McIntosh C11 Vintage All Tube Preamplifier - Full Restoration


This McIntosh C11 received a full electrical restoration from our friends and experts over at Audio Classics.

This electrical restoration included a rebuild of the power supply with custom multi-section filter capacitor cans, replacement of every out of spec coupling capacitors, and the installation of brand new gold plated RCA connectors to address some intermittent grounding issues.

Condition is very good considering its age considering it was only made from 1961-1963! You can tell it was very well cared for over the years as there are no signs of rust or corrosion.

It is physically complete with the exception of the rear cover plate for the tubes.

Tube Notes:
This preamp includes an assortment of used vintage Telefunken ribbed plate 12AX7's. Two of the existing tubes were found not to spec in our testing, so we replaced them with ribbed plate Telefunken tubes from our in-house collection.

The tube placement was optimized for best performance on line and phono inputs.

Functional Notes:
These vintage units tend to have slight imbalances in their volume controls. A small compensation of the Right Channel output trimmer brought this unit into the proper range, giving great center image balancing throughout the listening range of the volume control.

Please see our last photo or the owner's manual below for specifications:

McIntosh C11 Vintage All Tube Stereo Preamplifier 

Click below to add our recommended matching cables from Kimber Kable, all brand new as SkyFi is an official Kimber dealer.

Kimber Kable - RCA Interconnects

Kimber Kable - Phono Interconnects

The SkyFi Testing Process for Preamplifiers:
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.



Original Box



Online Only


Not Applicable


Yes - Power Only

Physical Condition


Working Condition


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