CONGRATULATIONS on your decision to become the proud owner of this Plinius SA-Reference Power Amplifier. 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 amplifier to reproduce faithfully and accurately, your favourite music.
DESIGN PHILOSOPHY From a distance you can see that the design of the Plinius products is more than an applied styling exercise to the front panel. We have started from the ground up to produce a casing for our electronics that is unrivalled in its physical strength and visual simplicity.
CONTENTS Introduction .................................................................................................................................... Page 3 Precautions ..................................................................................................................................... Page 5 Amplifier Features - FRONT PANEL .................................................................................................. Page 6 Amplifier Features - REAR PANEL ..........................
PRECAUTIONS Please take special note of the following precautions before operating your new amplifier: • The Plinius SA-Reference Power Amplifier can be operated in mono mode delivering up to 1000 watts into 8 ohms. This amplifier is also capable of a very large peak current delivery. • The Plinius SA-Reference Power Amplifier operates in Class A. It is capable of generating temperatures that could have an adverse effect on other equipment, furniture etc.
AMPLIFIER FEATURES – FRONT PANEL MUTE CLASS A FRONT PANEL LAYOUT SHOWING MUTE AND BIAS SWITCHES MUTE SWITCH It is not recommended practice to interfere with the input cables while the amplifier is switched on and connected to the loudspeakers, so a Mute button is fitted to interrupt the input signal. This allows you to connect and disconnect the input cables without the necessity of turning the amplifier off.
CLASS A: This position provides Class A bias to the output stage therefore ensuring the optimum performance of the amplifier during all listening events. Class A amplifiers run hotter than Class AB amplifiers, hence our specially designed and distinctive heat sinks. Operating the amplifier in Class A necessitates two precautions that should be observed. 1. On switching to Class A, the temperature of the amplifier will quickly increase and the amplifier will become quite hot.
AMPLIFIER FEATURES – REAR PANEL This panel incorporates all the terminals for connecting the input signals from your preamplifier, and output to the loudspeakers, and mains supply. A reasonable understanding of this amplifier’s operation and a logical approach should ensure that you are able to make all connections with ease. Please remember that your Plinius SA-Reference Power Amplifier is a high quality electronic instrument capable of an exceptional level of performance.
INPUT TERMINALS Input terminals for your Plinius SA-Reference Power Amplifier are easily accessible and fitted to the top centre area of the rear panel. A brief summary of connection possibilities is listed below, while a more detailed explanation follows later in this instruction manual. RCA INPUTS LEFT & RIGHT: These standard RCA terminals are for use with unbalanced signals from most signal sources such as audio preamplifiers.
The ACS switch options are: RCA STEREO: This option provides a stereo output via both left and right output channels from a stereo signal connected to both left and right input RCA inputs. RCA BRIDGED MONO: This option configures your amplifier to drive one loudspeaker from one unbalanced signal fed to the RIGHT RCA input.
OUTPUT TERMINALS - BRIDGED/MONO In bridged/mono modes, the loudspeakers utilise only the positive (+) outputs of your Plinius SAReference. In this configuration power output to the loudspeakers is dramatically increased (around four times as much), and is commonly used in conjunction with another amplifier for amplification of each channel from the preamplifier.
INSTALLATION AND OPERATION PLACEMENT AND VENTILATION Your Plinius SA-Reference is designed to operate at a moderately high temperature, even more so when used in Class A. The ideal location is on a rigid stand or floor mounted away from direct contact with any temperature sensitive materials or deep pile carpets. The flow of air around the amplifier should also be kept unimpeded, so ensure that the heat sinks (cooling fins) are not covered or restricted in any way to ensure adequate ventilation.
