Introduction

The Myryad MA 120, 240 and 360 Power Amplifiers have been designed to offer a combination of high quality sound reproduction and simple yet elegant styling. They can be used to provide power for high quality stereo systems when partnered by a suitable preamplifier such as Myryad’s MP 100, or with a Myryad integrated amplifier in bi-amp or tri-amp systems. They can also be used, in combination (e.g. one MA 240 Stereo Power Amplifier plus one Myryad MA 360 Three Channel Power Amplifier), to power a full-surround music or Home Cinema sound system of the highest quality.

The MA 120 and MA 360 have unbalanced line inputs plus directly linked line outputs, all on RCA phono sockets.

The MA 240 also has unbalanced line inputs plus directly linked line ouputs, all on RCA phono sockets but in addition it has balanced line inputs on professional quality 3-pin XLR sockets. Furthermore, the two amplifier channels may be switched to bridged-mono mode for increased power output into a single 8W loudspeaker using a rear panel switch.

All Myryad M-Series Power Amplifiers may be controlled remotely via the My-Link communications bus when used with other Myryad M-Series products. The My-Link allows remote control of standby and mute functions. In addition to this, the MA 240 and MA 360 power amplifiers may be switched into or out of standby remotely using their DC trigger inputs.

MA 120 applications include:

  • Stereo operation, delivering 2 x 60 watts into 8W loudspeakers
  • One MA 120 with an MI 120 Integrated Amplifier in a bi-amplifier system
  • Two MA 120s with an MP 100 Preamplifier in a bi-amplifier system
  • Three MA 120s with an MP 100 Preamplifier in a tri-amplifier system
  • Up to ten MA 120s and one MI 120 or MP 100 in a multi-room system

    MA 240 applications include:

  • Stereo operation, delivering 2 x 120 watts into 8W loudspeakers
  • High power stereo operation with two MA 240s – able to deliver 2 x 400 watts into a minimum 8W load
  • Stereo bi-amplifier operation with two MA 240s, each delivering 2 x 120 watts into 8W loudspeakers
  • Use in conjunction with the MA 360 Three Channel Power Amplifier, delivering five channels at 120 watts into 8W in Home Cinema systems of the highest quality

    MA 360 applications include:

  • Use in conjunction with the MA 240 Stereo Power Amplifier, delivering five channels at 120 watts into 8W in Home Cinema systems of the highest quality.

    This Owner’s Manual describes all three power amplifiers. Where the text applies to only one or two of the amplifiers the applicable model number(s) appear in the paragraph heading. Where no model number is specified in the paragraph heading the text applies to all power amplifiers.

    Installation and Safety Notes

    This amplifier generates a modest amount of heat and thus requires ventilation. Do not place it on a rug or other soft surface into which it could sink, obstructing the air inlets in its underside. Do not allow papers or cloth to obstruct the ventilation grille in the top cover. The amplifier should not be installed in a built-in situation such as a bookcase or cabinet that may impede the flow of air. If the amplifier is moved shortly after operation take care not to touch the heatsinks, which are accessible from below, as they may be very hot. The amplifier is designed for use in moderate climates.

    CAUTION:To prevent a fire or shock hazard, do not permit this product to become wet or expose it to dripping or splashing. Do no place objects filled with liquid, such as vases, on the amplifier. If liquid is accidentally spilled on it, immediately shut off its power at the wall socket and unplug the AC power cord. Allow sufficient time for complete evaporation to occur before operating the amplifier again. If the liquid is anything but water and/or alcohol, a qualified service technician should examine the amplifier before it is used again.

    Do not place naked flames, such as lighted candles on this product.

    Do not remove the cover, or attempt to modify or repair the amplifier yourself. Refer all servicing to a qualified technician.

    Accessories – Your Myryad Power Amplifier is supplied complete with the following accessories:

    MA 120, MA 240 and MA 360

  • Separate mains power cord to suit country of sale.

