clayton audio M-300 User manual

Clayton Audio
M-300 Monaural power amplifier
Truly Remarkable Amplifiers.

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Clayton Audio
M-300 Monaural power amplifier
Introduction
Congratulations on your purchase of the Clayton Audio M-300
monobloc amplifiers! Your M300s were made to sound good and to
perform as well as the very best amplifiers on the market. They are a
high-current design that can drive the most demanding speaker loads.
These power amplifiers were designed to produce reference-quality
sound with all the excitement and elegance of live music. The M-300s
were handmade in the USA after years of careful design and testing.
Properly used and installed, these amplifiers will provide you with many
years of trouble-free, high-quality amplification. We hope that you will
take the time to read and look through this owner’s manual before
operating the M-300.

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Installation
Please unpack the amplifier carefully in accordance with the enclosed
instruction card. Each monaural power amplifier weighs 87 pounds so
we urge reasonable caution in handling to avoid injury. Please save all
packing materials for future use. Should you need to ship your
amplifier to us, only the original shipping cartons will be acceptable.
Other packing methods might result in serious damage to your precision
amplifiers.
Inspect your amplifier carefully to make sure that it has suffered no
damage in shipping. Consult your dealer if you have any questions.
Do not stack any equipment on top of the amplifiers. Always remember
to power-off and disconnect the amplifiers when moving or handling
them.
Unpacking your new amplifiers
The amplifers are heavy. Use caution when lifiting them after
removing all packing material, or use a friend to assist with lifting
and amplifer placement in your home. Save all packing materials in

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the box. Below are photos of the series of steps used to unpack the
amplifier. Please note that we use a special metal protector
blocking the fuse holders, 12 volt trigger switch and remote control
port. We recommend leaving this metal strip on the rear panel until
removal is necessary.
Carefully cut through the taped top center and top sides
Lift the cardboard flap exposing the top layers of foam and remove.

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Remove the Front Faceplate foam.

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Remove the side foam, power cord and antistatic plastic wrap

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Carefully remove the antistatic plastic and protective material
This is a photo of the front faceplate cleared after removal of foam.

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Carefully lift the amplifier with the rear protection attached to remove
later.
Once the amplifier is placed near the final position, remove the rear
panel protection and remove the tape from the connectors.

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Operation
The Clayton Audio M-300 monoblocs are high-performance class A
amplifiers, conservatively rated at 300 watts per channel into 8 ohms.
They are a no-compromise, wide-bandwidth design which should drive
virtually any high-end speaker load with relative ease. Because the
Clayton Audio M-300s are a class A design, they will run very hot in
normal operation. Make sure to place them in a well-ventilated
location on a stable support. Be careful about touching the tops of the
heat sinks when in operation. Depending on the AC line voltage the
high-bias setting will run at a temperature up to 55 degrees Fahrenheit
above the room temperature. The low-bias setting will only run about 40
degrees above room temperature. Under casual listening conditions, the
low-bias setting will be virtually indistinguishable from the high-bias
setting and will not make the amplifier run as hot. The bias switch can
be set to high when listening critically or at high volume levels. Since the
amplifier is very stable, you can switch between the two bias positions at
any time, even while the amplifier is in operation. See photo below.

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The Power Switch in On and the Bias Mode is on High Bias.
Each Clayton Audio M-300 has three fuses, easily accessible from the
rear panel. All fuses are 5 amp, Fast Blow (FB) types which must be
replaced with fuses of the same value. To examine and replace a fuse,
make sure the amplifier is powered down, remove the fuse protector
plate and then simply push in the rear knob (nut) of the fuse and turn it
counter-clockwise to release. This is the only repair that the user should
attempt to make. If you are experiencing any problems with the
amplifier that cannot be solved by replacing the fuses, call your Clayton
Audio Dealer immediately. The toggle switch is the 12 volt trigger. The
default position is in the down or “OFF” mode.
DO NOT OPEN THE AMPLIFIER if there is any problem. You should
contact your Clayton Audio dealer immediately. Any attempt to open
and/or tamper with the M-300 amplifiers will void the warranty
immediately.

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Each Clayton Audio M-300 has two high-quality German WBT binding
posts that accept either spade lugs or banana plugs for connection to
the speaker wires. Make sure to connect the positive (+ usually red)
speaker connector to the + connection and the negative (- usually black)
speaker connector to the - connection on both the right amplifier and
the right speaker. Do the same for the left amplifier and speaker.
Each amplifier also has a precision German WBT XLR input jack for True
Balanced™ operation. Connect the audio source’s right output jack to
the right monobloc’s XLR input jack using a good quality interconnect.
Do the same for the left monobloc amplifier. The balanced pin-out
configuration is: Pin 1=Ground; Pin 2=Positive (Hot); Pin 3=Inverted
180°. Our ground is to the chassis as well as the ground through the AC
power cord. There is a gold plated knurled ground connector for
assisting with potential ground loop problems with preamplifiers or
other equipment that utilizes Single Ended or quasi balanced topology.
Design Concept
The Clayton Audio M-300’s are high current differential True Balanced™
amplifiers using class A design in both the driver and output stage. All
gain transistors are operated in their linear region for the smoothest,
purest sound reproduction.

