McIntosh MC252 Amplifier - 250W, 3D Faceplate, Fiber Optic Lighting

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General:
One of the most compact high power amps made by McIntosh, and one of the best looking in our opinion featuring 3D glass and heavy aluminum end caps.  

This amp is super capable and full of features. It would cost you over $9k to buy a new equivalent McIntosh amplifier today

This model also features fiber optic lighting on the meters. This gives the meters a super nice even glow, compared to previous generations.

At our test bench both channels tested to 250W with extra headroom. This would be a solid choice for power hungry speakers.

This particular example is in excellent condition and will come with its original manual, brand new double McIntosh box and power cord. 

From McIntosh:
• Power Output
The MC252 consists of two separate power amplifier channels, each capable of 250 watts into 2, 4 or 8 ohm speakers with less than 0.005% distortion. The two channels can be combined into a single channel with 500 watts into 1, 2, 4, 8 or 16 ohm speakers with less than 0.005% distortion.

• Patented Autoformers
The McIntosh designed and manufactured Output Autoformers provide an ideal match between the amplifier output stage and speaker loads of 2, 4 and 8 ohms. The Autoformers also provide perfect DC protection for your valuable Loudspeakers.

• Patented Power Guard
The patented McIntosh Power Guard Circuit prevents the amplifier from being over driven into clipping, with its harsh distorted sound that can also damage your valuable Loudspeakers.

• Patented Sentry Monitor with Thermal Protection
McIntosh Sentry Monitor power output stage protection circuits ensure the MC252 will have a long and trouble free operating life. Built-in Thermal Protection Circuits guard against overheating.

SkyFi Cosmetic Notes:
A couple of very light scratches, Overall very good condition.

Brand Background:
McIntosh Laboratory is an American manufacturer of handcrafted high-end audio equipment based in Binghamton, New York. The company was founded in 1949 by Frank McIntosh. The company designs and produces audio amplifiers, stereo tuners and other consumer electronics products.

Ownership:
Second Owner

Connections:
RCA, XLR, 5 way speaker binding posts, IEC power

General Sound:
Big beautiful musical sound with little fatigue.

Cosmetic Condition:
8/10 = Very Good. Excellent front faceplate, one minor flaw on chassis side or top. See our detailed rating description here.

Working Condition:
Working perfectly and tested in our lab and listening room.

Included:
Unit, Box, Manual

Packing:
Original Manufacturers Packing

Specs:
Power Output Stereo
Minimum sine wave continuous average power output per channel, all channels operating is:
250 watts into 2 ohm load
250 watts into 4 ohm load
250 watts into 8 ohm load

Power Output Mono Bridged
Minimum sine wave continuous average power output is: 500 watts into 4 ohm load
500 watts into 8 ohm load
500 watts into 16 ohm load

Power Output Mono Bi-Amp (Parallel)
Minimum sine wave continuous average power output is: 500 watts into 1 ohm load
500 watts into 2 ohm load
500 watts into 4 ohm load

Output Load Impedance
2, 4 or 8 ohms (Stereo Mode)
1, 2, 4, 8 or 16 ohms (Mono Modes)

Rated Power Band
20Hz to 20,000Hz

Total Harmonic Distortion
Maximum Total Harmonic Distortion at any power level from 250 milliwatts to rated power output is 0.005%

Intermodulation Distortion
Maximum Intermodulation Distortion if instanta- neous peak output per channel does not exceed twice the rated output, for any combination of fre- quencies from 20Hz to 20,000Hz, with all channels operating is 0.005%

Dynamic Headroom
2.0 dB

Frequency Response
+0, -0.25 dB from 20Hz to 20,000Hz
+0, -3 dB from 10Hz to 100,000Hz

Sensitivity
1.6 Volts Unbalanced Input
3.2 Volts Balanced Input

A-Weighted Signal To Noise Ratio
112 dB below rated output

Input Impedance
10,000 ohms Unbalanced Inputs
20,000 ohms Balanced Inputs

Wide Band Damping Factor
Greater than 40

Dimensions:
Width is 17-1/2 inches (44.45cm)
Height is 9-7/16 inches (23.97cm) including feet
Depth is 14-13/16 inches (37.62cm) including the Front Panel and Knob

Weight:
95 lbs.

Approximate Age:
2003

Link to Manual:
Click Here

Recommended Cables:
Kimber Kable - RCA Interconnects - Better

Kimber Kable - RCA Interconnects - Best

Kimber Kable - BALANCED XLR Connectors - Better

Kimber Kable - BALANCED XLR Connectors - Best

Kimber Kable - Speaker Cables - Better

Kimber Kable - Power Cords - Better

Kimber Kable - Power Cords - Best

Testing Process:
We start with a visual inspection of all internal components to make sure that there are no signs of heat stress or damage. Capacitors are checked for telltale signs of predictive failure including bulging, shrunken wrappers, or physical leakage. We also inspect the PCBs for discoloration from resistors or transistors that may have been running hot. On vintage units we often spot check select capacitors for value and ESR.

If the amplifier passes visual inspection, we move on to a controlled power on sequence using a Sencore safety analyzer to monitor current draw in real time. Once the amplifier is determined to be safe to operate, we connect it to full AC mains for function and power testing. We connect the speaker outputs of the amplifier to a Sencore PA81 Power Analyzer which acts as a dummy load, DC offset monitor, and oscilloscope interface. We start with a low level 1 KHz test signal at the amplifier's input and slowly increase its amplitude while monitoring the output on an oscilloscope for signs of noise, clipping, distortion, or improper channel balance. We continue increasing the signal level until the amplifier reaches clipping.

At this point we take an output power measurement and compare it to the spec sheet of the amplifier to verify proper performance. If the device under test has both balanced and single ended inputs they are both tested at this time.

We finish off the bench evaluation with a 1 KHz square wave check and a 20 Hz to 20 KHz sine sweep to assess the amplifier's frequency response characteristics.

This battery of tests will usually reveal if the amplifier has any issues that need further attention.

Before the device leaves the bench, we perform a listening test with actual music using a variety of preferred test tracks. Our benches are outfitted with familiar monitor speakers which help us identify inconsistencies that will not always show up on our test gear. The main things that we are listening for are hum or noise with no signal present, proper center image, clicks, pops, or any other obvious undesirable audio characteristics.

If the unit passes all of these tests it is moved to our long term testing rig where we simulate real word operating conditions for 6-8 hours minimum. This allows us to monitor the unit for signs of thermal runaway or intermittent issues that only crop up when the unit has fully come up to temperature.