording device itself.
TERMINATION QUALITY
Quality of the connections must be examined to ensure that high-performance, trouble-free operation is
enjoyed. Check that all interconnection cables are snug fitting and inserted all the way in. In the case of
balanced XLR sockets, ensure that they click in positively.
PHASING (OR POLARITY)
It is important to achieve good stereo imaging in your listening room. By observing the wiring
instructions above, each preamplifier/power amplifier/loudspeaker combination should be in phase. If
you experience poor stereo image and/or a lack of bass, check that all interconnection cables and
loudspeaker wires have been connected correctly. We recommend that you use one of the easily
obtainable ‘test discs’ to help you ensure both phasing and channel orientation are correct. If in doubt,
consult your PLINIUS
PLINIUSPLINIUS
PLINIUS dealer for advice.

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To achieve a sound performance that is correctly aligned to your room, make sure all of the leads carrying
signals for the RIGHT channel loudspeaker are connected to the RIGHT input/outputs on your power
amplifier/preamplifier/CD player etc. Signals for the LEFT channel should be wired in a similar fashion.
CONNECTING THE MAINS SUPPLY
Now that your Plinius M16 Preamplifier is configured to your system correctly, the mains cable can be
plugged into the IEC socket on the back of the preamplifier. Re-check all interconnection cables are fitted
correctly. Flick the power switch on the back panel to the right. The standby LED will flash for about five
seconds before closing the mute circuit and setting the active input to Phono.
ENABLING THE INPUTS/OUTPUTS
Use either the Standby switch on the rear panel, or the Standby button on the remote to bring the Plinius
M16 out of standby. Press the Mute button, then alter the volume to achieve the sound level you require.
The Phase button can be used to select absolute or inverted 180°phase. Note that either the remote or
the switches/volume knob on the front panel can be used to perform these functions. You can now enjoy
your new Plinius M16 Preamplifier.
WARM-UP PERIOD
You will find that the Plinius M16 will become noticeably ‘warmer’ in sound after being on for a period of
time. We usually recommend waiting at least 72 hours before expecting the best quality of sound
reproduction from your preamplifier. Also, as the Plinius M16 uses very little power while on, we suggest
leaving the unit turned on (but in standby mode while not being used) so that it will always be at it’s sonic
best.

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PHONO CARTRIDGE LOADING ADJUSTMENT
This section onl
This section onlThis section onl
This section only applies if your M16 was purchased with optional
y applies if your M16 was purchased with optionaly applies if your M16 was purchased with optional
y applies if your M16 was purchased with optional phono stage fitted.
phono stage fitted.phono stage fitted.
phono stage fitted. The phono
cartridge load can be adjusted to suit your particular phono cartridge, using two pairs of internal blue
mini-switches.
The M16 mini-switches are factory set to a 47kΩload. Also, switch 1 is set in the on position. This is a
220pF capacitive setting and is usually required for RF suppression. It is not recommended that you turn
switch 1 off.
Disconnect the lead from the IEC socket on your Plinius M16. Carefully remove the lid by undoing the
three cap screws. Locate the blue mini-switch banks to the rear of the smaller phono circuit board (right
side rear). Adjust the settings of the five individual switches (remember to do both channels) to give a
loading required with reference to the table below.
LOAD
REQUIRED
SWITCH NUMBER AND SETTING
1 2 3 4 5 6
LOAD
REQUIRED
SWITCH NUMBER AND SETTING
1 2 3 4 5 6
7.4ΩON ON ON ON ON ON 29ΩON ON ON ON ON
7.5ΩON ON ON ON ON 30ΩON ON ON ON
7.6ΩON ON ON ON ON 31ΩON ON ON ON
7.7ΩON ON ON ON 32ΩON ON ON
8.0ΩON ON ON ON ON 41ΩON ON ON ON
8.1ΩON ON ON ON 43ΩON ON ON
8.2ΩON ON ON ON 45ΩON ON ON
8.3ΩON ON ON 47ΩON ON
8.8ΩON ON ON ON ON 76ΩON ON ON ON
8.9ΩON ON ON ON 82ΩON ON ON
9.0ΩON ON ON ON 90ΩON ON ON
9.1ΩON ON ON 100ΩON ON
9.7ΩON ON ON ON 320ΩON ON ON
9.8ΩON ON ON 470ΩON ON
9.9ΩON ON ON 1kΩON ON
10.0ΩON ON 47kΩON
Now reassemble your Plinius M16.

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PHONO GAIN ADJUSTMENT
This section only applies if your M16 was purchased with optional
This section only applies if your M16 was purchased with optionalThis section only applies if your M16 was purchased with optional
This section only applies if your M16 was purchased with optional phono stage fitted.
phono stage fitted.phono stage fitted.
phono stage fitted. The phono stage
can also be set to high or low gain to suit your phono turntable specifications (high gain is the factory
setting).
Disconnect the lead from the IEC socket on your Plinius M16. Carefully remove the lid by undoing the
three cap screws. Locate the small black phono jumpers to the centre-front of the smaller phono circuit
board (right side rear). The gain can now be adjusted (remember to do both channels) noting that high
gain is set with jumpers to the front position, and low gain is set with the jumpers towards the rear of the
preamplifier. Now reassemble your Plinius M16.
TAPE LOCKOUT PROTECTION
On most tape decks, any signal recorded is sent to the tape outputs so that the signal level of the
recording can be monitored. Should the user accidentally try to record the tape decks own output,
feedback howl usually results. To prevent this the Plinius M16 Tape Lockout feature will short the outputs
of tape 1 when tape 1 is selected as a record source. The same occurs with tape 2 also.
LED BRIGHTNESS CONTROL
Your Plinius M16 has an internal LED brightness control that will adjust the front panel LED’s. A small flat
bladed screwdriver can be used to adjust the brightness. The LED brightness control is a small multi turn
potentiometer and is located on the front of the main circuit board within the top cavity of the amplifier,
and is labelled VR3. Make sure you adjust the correct potentiometer, and remember to remove the mains
supply from the amplifier before making any adjustments.
REMOTE CONTROL
Your Plinius M16 preamplifier is supplied with an extruded aluminium 12-button remote control. Use of
this remote is described in the ‘Preamplifier Features – Remote’ section. Two AAA batteries power the
remote, and these are replaced by removing the four button head screws holding the base in position.
Replace the two batteries, taking care to refit the new ones with correct polarity.
MAINS/LINE FUSE
A Mains/Line fuse is fitted within the IEC socket on the rear of the preamplifier. A small drawer at the
bottom of this socket may be removed (after the IEC plug is removed) by levering it out with a flat blade
screwdriver. The fuse fitted should be rated at no greater than 5 amp normal blow.

