McIntosh MC2102

Commentary

This stereo power amplifier was announced as a new generation vacuum tube amplifier.

The MC2102 uses a total of eight vacuum tubes for each channel : two high-gain, low-distortion twin triodes 12AX7x2, two high-voltage twin triodes 12AT7x2, and four beam power tubes KT88/6550x4.
One 12AX7 is used for balance input and the other for voltage amplification and phase inversion. The signal is sent to the grid of one 12AT7 push-pull voltage amplifier. The 12AT7 push-pull bootstrap voltage amplification is used, and the second 12AT7 operates as four KT88/6550 push-pull cathode followers. The output tube is connected in parallel push-pull.
The amplifier operates in three modes : stereo, mono-parallel, and mono-bridged.

The power amplifier section uses a Macintosh unique Unity Couple Circuit with two features.
In a normal amplifier, the output power is taken from the plate and cathode of the output tube, while the output power is taken from only the plate, and this circuit is a unity couple circuit.
The output transformer is equipped with two primary windings of bifilar winding, one for the cathode and the other for the plate.
This circuit configuration realizes flat frequency characteristics and wide-band power handling.

Multi-filer wound TRANSFORMERS is used.
The four output tubes send signals to the output transformer through two primary windings for the plate and cathode, which are bifilar windings wound simultaneously together, and the secondary winding consists of five windings distributed between the primary windings, which are connected in parallel to provide a very low series resistance for the speaker load.
This method not only compensates for excellent speaker damping, but also provides tight coupling between the primary and secondary windings, resulting in flat frequency characteristics and wide power bandwidth.
The addition, the steel sheets used for the transformer are stacked with silicon steel sheets for audio applications with the highest quality crystal, enabling full power output even at 17 Hz.

The input slide switch allows you to select between balanced and unbalanced.
Balanced operation improves noise removal capability, and the in-phase component rejection in the mid-range is more than 60 dB.

It is equipped with the traditional blue eyes power meter that can turn off the light of the meter.
This meter allows you to select either the Watts position, which indicates changes in the volume of the program source, or the hold position, which stops at that position and returns slowly to the rest position when maximum power is indicated.

A funnel-shaped pipe is installed around the base of the output tube to enhance the cooling effect by increasing the convection effect of air.

The vacuum tube socket uses gold-plated contacts and ceramic material with high insulation resistance and excellent high-temperature resistance.
The unbalanced and balanced input connectors and the huge binding post that clears the large 200A output are also gold-plated.
You can use spade connectors, banana plugs and wires up to AWG No. 8 for this binding post.

The main chassis is made of mirror-finished stainless steel.

Model Rating

Type	Stereo power amplifier
Stereo output	100W + 100W (2 ω, 4 ω, 8 ω, sine wave continuous minimum average power output) Output RMS voltage : 14.2 V (2 Ω), 20.0 V (4 Ω), 28.3 V (8 Ω)
Mono-parallel output	200W (1 ohm, 2 ohm, 4 ohm, sine wave continuous minimum average power output) Output RMS voltage : 14.2 V (1 Ω), 20.0 V (2 Ω), 28.3 V (4 Ω)
Monobridge output	200W (4 ω, 8 ω, 16 ω, sine wave continuous minimum average power output) Output RMS voltage : 28.3 V (4 Ω), 40.0 V (8 Ω), 56.6 V (16 Ω)
Total harmonic distortion factor	0.5% or Less (at all levels from 250 mW to rated output)
Intermodulation Distortion (SMPTE)	0.5% or less (when the instantaneous peak output does not exceed twice the rated power output)
Rated output frequency	20 Hz to 20 kHz
Frequency characteristic	20 Hz ~ 20 kHz + 0 -0.25 dB 10 Hz ~ 100 kHz + 0 -3.0 dB
Signal-to-noise ratio (A-weighted)	100 dB (Rated Output or Less)
Broadband damping factor	18 or more
Output load impedance	Stereo : 2 Ω, 4 Ω, 8 Ω Monoparallel : 1 Ω, 2 Ω, 4 Ω Monobridge : 4 Ω, 8 Ω, 16 Ω
Input impedance	Unbalanced : 20k Ω Balance : 40k Ω
Input sensitivity	1.0V
Vacuum tube used	12AX7x4 (input and phase inverted) 12AT7x4 (voltage amplifier and driver) KT88 or 6550x8 (Output Tube)
Pwer	100 VAC, 50Hz/60Hz, 5.8A
Power consumption	390W
External dimensions	Width 455.4x Height 257.2x Depth 406.4 mm Width 445x Height 257x Depth 432 mm (listed in separate catalog)
Weight	40kg