McIntosh C39 Solid State Preamp w/Phono, Complete Set

Free Shipping on *ALL* Electronics (Excluding Speakers, Contiguous 48 US States Only)

Great full function preamp best used for a two channel setup. McIntosh called this an "Audio/Video Control Center" when it was first released as a sign of the times.

Offers no less than 12 sets of inputs for even the most complicated stereo setups, including a phono input to connect your favorite turntable.

In very good condition with slight signs of use. The front glass faceplate is super clean and intact.

To get it in tip-top shape we changed blown bulbs and cleaned all the controls, resulting in super quiet and smooth operation.

Fully tested and sounding wonderful. 

This listing is for a fill kit including the preamp, manual, remote and double McIntosh shipping carton for safe travels. 

We also have a matching vintage McIntosh wood cabinet available at the time of this writing. Please contact us if you'd like to add one to your order.

Recommended Cables:

Kimber Kable - RCA Interconnects - Better

Kimber Kable - RCA Interconnects - Best

Kimber Kable - Phono Interconnects - Better

Kimber Kable - Flagship Tonearm Interconnects - Best

Owner's Manual:

Click here for a PDF copy of the original Sales Brochure

Click here for a PDF copy of the original Owner's Manual

Specs:

FREQUENCY RESPONSE

+0, -05dB from 20Hz to 20,000Hz

RATED OUTPUT

25V at Main and Switched 1 and 2 Outputs

OUTPUT IMPEDANCE

Main, 600 ohms

MAXIMUM VOLTAGE OUTPUT

8V at Main and Switched 1 and 2 Outputs, from 20Hz to 20,000Hz

TOTAL HARMONIC DISTORTION

0.002% from 20Hz to 20,OOOHz at rated output

SENSITIVITY

Phono: 2.5mV for 2.5V rated output, (O.5VIHF)

High Level: 250mV for 2.5V rated output, (50mV IHF)

SIGNAL TO NOISE RATIO 

Phono: 90dB below 10mV input, (84dB IHF)

High Level: 105dB below rated output, (95dB IHF)

MAXIMUM INPUT SIGNAL 

Phono: 90mV

High Level: 10V

INPUT IMPEDANCE

Phono: 47K ohms and 65pF capacitance

High Level: 22K ohms

VOLTAGE GAIN

Phono to Tape: 40dB 

Phono to Main: 60dB 

High Level to Tape: OdB 

High Level to Main: 20dB

TONE CONTROLS

Bass and Treble variable, 12dB boost to 12dB cut

AC POWER OUTLETS

One switched for area A power amplifier, one switched for area B amplifier and one unswitched

POWER REQUIREMENTS

120 volts, 50/60Hz, 25 watts

MECHANICAL INFORMATION

Front panel measures 17-1/2 inches (445cm) wide, by 7-1/8 inches (18.1cm) high. Depth behind mounting panel including clearance for connectors is 15 1/2 inches (39.4cm). Knob clearance required in front of the mounting panel is 1-3/8 inches (35cm)

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 PCB’s 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.