McIntosh MA6900

Commentary

Integrated amplifier with 5-band equalizer.

The 5-band equalizer circuit can enhance or reduce five frequency bands to 12 dB.
When the knob is in the center position, it is completely removed from the signal circuit and the sound of the input source can be confirmed as it is.

It is equipped with a phono equalizer amplifier suitable for MM type cartridges.

All input, output and data ports are equipped with logic operated electromagnetic magnet switches, and signal switching is realized by digital logic IC.
In the relay used in this process, contacts plated with gold, rhodium and ruthenium are enclosed in glass tubes filled with inert and oxygen-free gas to increase reliability.

Equipped with a motor drive volume control compatible with a remote control, the resistor is laser trimmed to achieve highly accurate tracking.

Equipped with an output auto-former, the amplifier and speaker are always in an ideal matching state, and a long life is realized without losing sound quality.

It is equipped with various protection circuits as a risk management measures to protect the amplifier itself and to prevent damage to the speakers in the event of an abnormal situation.
Power Guard consists of a waveform comparator that monitors the waveform of the amplifier input and output signal. Normally, it does not output anything. However, when the amplifier is driven to output beyond its maximum power capability and a difference occurs between the input and output waveforms, the comparator controls the amplifier gain to suppress distortion of the output.
Equipped with a sentry monitor, it senses the dynamic operating time, voltage and current of the output stage and controls the current within non-destructive limits.
Other built-in features include a DC hoar to ground the DC, temperature protection that does not degrade SN by natural air cooling, turn-on delay that delays the operation of the amplifier by approximately two seconds when the power is turned on, and in-rush protection that eliminates stress on the power transformer when the power is turned on.

It is equipped with a gold plated input / output jack.

Stainless steel chassis is used for the chassis.

Serial data output port is installed.

Equipped with a large blue eyes output display meter with lighting.

Wireless remote control is included.

Model Rating

Type	Integrated amplifier
Rated Output (Both Channels Operating)	200W + 200W (2 ω, 4 ω, 8 ω, sine wave continuous output)
Load impedance	2 Ω, 4 Ω, 8 Ω (Independent Terminal)
Output frequency bandwidth	20 Hz to 20 kHz
Total harmonic distortion factor	0.005% or Less (20 Hz to 20 kHz, 250 mW to 150W, Both Channel Operation)
Intermodulation distortion factor (when both channels are operated)	Up to 0.005% (250 mW to 200W at any combination of 20 Hz to 20 kHz) * When the instantaneous peak output does not exceed the rated output of 400W
Frequency characteristic	20 Hz ~ 20 kHz + 0 -0.5 dB
Maximum output voltage of preamplifier section	8 v (20 Hz ~ 20 kHz)
Input sensitivity	Phono : 2.5 mv (2.5 v rated output, 0.5 mv IHF) High Level : 250 mv (2.5 v rated output, 50 mv IHF) Power amp in : 2.5 V (rated output)
Signal-to-noise ratio (IHF-A network)	Phono : 90 dB (84 dB IHF at input of 10 mV or less) High Level : 100 dB (90 dB IHF below rated output) Power amp : 110 dB (below rated output)
IHF dynamic headroom	2.4 dB (2 Ω, 4 Ω, 8 Ω)
Damping factor	100 or More (8 Ω)
Maximum input signal	Phono:90mV High Level:8V
Voltage gain	High Level → tape : 0 dB High Level → main : 20 dB
Equalizer control	50 Hz, 150 Hz, 500 Hz, 1.5 kHz, 10 kHz ± 12 dB
Pwer	100 VAC, 50Hz/60Hz, 4.0A
External dimensions	Width 444.5x Height 181.0x Depth 419.1 mm
Weight	33.8kg