McIntosh MP1100 Tube Phono Preamplifier - JUST DISCONTINUED, LAST ONE

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General:
The best phono preamp ever made from McIntosh or just about any other maker.  

Sadly it was discontinued this year and they are becoming scarce.  

The MP1100 is a pleasure to use because of the front-mounted adjustment controls and large VU meters. Behind the glass panel at top you can see the (4) 12AX7 vacuum tubes, a very nice touch.  It's also capable of digitizing records for archiving purposes with a plethora of digital outputs.   

It accommodates multiple turntables at once thanks to a total of three sets of RCA phono inputs. It also features a pair of balanced XLR inputs and outputs which is the absolute best way to connect a turnable If your tonearm allows it.  

This preamp was tested in our lab and is functioning beautifully.

This is complete kit including packing, manual and accessories, like when it left the factory.  

SkyFi Cosmetic Notes:
Some very light scratches on the chassis, looks minty overall.

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:
Single Owner

Connections:
RCA inputs and Outputs, XLR Inputs and Outputs, IEC power port

General Sound:
Smooth, uncolored, undistorted natural and clean

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:
Everything like when it arrived new

Packing:
Original Manufacturers Packing

Reviews:
Click Here

Specs:
Frequency Response
±0.2dB from 20Hz to 20,000Hz
+0.2, -3dB from 10Hz to 50,000Hz

Total Harmonic Distortion
0.005% maximum from 20Hz to 20,000Hz (Line In)
0.02% maximum from 20Hz to 20,000Hz (Phono In)

Rated Output
4V Balanced
2V Unbalanced

Maximum Voltage Output
20V RMS Balanced
10V RMS Unbalanced

Sensitivity (for rated output)
Phono MM - 10mV
Phono MC - 1.25mV
Line In - 2V Unbalanced
Line In - 4V Balanced

Signal To Noise Ratio (A-Weighted)
Phono MM - 84dB below 5mV input
Phono MC - 80dB below 0.5mV input
Line In - 118dB below rated output

Input Impedance
Phono MM and MC - 25, 50, 100, 200, 400, 1k or 47K ohms and 50 to 400pf in 50pF steps
Line In - 50k Unbalanced, 100k Balanced

Maximum Input Signal
Phono MM - 100mV
Phono MC - 10mV
Line In - 10V Unbalanced
Line In - 20V Balanced

Voltage Gain
Phono MM and MC - Selectable 40dB, 46dB, 52dB, 58dB or 64dB
Line In - 0dB

Output Impedance
100 ohms Unbalanced
200 ohms Balanced

Phono Equalization
RIAA, LP, NAB, AES or 78

Noise Filters
Rumble: -3dB at 50Hz, Slope 24dB per Octave
Scratch: -3dB at 6,000Hz, Slope 12dB per Octave

Digital Outputs
Coaxial, Optical, USB

Digital Output Sample Rates
PCM - 24Bit 96kHz or 192kHz

Power Control (Trigger)
Maximum Input and Output Signal 12VDC, 25mA

Tube Complement
Four 12AX7A, two per channel

Power Requirements
Field AC Voltage conversion of the MP1100 is not possible. The MP1100 is factory configured for the following AC Voltage:
120 Volts, 50/60Hz at 50 watts
Standby Power, less than 0.5 watts

Dimensions:
17-1/2” (44.5cm) x 6” (15.2m) x 18” (45.7cm)

Weight:
26 lbs.

Approximate Age:
2021

Link to Manual:
Click Here

Recommended Cables:
Kimber Kable - RCA Interconnects - Better

Kimber Kable - RCA Interconnects - Best

Kimber Kable - Phono Interconnects

Kimber Kable - BALANCED XLR Connectors - Better

Kimber Kable - BALANCED XLR Connectors - Best

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.

When we first power on a preamplifier we connect its RCA output to a Sencore PA81 Power Analyzer which simulates real world loading conditions and gives us an oscilloscope interface.

The first order of business is checking that the volume control works smoothly throughout its entire range with acceptable channel balance. This is accomplished by feeding a 1 KHz sine wave into one of the preamp’s line level inputs while monitoring the preamp’s output on an oscilloscope.

We then switch to a 1 KHz square wave to test the tone controls, loudness function, and filters where applicable. During this step we are watching for equal alteration of the test signal by both channels. This also helps us identify dirty controls that will need treatment.

Once the basic line stage functions are verified, we test each input individually. This is especially important for devices that use relays to select their sources. If the preamp is equipped with a phono stage we test that as well. We use an inverse RIAA filter which allows us to feed a reference test signal into the phono input with the proper RIAA equalization and level. A square wave or sine sweep is used to verify that the device’s phono stage is faithfully reproducing the RIAA curve. If the preamp under test has balanced inputs and/or outputs these are tested as well.

We finish up our bench testing with a listening test with our bench amplifier and reference speakers. During this test we check for hum or hiss that may not have shown up in earlier testing. We also check that all of the tone controls and filters perform as expected.

If the preamplifier has remote control functions these are also tested. Preamps with tube circuits or complicated power supply topologies are connected at our long term test rig for extended stress testing under real world conditions.