    MA 240 only

  • Two “U”-shaped gold-plated XLR jumper links. Supplied inserted into the BALANCED input sockets. {If you remove these links from the amplifier store them in a safe place as they may be needed in the future.}

    REAR PANEL CONNECTIONS

    For pictures of the rear panels of all three amplifiers, click here.

    POWER inlet

    Before making any connection, check that the mains voltage setting printed on the rear panel is the same as your local mains supply.

    Plug the female (socket) end of the power cord into the power inlet on the rear of the amplifier. Plug the male (plug) end of the cord into a "live" wall socket or a suitable heavy-duty extension cable.

    UK version: The mains plug is supplied fitted with a 5A fuse. It should only be replaced with a fuse of the same rating (5A) which complies with BS1362.

    Instructions for re-wiring a UK plug can be found here.

    POWER switch

    Press one side of this rocker switch (the side nearer the edge of the rear panel) to switch amplifier ON and the other side (towards the speaker terminals) to switch it OFF. When the POWER switch is in the OFF position all power is disconnected from the amplifier. In this condition the amplifier cannot be powered up from the front panel or the My-Link (or remote trigger if present). When the POWER switch is in the ON position (and the power cord correctly inserted and plugged in to a live wall socket) the amplifier will power up in standby mode (see below).

    It is recommended that the POWER switch be turned OFF if the amplifier is not going to be used for an extended period of time.

    MY-LINK input/output

    When this Power Amplifier is used in a system with other Myryad M-Series products all may be joined together via the My-Link. This will allow the different products to be remotely controlled via the infra-red receiver on, for example, an MP 100 Preamplifier. My-Link offers two benefits. First, only the MP 100 Preamplifier infra-red receiver needs to be in "line-of-sight" from the remote handset. Second, the My-Link allows remote control of some Myryad products which do not have their own infra-red receiver, such as the Myryad Power Amplifiers.

    When joined via the My-Link, the Power Amplifier will respond to STANDBY and MUTE operations on the MP 100 Preamplifier i.e.: if both the MP 100 Preamplifier and the Power Amplifier are in STANDBY, then switching the MP 100 Preamplifier out of standby will also bring the Power Amplifier out of standby. In this way the MP 100 + MA 240 (or MA 120) can be operated with the same ease as an integrated amplifier. If Power Amplifiers are being used in a bi-amp or tri-amp system all the amplifiers may be My-Linked so that they can be controlled as one from the Myryad preamplifier.

    N.B: Manually switching the Power Amplifier into standby will not switch the MP 100 Preamplifier into standby.

    MA 240 and MA 360 only: when the My-Link is connected it is recommended that no connection be made to the REMOTE TRIGGER input (see below).

    REMOTE TRIGGER control input/output (MA 240 and MA 360 only)

    If the MA 240/360 is being used in a system without a Myryad M-Series preamplifier, processor or integrated equipped with My-Link, the REMOTE TRIGGER input may be used to allow the MA 240/360 to be remotely switched into or out of STANDBY.

    If your preamplifier or processor has a TRIGGER output which delivers a DC trigger signal when the unit is switched on (or out of standby) then it can be linked to the MA 240/360 to switch the MA 240/360 out of/into standby also. A lead must be used which is fitted with a 3.5mm mini-jack plug to connect to the MA 240/360’s REMOTE TRIGGER input socket. The lead must be wired according to the rules below:

    1. Connector to MA 240/360 REMOTE TRIGGER input: 3.5mm mini-jack plug
    2. Jack plug wiring: sleeve negative, tip positive DC, 4.5V to 24V
    3. Nominal loading of MA 240/360 REMOTE TRIGGER input: 2200W
    4. Operation: TRIGGER voltage change from 0 to +ve: Amplifier switched from standby to active
    5. TRIGGER voltage change from +ve to 0: Amplifier switched from active to standby

    IF YOU ARE IN ANY DOUBT ABOUT MEETING ANY OF THESE CRITERIA, OR PREPARING A SUITABLE LEAD, ASK YOUR DEALER OR INSTALLER TO HANDLE THIS FOR YOU.

