McIntosh MC451 Owner's Manual

2

Introduction (continued)

The MC451 has 150 watts of vacuum tube power

to drive your loudspeaker’s mid ranges and tweeters.

With the MC451, the tubes will not be challenged

or overloaded by low-end reproduction because the

solid state section has 300 watts dedicated to driving

the woofers.

Fine tuning your system is made simple with the

built-in crossover. This allows you to match the

crossover point to your loudspeakers and maximize

the power available to each section. Alternatively,



section and bypass the crossover. This is perfect if

you have crossovers external to the MC451.



®

for clipping protection, Sentry Monitor™ for

over current protection, and ThermalTrak

1

output

transistors for stable bias and temperature control.

The output Autoformer™ provides the full 300W

of power regardless of loudspeaker impedance and

provides DC protection to the outputs.





®

for output tube protection and Sentry

Monitor™ for over current protection. The Unity

Coupled Output Transformer™ provides the full

150W of power regardless of loudspeaker imped

-

ance and provides DC protection to the outputs.

Table of Contents

Safety First �� 2

Introduction�� 2

Where to Put It� �� 3

Dimensions �� 3

Removal of Foam Insert Over Vacuum Tubes �� 4

Connector Information �� 5

Connecting a Loudspeaker � �� 5

Front Panel Displays and Knobs �� 6-7

Rear Panel Connections and Switches �� 8-9

Connection Diagram �� 10-11

Setting Up the Crossover� �� 12-13

Solid State Specifications �� 14

Vacuum Tube Specifications �� 14

General Specifications� �� 14

Packing Instructions �� 15

Packaging Parts List �� 15

Thank You from All of Us at McIntosh

You have invested in a precision instrument that

will provide you with many years of enjoyment.



with the features and instructions to get the maxi-

mum performance from your MC451.

If you need further technical assistance, please

contact your dealer who may be more familiar with

your particular setup including other brands. You

can also contact McIntosh with additional questions

or in the unlikely event of needing service.

McIntosh Laboratory, Inc�

2 Chambers Street

Binghamton, New York 13903

Technical Assistance (607) 723-3512

Fax (607) 724-0549

Customer Service (607) 723-3515

Fax (607) 723-1917

Email support@mcintoshlabs.com

Website www.mcintoshlabs.com

Please Take A Moment

For future reference, you can write down your

serial number and purchase information here. We

can identify your purchase from this information

if the occasion should arise:

Serial Number: __________________________

Purchase Date: ___________________________

Dealer Name: ___________________________

Introduction



is an all-in-one solution for bi-amping

loudspeakers. Utilizing our Hybrid

Drive™ technology, it captures

the harmonic beauty of vacuum tubes for a

loudspeaker’s mid and high ranges while still having

an

abundance of power dedicated to the low end. The



its optimized combination of a vacuum tube and a



Safety First



separate document called Important Additional

Operation Information Guide.

1

ThermalTrak

™

is a trademark of Semiconductor

Components Industries, LLC

McIntosh MC451 Dual Mono Power Amplifier

Owner's Manual - Page 2