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SF
FF
FREQUENCY
REQUENCYREQUENCY
REQUENCY R
RR
RESPONSE
ESPONSEESPONSE
ESPONSE:
:::Phono RIAA and Line Inputs 20Hz to 20kHz ±0.2dB.
SD
DD
DISTORTION
ISTORTIONISTORTION
ISTORTION:Typically <0.05% THD at rated input level.
SH
HH
HUM
UMUM
UM & N
& N& N
& NOISE
OISEOISE
OISE:
:::Phono -70dB, Line Inputs -80dB at rated input level, A Weighted.
SI
IIINPUT
NPUTNPUT
NPUT S
SS
SENSITIVITY
ENSITIVITYENSITIVITY
ENSITIVITY F
FF
FOR
OROR
OR R
RR
RATED
ATEDATED
ATED O
OO
OUTPUT
UTPUTUTPUT
UTPUT:
:::Phono 500µV, Line Inputs 145mV RMS.
SI
IIINPUT
NPUTNPUT
NPUT I
IIIMPEDANCE
MPEDANCEMPEDANCE
MPEDANCE:
::
: Phono user selectable, Line Inputs 50kΩ.
SR
RR
RATED
ATEDATED
ATED O
OO
OUTPUT
UTPUTUTPUT
UTPUT L
LL
LEVEL
EVELEVEL
EVEL:
::
: 500mV RMS into 10kΩor higher.
SO
OO
OUTPUT
UTPUTUTPUT
UTPUT S
SS
SOURCE
OURCEOURCE
OURCE I
IIIMPEDANCE
MPEDANCEMPEDANCE
MPEDANCE:
::
: Typically 200Ω.
SH
HH
HEIGHT
EIGHTEIGHT
EIGHT:
::
: 130mm (5")
SW
WW
WIDTH
IDTHIDTH
IDTH:
::
: 490mm (19 1/4")
SD
DD
DEPTH
EPTHEPTH
EPTH:
::
: 340mm (13 1/2")
SW
WW
WEIGHT
EIGHTEIGHT
EIGHT:
::
: 9.5kg (21lbs)

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Balance Control..............................................................................................................................Page 7
Date of Manufacture .......................................................................................................................Page 3
Front Panel Layout..........................................................................................................................Page 6
Front Panel Switches......................................................................................................................Page 6
Fuse Protection ............................................................................................................................Page 16
Ground Lift Switch..........................................................................................................................Page 9
IEC Power Connector.............................................................................................................Pages 12,14
Input Terminals .......................................................................................................................Pages 8,13
Mains/Line Fuse...........................................................................................................................Page 16
Mains Supply Connection.............................................................................................................Page 14
Mains Switch .................................................................................................................................Page 9
Output Terminals.....................................................................................................................Pages 7,12
Phase Function .......................................................................................................................Pages 6,11
Phasing........................................................................................................................................Page 13
Phono Features .....................................................................................................................Pages 15,16
Phono Inputs..................................................................................................................................Page 8
Placement............................................................................................................................... Pages 5,12
Rear Panel Layout...........................................................................................................................Page 8
Remote Control .....................................................................................................................Pages 10,16
Safety Precautions..........................................................................................................................Page 5
Serial Number................................................................................................................................Page 3
Standby Function ....................................................................................................................Pages 9,11
Tape Outputs..................................................................................................................................Page 9
Tape Lockout................................................................................................................................Page 16
Terminations ................................................................................................................................Page 12
Ventilation....................................................................................................................................Page 13
Volume Control .......................................................................................................................Pages 7,10
Warm-Up Period ..........................................................................................................................Page 14
XLR Connections............................................................................................................................Page 8

19
All operational, technical and descriptive material published here is subject to change at any time without
notice. For further product information or queries, please contact us at the address below.
PLINIUS
PLINIUSPLINIUS
PLINIUS products are designed and manufactured by:
Audible Technologies Ltd.
Audible Technologies Ltd.Audible Technologies Ltd.
Audible Technologies Ltd.
P.O. Box 18
P.O. Box 18P.O. Box 18
P.O. Box 1836
3636
36
Palmerston North
Palmerston NorthPalmerston North
Palmerston North
New Zealand
New ZealandNew Zealand
New Zealand
Phone:
Phone:Phone:
Phone: [phone]
Facsimile:
Facsimile:Facsimile:
Facsimile: 64 6 354 8586
Email:
Email:Email:
Email: [email protected]
Internet:
Internet:Internet:
Internet: www.pliniusaudio.com
©2000 Audible Technologies.