INPUT/OUTPUT CONNECTION RIGHT INPUTS LEFT INPUTS RCA STEREO RIGHT OUTPUTS + XLR BALANCED MONO RCA BRIDGED MONO XLR STEREO ALL MONO/BRIDGE OPTIONS USE RIGHT INPUT AND LEFT + RIGHT+ OUTPUTS ONLY AMPLIFIER CONFIGURATION SELECTOR REFER TO OWNERS MANUAL FOR USAGE INSTRUCTIONS + LEFT OUTPUTS + + REAR PANEL SHOWING LOCATION OF INPUT/OUTPUT TERMINALS It is important that you connect your loudspeakers (outputs) and preamplifier (inputs) to the Plinius SAReference Power Amplifier correctly to ensure the
RCA STEREO Connect your preamplifier or input signal to the two RCA inputs at the top of the amplifier back panel. 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. Next connect your loudspeaker wires to the output posts on either side of the rear panel.
XLR BALANCED MONO As with RCA Bridged Mono, this option configures your amplifier to drive one loudspeaker, but from one balanced line input connected to the RIGHT XLR Input. In balanced mono mode the only input made to your preamplifier is to the RIGHT channel XLR input. The LEFT channel XLR input is not connected. Next your loudspeakers are connected to both positive (+) channel output terminals.
PHASING (OR POLARITY) It is important to achieve good stereo imaging in your listening room. By observing the wiring instructions above, each Power Amplifier/loudspeaker combination should be in phase. If you experience poor stereo image and/or a lack of bass, check that the loudspeaker wiring has 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.
SA-REFERENCE FEATURES ERROR DETECTION The Plinius SA-Reference Power Amplifier has in-built error detection. This will function under the following conditions: • • When the amplifier is overdriven/clipped If any internal fuse is damaged Should either of these circumstances arise the amplifier will disconnect both channels and mute the input. This condition will remain until the input signal level is reduced or the damaged fuse replaced.
LED BRIGHTNESS CONTROL Your Plinius SA-Reference has an internal LED brightness control that will adjust all three 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.
LOUDSPEAKER SELECTION Your Plinius SA-Reference Power Amplifier is designed for use with high fidelity loudspeakers. It should not be used to operate any other type of appliance or equipment. Choice of loudspeakers is one of personal taste, providing the chosen loudspeakers are suitable for use with your amplifier. Be certain that your loudspeakers can handle most of the rated output power of this amplifier.
WHY CLASS A IS BETTER Class A has always been regarded as the perfect operating mode for audio amplifiers. Many leading amplifier designers and manufacturers world wide recognise that a well designed Class A circuit has inherently lower distortion than any other design. Class A circuit topology is one in which the total current the amplifier is capable of delivering, is kept flowing in the circuit regardless of demand.
SPECIFICATIONS 300-WATTS RMS PER CHANNEL INTO 8 OHMS. 450-WATTS RMS PER CHANNEL INTO 4 OHMS. BOTH CHANNELS DRIVEN FROM 20Hz TO 20kHz AT 0.05% TOTAL HARMONIC DISTORTION. MONO OUTPUT: 1000 Watts RMS 20Hz to 20kHz into 8 ohms (Mono). DYNAMIC HEADROOM: 1dB or greater at 8 ohms with music. FREQUENCY RESPONSE: 20Hz to 20kHz ±0.2dB. 0dB at 0Hz and -3dB at 70kHz. DISTORTION: Typically <0.05% THD at rated power. 0.1% THD and IM worst case prior to clipping. VOLTAGE SWING: 130Vpp per channel.
INDEX ACS (Amplifier Configuration Selector) ........................................................................................ Page 9 Balanced Signal ........................................................................................................................ Page 10 Bias Class A .........................................................................................................................Pages 7,20 Bias Class AB ...................................................................
CONTACT DETAILS 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 products are designed and manufactured by: Plinius Audio Ltd. P.O. Box 1836 Palmerston North New Zealand Phone: Facsimile: Email: Internet: 64 6 354 8583 64 6 354 8586 info@pliniusaudio.com www.pliniusaudio.com ©2005 Plinius Audio Ltd.
