The McIntosh MC275 Mk5 is a 75-watt-per-channel stereo vacuum tube power amplifier that can also operate in a 150-watt mono parallel configuration. It features a polished stainless steel chassis, balanced and unbalanced inputs.
MK5:
Power Output: 75W per channel into 4, 8, or 16 ohms (stereo); 150W into 2, 4, or 8 ohms (mono)
Frequency Response: 20Hz to 20,000Hz (+0 / -0.5dB)
Total Harmonic Distortion: 0.5% maximum at any power level from 250 milliwatts to rated power
Signal-to-Noise Ratio: 100dB to 105dB
Damping Factor: Greater than 14 to 22
Tube Complement: 4x KT88 output tubes, plus a mix of small signal tubes like 12AX7A and 12AT7
Dimensions (W x H x D): 16.5" x 8.25" x 12" (42 cm x 21 cm x 30.5 cm)
Weight: 67 lbs (30.5 kg) net
MK4:
The McIntosh MC275 MK IV is a two-channel vacuum tube power amplifier produced from 2004 to 2006. It features a polished stainless steel chassis, a dedicated power on/off switch, a rear-mounted detachable power cord socket, and delivers 75 watts per channel into 4, 8, or 16 ohms.
Power output: 75 watts per channel in stereo mode (4, 8, or 16 ohms) or 150 watts total in mono bridged/parallel mode.
Tube complement: Four KT88/6550 output tubes, three 12AX7A tubes, and four 12AT7/12AZ7 small signal drivers.
Frequency response: +0, -0.5dB from 20Hz to 20,000Hz (+0, -3.0dB from 10Hz to 100,000Hz).
Total Harmonic Distortion (THD): 0.5% maximum from 250 milliwatts to rated power.
Signal-to-Noise Ratio: -100dB to -105dB below rated output.
Dimensions: 12" wide x 7.5" to 8.25" high x 16" to 16.5" deep.