    Note: If the TRIGGER input is active when the rear panel POWER switch is turned ON, then the amplifier will not power up into standby mode as usual. It will power up immediately into its “active” state – with its normal power-on mute delay (see below).

    The REMOTE TRIGGER output is wired directly to the input. Using this output, further MA 240/360s, or other products, may be connected from a single trigger source without needing any special adaptors.

    LOUDSPEAKER outputs

    The loudspeaker outputs are capable of driving all loudspeakers with rated impedances in the range 4W to 16W (except the MA 240 in Bridged-Mono Mode – see below) The loudspeaker terminals are high-current binding-posts, coded red and black. The terminals on the left side of the amplifier (viewed from the front) and marked "L" should be wired to the left hand loudspeaker. Those on the right, marked "R", should be wired to the right hand loudspeaker.

    CAUTION: The red terminals are marked with a hazard symbol to indicate that they can be live. Read all the loudspeaker wiring instructions carefully. It is recommended that ready-made leads be used where possible.

    For correct stereo imaging it is important that the two loudspeakers are wired "in phase". To ensure correct phasing wire the black (-) terminal on the amplifier to the black or "-" terminal on the loudspeaker. The red (+) terminal on the amplifier should be wired to the red or "+" terminal on the loudspeaker.

    The loudspeakers should be positioned as recommended by the loudspeaker manufacturer. The two loudspeakers should always be placed at equal distances from the main listening position and usually spaced a similar distance apart. It is generally best to keep the loudspeakers away from room corners and many loudspeakers work best away from all walls.

    MA 240 only: when the MA 240 is switched to BRIDGED-MONO mode, only the red speaker terminals are used. No connection should be made to either of the black terminals. For correct phasing connect the Left hand red (+) terminal on the amplifier to the red or "+" terminal on the loudspeaker and connect the Right hand red (+) terminal on the amplifier to the black or "-" terminal on the loudspeaker. Each amplifier and loudspeaker should be connected in the same way.

    When the MA 240 is switched to BRIDGED-MONO mode, each amplifier drives into only half the speaker impedance so loudspeakers rated at less than 8 W impedance must not be used.

    MA 360 only: the three channels in the MA 360 may be assigned in a variety of ways in Home Cinema systems. The two most common are: channels 1 and 2 for left surround and right surround, with channel 3 for front centre (using an MA 240 for left front and right front) or, channels 1,2 and 3 for left front, centre and right front (using an MA 240 for left surround and right surround). In each case make sure all loudspeakers are wired “in phase” as described above.

    Line Inputs – NORMAL (Unbalanced)

    The NORMAL “unbalanced” line inputs can be driven from the line outputs of any good quality preamplifier (such as the Myryad MP 100 or any other suitable line level source. High quality phono-to- phono (RCA-to-RCA) interconnects should be used.

    MA 240 only: when using the NORMAL line inputs the two XLR jumper links (“U”- shaped gold-plated links) must be inserted into the BALANCED input sockets on each channel (between pins 1 and 3 as indicated on the rear panel). The MA 240 is always shipped in this condition. Failure to insert these links will result in reduced input sensitivity and possibly some background hum, but it will not endanger the amplifier.

    Line Outputs – NORMAL (Unbalanced)

    Each channel’s line output is directly connected to its line input – without buffering. The line output allows power amplifiers to be “daisy-chained” so that more complex systems may be built. For a more detailed discussion of bi-amping, tri-amping and multi-room installations please refer to the Appendix. Only unbalanced line outputs are fitted.

    Line Inputs – BALANCED (MA 240 only)

    The BALANCED line inputs can be driven from the balanced line outputs of any good quality stereo preamplifier (such as the Myryad MP 100) or any other suitable line level source. High quality XLR-to-XLR balanced interconnects should be used.

