McIntosh C22 Vintage Tube Preamplifier, Restored, Highly Collectable
This is the Holy Grail of preamps from McIntosh.
An All-tube unit providing that warm and engaging vintage sound that so many are after.
Restored by Audio Classics in 2006 and kept in storage since!
Here are some details about the restoration work performed to this C22 based on our review of the work itself, along with the Audio Classics receipts.
• Full power supply rebuild
• All mutli-section electrolytic capacitors replaced
• Selenium rectifiers swapped to silicon with proper compensating resistors
• Full update of main preamp board
• Both axial electrolytic capacitors replaced
• All paper caps replaced with Audio Classics axial Polypropylene, Sprague, and Panasonic caps.
• All jacks replaced with new custom panels and gold plated RCA's
• Controls cleaned
• Volume control replaced or reconditioned
• Power Cord Replaced
SkyFi Tube Notes: All tubes are Amperex 12AX7 Orange Globe. All were tested on our Amplitrex AT1000 tester. They all test strong with great triode balance. A very nice set of tubes.
Perfectly matching vintage McIntosh wood cabinet available for an additional $499 including shipping, just select the option in this listing to include.
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 - Better
Kimber Kable - RCA Interconnects - Best
Kimber Kable - Phono Interconnects - Better
Kimber Kable - Flagship Tonearm Interconnects - Best
±0.5 db from 20 cps to 20,000 cps.
Less than 0.2% at 10 volts output, 20 to 20,000 cycles. Less than .02% at 3 volts output, 20 to 20,000 cycles.
HUM AND NOISE
High Level Inputs: 85 db below rated output
Low Level Inputs: Less than 1.5 microvolts at input terminals.
INPUT SENSITIVITY AND IMPEDANCE
Auxiliary, Tape, Tuner 1, and Tuner 2: 0.25 volts, 250,000 ohms. Phono 1 and Phono 2: 2 millivolts, 47,000 ohms. Microphone: 2.5 millivolts, 1 megohm.
Tape Head: 2 millivolts, 1 megohm.
Tape Compare: 0.25 volts, 250,000 ohms.
Main (2 jacks on each channel) : 2.5 V with rated output. Tape: 0.25 V with rated output. Left Plus Right: 1 V from generator impedance of 25,000 ohms.
Auxiliary, Tape, Tuner I, and Tuner 2: To Main Output, 20 db (10 to 1).
To Tape Output, 0 db (1 to 1). Phono 1 and Phono 2 (At 1 KC): To Main Output, 62 db (1250 to 1). To Tape Output, 42 db (125 to 1). Microphone: To Main Output, 60 db (1000 to 1). To Tape Output, 40 db (100 to 1). Tape Head (At 500 cps): To Main Output, 62 db (1250 to 1). To Tape Output, 42 db (125 to 1).
AUXILIARY AC OUTLETS (5)
1 unswitched for turntable or tape machine (Red), 4 switched (Black).
117 volts 50/60 cps AC, 34 watts.
6 each 12AX7.
TAPE JACK SWITCH
2 position, connects panel jacks to allow signals to be fed from or to the C22 to record or playback using an external portable tape recorder.
Separate channel 11 position switch type,± 20db at 20 cycles.
Separate channel 11 position switch type,±20 db at 20,000 cycles.
COMPENSATOR SWITCH RIAA or LP record equalization.
TAPE SWITCH Normal, or Tape Monitor.
RUMBLE FILTER 50 cps cutoff.
HF FILTER 5000 cycle cutoff.
ADDITIONAL SET·UP CONTROLS
The following controls are located behind the front panel on the top of the C22 chassis. These controls are readily accessible by depressing the PANLOC buttons to slide the C22 forward from the mounting panel.
OUTPUT LEVEL CONTROLS (L, L+ R, AND R)
Allows the balance of the enti re system to be conveniently adjusted.
LOW FREQUENCY TRIM CONTROLS (L AND R)
Allows frequencies below 100 cps to be boosted up to 6 db
TAPE EQUALIZATION CONTROLS (L AND R) Adjusts tape head input high frequency response.
2 position, normal (0°) or reverse (180°).
PILOT LAMP INTENSITY SWITCH 2 position, bright or dim.
Front panel; 16 inches wide by 57/16inches high; chassis (including PANLOC shelf) 15 inches wide by 5 inches high by 13 inches deep, including connectors; clearance in front of mounting panel including knobs,lYz inches.
16 pounds net, 25 pounds in shipping carton.
McIntosh C22 Tube Preamplifier - Owner's Manual
The SkyFi Testing Process for Preamplifiers:
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 1KHz 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 1KHz 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.
Yes - Power Only
Physical Condition (Info Here)
7 / 10
10 / 10