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There are two levels of bias --- high and low --- for maximum user
convenience. The low bias setting can be used when operating the unit
in standby or for non-critical listening. Indeed, since the low bias setting
still provides class A operation up to 200 watts, you should hear little
difference between the settings most of the time. For the absolute
highest quality reproduction of dynamic material and the most critical
listening, the amplifiers should be set to the high bias level for full class A
operation.
The power-on and bias select mode switches are a high quality rocker
switches hidden underneath the front center front face plate at the
bottom. You will feel two switches. The larger POWER ON switch is
located on the right of the smaller BIAS switch. The BIAS switch is next
to the left of the POWER On switch.
.
This photo shows the Amp On and the Bias Mode on LOW.

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Amp is off and bias setting is high.
Amp is off and the bias setting is low.

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Both Rocker switches are towards the faceplate, the amp is on and in
HIGH BIAS MODE.
When the Rocker switch on the left is pressed towards the rear, the amp
is in LOW BIAS MODE.
There are two red LED indicator lamps on the center front of the
faceplate. The lower lamp indicates POWER ON. The top LED indicates
BIAS MODE. The bottom lamp will glow at Full Intensity when the
POWER is ON. When the LOW BIAS mode switch is OFF, the top LED
LAMP indicator is the same intensity as the POWER ON lamp. When the
BIAS MODE switch is on, the TOP Lamp with glow half as intense
indicating that the amp is in LOW BAIS Mode. LOW BIAS Mode allows
the M-300 to run cooler and produce 200 watts. Many listeners keep the
amp on continually in this mode, only to switch to FULL Power when
critically listening. We suggest turning the amps off when not listening to
music for extended times, or leaving your home.

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Front LED Power and Bias Lamp Indicators
The Power On Lamp is located on the bottom with Bias Mode lamp
above.
For safety, we have built into the Clayton Audio design a power on lamp
on the rear panel. Please make certain that the glowing RED LAMP IS
OFF on the front face plate and OFF on the rear before connecting or
disconnecting any cables. See Photograph below.

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The rear panel with Power On Indicator Lamp.
The four long bumpers at each corner of the rear panel are NOT
FEET. DO NOT STAND THE AMP ON THESE BUMPERS. These are
Clayton Audio Safety Bumpers™and will prevent bending your
favorite cables and power cable when moving the amp too close to a
wall or solid object. As these amps produce heat, please make
certain they are not located next to drapery or furniture. If you
place the amps into a rack system they will need at a minimum of
24 inches of proximity clearance at the sides and top for proper heat
dissipation. The amps are best sounding when placed directly on
their own custom feet on a solid floor. There is no need to invest in
fancy cones or special pucks as feet. The Clayton Audio amplifier
feet are machined extra tall to allow air current to flow underneath
the chassis when placed on most carpets. High quality amp stands or
granite or marble slabs are optional.

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Clayton Audio Rear Bumpers
The power supply contains a 2KVA toroidal transformer with up to
200,000 microfarads of capacitance. The M-300 makes use of dual
separate power sources for the driver and output stages. The driver
stage incorporates a high-precision regulation circuit for stability. The
output stage is an extremely high current design using a filter to
enhance stability and minimize noise. No capacitors are used in the
signal path.
Both power supplies are symmetrically balanced in positive and negative
voltage to eliminate any possible instability caused by powering the
amplifier on and off. A precision power-on sequence control circuit is
also used to prevent any damage that might be caused by the initial
power surge.

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Please replace the Rear Fuse Protector after changing fuses or
selecting remote modes for safety.
The Fuse Panel and Remote Control and Remote Selector toggle
switch. Remove this panel prior to changing over to a triggered or
remote input. The toggle is in the Off, Local down position as the
default.

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Warranty
Clayton Audio warranties your M-300 monobloc amplifiers against any
defects in design or manufacture for three years from the date of
purchase. Defective units will be repaired within the warranty period
without charge for labor or parts assuming that the units have not been
altered or damaged through abuse, negligence, deliberate modification,
accident or improper operation. All repairs must be directly undertaken
by Clayton Audio. We ask that you ship the defective amplifier(s) to us,
after proper authorization. You are responsible for the one-way
shipping and insurance expenses and we will cover return shipping costs.
Equipment must be returned in the original boxes with the original
packing material along with a copy of the sales receipt from an
authorized dealer. This warranty is transferable from the original owner
to future purchasers with proof of resale and any subsequent owner will
receive the remainder of the three- year warranty from the date of the
original purchase.
You are responsible for mailing the enclosed warranty registration card.
This officially registers your unit and permits us to inform you of any
upgrades or improvements that we may offer. You may also receive new
production information from us. Your name and address will never be