Plinius M16 User manual

Audio Preamplifier

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.

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

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.

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

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

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.

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

APE 1

IN OUT

APE 2

IN OUT

OUTPUTS

PUSH PUSH

RCA XLR

PUSH PUSH

PHONO TUNER

C.D.

PLINIUS PRE - AMPLIFIER

SERIAL No. POWER

CONSUMPTION

50/

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

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.

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

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.

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).

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.

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.

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.

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.

FREQUENCY

REQUENCYREQUENCY

REQUENCY R

RESPONSE

ESPONSEESPONSE

ESPONSE:

:::Phono RIAA and Line Inputs 20Hz to 20kHz ±0.2dB.

DISTORTION

ISTORTIONISTORTION

ISTORTION:Typically <0.05% THD at rated input level.

HUM

UMUM

UM & N

& N& N

& NOISE

OISEOISE

OISE:

:::Phono -70dB, Line Inputs -80dB at rated input level, A Weighted.

IIINPUT

NPUTNPUT

NPUT S

SENSITIVITY

ENSITIVITYENSITIVITY

ENSITIVITY F

FOR

OROR

OR R

RATED

ATEDATED

ATED O

OUTPUT

UTPUTUTPUT

UTPUT:

:::Phono 500µV, Line Inputs 145mV RMS.

IIINPUT

NPUTNPUT

NPUT I

IIIMPEDANCE

MPEDANCEMPEDANCE

MPEDANCE:

: Phono user selectable, Line Inputs 50kΩ.

RATED

ATEDATED

ATED O

OUTPUT

UTPUTUTPUT

UTPUT L

LEVEL

EVELEVEL

EVEL:

: 500mV RMS into 10kΩor higher.

OUTPUT

UTPUTUTPUT

UTPUT S

SOURCE

OURCEOURCE

OURCE I

IIIMPEDANCE

MPEDANCEMPEDANCE

MPEDANCE:

: Typically 200Ω.

HEIGHT

EIGHTEIGHT

EIGHT:

: 130mm (5")

WIDTH

IDTHIDTH

IDTH:

: 490mm (19 1/4")

DEPTH

EPTHEPTH

EPTH:

: 340mm (13 1/2")

WEIGHT

EIGHTEIGHT

EIGHT:

: 9.5kg (21lbs)

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