    In order to use the BALANCED line inputs the two XLR jumper links (the “U”-shaped gold-plated links plugged into the BALANCED input sockets) must first be removed. Take care of these links and store them in a safe place. They will be needed again if the amplifier’s unbalanced inputs are to be used.

    BRIDGED MONO Switch (MA 240 only)

    The MA 240 is shipped with this switch in the STEREO position, with the button pressed in almost flush with the rear panel. In this mode the MA 240 operates as a conventional stereo amplifier as described above.

    If the button is pressed to release it to the “out” position, the MA 240 is switched to BRIDGED MONO mode. The amplifier then operates as a single channel “mono” amplifier to drive just one loudspeaker, but at a much higher power level (up to 400 watts into 8W). A second power amplifier is needed for stereo operation in this mode.

    When operated in BRIDGED MONO mode the following rules must be applied:

  • Connect the line input signal to the LEFT channel input, either NORMAL (unbalanced) or BALANCED.
  • Connect the loudspeaker between the two RED (“+”) loudspeaker output terminals, with the red or “+” terminal of the speaker connected to the MA 240’s Left “+” terminal and the black or “-” terminal of speaker connected to the MA 240’s Right “+” terminal.

    CAUTION: When operating the MA 240 in BRIDGED MONO mode the minimum rated loudspeaker impedance is 8 W

    FRONT PANEL CONTROLS

    For pictures of the front panel, click here.

    STANDBY SWITCH

    When the amplifier is plugged into a live wall socket and the POWER switched is turned ON, it will power up in "standby" mode and the LED (Light Emitting Diode) in the STANDBY button will glow red. In this mode the internal circuitry of the amplifier is powered up, but disabled so that it consumes very little power and is isolated by relays at its outputs.

    When the STANDBY button is pressed the amplifier circuitry will be activated and the LED will flash green. After a few seconds delay the loudspeaker outputs will be connected to the amplifier and the LED in the STANDBY button will glow green continuously. (The mute delay in the MA 120 is about 4 seconds, but in the MA 240 and 360 it is about 8 seconds to allow for the longer settling time of the larger amplifiers’ circuits.)

    Please note: When the power amplifier is remotely activated from another unit, there will be a brief delay between the closing of the output relays of the two units. This is normal and no cause for concern.

    When the STANDBY button is pressed again the amplifier will be returned to standby mode. The LED in the STANDBY button will change back to red.

    CAUTION: When in standby mode the internal circuitry of the MA 120, 240 or 360 is still live, so all safety precautions MUST be followed.

    LOUDSPEAKER OUTPUT PROTECTION AND MUTING

    When the amplifier is in standby mode the loudspeaker output terminals are isolated from the amplifier by a high quality relay. When the amplifier is first switched on from standby mode the loudspeaker outputs remain disconnected for a few seconds to allow the internal voltage levels to settle. The loudspeaker outputs are immediately disconnected again when the amplifier is switched back into standby mode.

    The same loudspeaker mute relay is used to protect both the amplifier and your loudspeakers against possible damage. If any one of a number of fault modes is detected (loudspeaker outputs short circuit, amplifier overheating, amplifier DC fault) the loudspeakers will be disconnected from the amplifier to protect both. In the case of a short circuit or DC fault the loudspeakers will be re-connected after a few seconds, but will be disconnected again if the fault persists. If overheating has caused the protection system to operate, then it will take some time for the heatsinks to cool sufficiently to allow the loudspeakers to be re-connected (probably between five and fifteen minutes depending upon the room temperature and ventilation). The amplifier will cool more quickly if it is switched to standby mode, or if the POWER is switched OFF.

    Trouble Shooting – For help trouble shooting, try the guide. You can also look at the FAQ section. If you still have questions, please email Myryad for technical support.

    Specifications – For specifications, click here.

    Systems Building – For information regarding system building with the MP 100 Pre-Amplifiers, MI 120 or MA 240 Integrated Amplifiers and MA 120, MA 240 and MA 360 Power Amplifiers, have a look at the Myryad Technical Note addressing this subject.