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McIntosh MX121 Home Theater Processor - Dolby True HD, DTS-HD - Phono Input

Sale price$0.00
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Pickup currently unavailable at SkyFi 479

Mcintosh Mx121 Home Theater Processor - Dolby True Hd Dts-Hd Phono Input Preamplifier

McIntosh MX121 Home Theater Processor - Dolby True HD, DTS-HD - Phono Input

SkyFi 479

Pickup currently unavailable

479 South Broad Street
Glen Rock NJ 07452
United States


Complete MX-121 set from McIntosh with box, manual, remote, and the Audyssey DSX microphone/tripod to automatically setup the equalizer for your room and speakers.

No fiddling with individual bands, settings, etc., to get the best sound possible in your home theater.

In perfect condition and working same as the day it left the factory.

Some of the HDMI features and standards may be older, but best results are usually achieved from running your sources directly to your display from experience.

We have several multi-channel amplifiers available on our store, and of course you can pair this with higher-end stereo only amplifiers from McIntosh, Audio Research, Krell, etc to truly customize your home theater amplification per channels/front and rear soundstage.

McIntosh MX121 Sales Brochure

McIntosh MX121 Owner's Manual

Performance Features:
• HDMI 1.4a with 3D Passthru Switching
There are six HDMI 1.4a Inputs. HDMI Output 1 includes the new Digital Audio Return Channel (ARC) signal from the TV1, thus eliminating the need for an extra cable and simplifies operation. HDMI inputs are compatible with Deep Color, x.v.Color, Auto Lipsync and HDMI Component Control.

• Analog Video/Audio Switching with Scaling
Component Video Inputs and Composite Video Inputs (Analog Video Signals) are also converted to a Digital Video Signal with resolution up to 1080P at the HDMI Outputs.

• Balanced Inputs and Outputs
A pair of Balanced high level Inputs and an eight channel Balanced Output are provided, permitting long cable lengths without a loss in sound quality.

• Moving Magnet Phono Input
There is a Precision Phono Preamplifier for Moving Magnet Cartridges.

• Built-in Dolby True HD and DTS-HD Master Decoders
The MX121 also provides built-in decoding of the Dolby Pro Logic IIz, Dolby Pro Logic IIx, Dolby Digital EX, DTS Neo6 and DTS-ES Sound Tracks.

• Internet Streaming
The MX121 when connected to a network, offers Internet Radio, with music and photo streaming.

• Audyssey DSX®
Audyssey DSX is a scalable system that adds new speakers to improve surround impression. Audyssey DSX first adds Wide channels for the biggest impact on envelopment and then creates Height channels to reproduce the next most important acoustical and perceptual cues. Surround Envelopment Processing is used to enhance the blend between the front and surround channels.

Audio Specifications
Unless otherwise noted, the below MX121 Specifications where taken with Audyssey bypassed and manual Tone/EQ set to flat setting.

Frequency Response
±0.5dB from 20Hz-20,000Hz

Total Harmonic Distortion
0.005% maximum from 20Hz to 20,000Hz at rated output

Signal To Noise Ratio
Phono: 86dB below 10mV input (A Weighted)
High Level: 96dB below rated output (A Weighted)

Rated Output Voltage
2.5V Unbalanced Outputs (Main Zone)
5.0V Balanced Outputs (Main Zone)

Maximum Voltage Output
6V Unbalanced
12V Balanced

Output Impedance
220 ohms

Input Impedance
Phono: 47k Ohms, 65pf
High Level: 20k Ohms Unbalanced and Balanced

Sensitivity for Rated Output
Phono: 4.5mV
High Level: 450mV Unbalanced, 900mV Balanced

Maximum Input Signal
Phono: 50mV
High Level: 4.5V Unbalanced and Balanced

Tone Controls
Bass Control: ±6dB at 30Hz
Treble Control: ±6dB at 10,000Hz

Video Specifications
Signal System

Version 1.4 (includes support for Deep Color, x.v.Color, Auto Lipsync, Audio Return Channel and HDMI Component Control)

Analog Video Inputs scaled to a 1080P Digital Signal

Component Video Output Level
Y Output Level 1.0Vp-p (75 OHM)
PB/CB Output Level 0.7Vp-p (75 OHM)
PR/CR Output Level 0.7Vp-p (75 OHM)

Composite Video Output Level
1Vp-p (75 OHM)

Overall Dimensions
Width is 17-1/2 inches (44.45cm)
Height is 7-5/8 inches (19.37cm) including feet
Depth is 19-1/2 inches (49.53cm) including the Front Panel, Knobs, Rear Panel Connections and USB Drive

30 pounds (13.6Kg) net, 54 pounds (24.5Kg) in shipping carton

The SkyFi Testing Process for Preamplifiers (All):

We start with a visual inspection of all internal components to make sure there are no signs of stress or aging. Capacitors are checked for telltale sings of bulging or leaking, resistors are checked for signs of overheating or cracking, and transistors are checked for signs of stress or damage. Special attention is paid to the power supply which is the most common source of failure for preamps. We then power up the unit and run a simple 1k sine wave while monitoring the low voltage output on an oscilloscope for signs of distortion or noise to get a baseline.

At this point we will lubricate and clean all switches and potentiometers (that are not sealed) with a high quality contact cleaner, and then re-test all functions for any signs of noise or scratching.

Final testing involves putting actual music through the preamplifier We have learned over time that some issues are only noticeable to a trained ear while listening to a familiar source material. Our test bench has reference vintage KEF speakers that we are super familiar with which will quickly reveal any discrepancies. Some preamps will then move into the listening room where they will be tested with our in-house reference system.

Please click here for detailed specifics regarding our specialized packing process that separates us from the rest.




Yes from an MX123 which fits this MX121 exactly


Yes and Online




Yes - Power

Physical Condition


Working Condition


SKU: 101090