Inspired by the amplifier that inspired a generation.

There’s no denying the historic significance of the 1969 Woodstock Music and Art Fair. There had never been anything like it, and many would argue there’s not been anything like it since. With an unexpected crowd of over 400,000 people, there was a lot that could have gone wrong – and some things did. But one aspect that’s nearly universally agreed upon was how great all the musicians sounded. That sound quality is thanks in part to the McIntosh MC3500 Vacuum Tube Amplifiers that exclusively powered the sound system used at Woodstock.1 The MC3500 would go on to power many other influential music events.

It was at a 2019 event to celebrate the 50th Anniversary of Woodstock where McIntosh President Charlie Randall, realizing the historical importance of the MC3500, first dreamed of bringing it back into production. That proved no easy task considering it was first designed over 50 years ago. But after more than two years of development, that dream has become reality as McIntosh is proud to announce the MC3500 Vacuum Tube Amplifier Mk II.

BRAND: McIntosh

SERIES: MC3500 Mk II 1-Channel Vacuum Tube Amplifier
TYPE: Power Amplifier


  • The MC3500 Vacuum Tube Amplifier Mk II is a conservatively rated
    350 Watt monoblock that takes its inspiration from the original 1968-71
    MC3500, and incorporates everything we have learned about vacuum tube
    amplifier design since the 1960s.
  • Upgraded to modern standards and with modern components to deliver
    an audio performance worthy of its predecessor and the legacy of their
    shared model number.
  • Uses our Unity Coupled Circuit output transformer, which allows the full
    350 Watts to be safely delivered to virtually any speaker regardless if it has 2, 4 or 8-Ohm impedance.
  • Output powered by eight EL509S high-power output vacuum tubes,
    which was chosen specifically due to it having many similar qualities and
    characteristics of the 6LQ6 “sweep tubes” used on the original MC3500.
  • Like the original MC3500, the MC3500 Mk II has a fully balanced driver section that utilizes three 12AX7A and one 12AT7 vacuum tubes.
  • Power Guard Screen Grid Sensor™ (SGS) helps prevent premature vacuum tube failure by monitoring the screen grid current in the output tubes. If the current becomes too high, Power Guard SGS dynamically attenuates the
    input signal in real time to keep the vacuum tubes operating at safe levels.
  • Sentry Monitor™ observes the output current and shuts the amplifier off if it ever exceeds safe limits.
  • Uses a variation of our DualView™ Power Output Meter design, with the
    top scale showing the power output in both Watts and decibels, while the
    bottom scale shows the amplifier warmup time.
  • Front panel is machined aluminum with a bead blast finish and gold
    anodizing that emulates the look and finish of the original MC3500. A clear
    glass insert covers the meter; a black glass insert at the bottom houses the
    knobs and illuminated lettering.


A new MC3500 Mk II (left) with an original MC3500.


Power Output:
350 Watts into 2, 4 or 8 Ohms

Rated Power Band:
20Hz to 20kHz

Dynamic Headroom:

Damping Factor:

Frequency Response:
+0, -0.5dB from 20Hz to 20kHz
+0, -3dB from 10Hz to 70kHz

Total Harmonic Distortion:
0.3% maximum at any power
level from 250 milliwatts to
rated power, 20Hz to 20kHz

Signal to Noise Ratio:
120dB below rated output

Input Sensitivity:
3.8 Volts Balanced
1.9 Volts Unbalanced

Voltage Gain:
2 Ohms: 23db
4 Ohms: 26db
8 Ohms: 29db

Input Impedance:
22k Ohms

Overall Dimensions (W x H x D):
18” (45.7cm) x 11-13/16” (30cm)
x 22-5/8” (57.5cm)

121 lbs (54.9kg) net
147 lbs (66.7 kg) in shipping carton