McIntosh MC3500 MKII (2021–)
The McIntosh MC3500 MKII is a 350-watt monoblock vacuum tube amplifier announced November 4, 2021, with shipping beginning December 2021. It is a reissue and modern reworking of the original MC-3500, the amplifier McIntosh built from 1968 to 1971 and the model that powered the sound system at Woodstock ’69. McIntosh president Charlie Randall has said the buzz around the 50th anniversary of Woodstock in 2019 inspired the redesign. The company spent more than two years developing it.
The MKII looks like a direct descendant of the 1968 original. The front panel is machined aluminum with a bead-blast finish and gold anodizing that emulates the original, and the black rubber bumpers are replicated from the vintage amps. The U-shaped siderails echo the old broadcast-style chassis. McIntosh is explicit, though, that the MKII is aimed at the hi-fi audiophile market rather than the professional/broadcast market the MKI served. One deliberate change: the EL509S output tubes have no top plate connection caps, which makes tube replacement safer than on the original.
Under the hood, the MKII uses eight EL509S output tubes - chosen for their similarity to the 6LQ6 “sweep tubes” used in the original - plus a fully balanced driver section with three 12AX7A and one 12AT7. The first 12AX7A is the differential input amp, the second is the buffer/driver for the voltage amp, and the third is the voltage amp. The output stage is built around McIntosh’s Unity Coupled Circuit output transformer. The amp is conservatively rated at 350W rms into 2, 4, or 8 ohms, with a guaranteed +2.4dB of dynamic headroom. The front-panel meter is a variation of the DualView design. The top scale reads power in watts and decibels, and the bottom scale shows amplifier warmup time. The meter is gradated 0 to 100 percent.
Period coverage has been mostly descriptive. What Hi-Fi? called it “both a thoroughly modern and thoroughly retro amplifier,” and noted it as a component reserved for the highest of hi-fi systems. That fits the $15,000 MSRP (one dealer, Audio Classics, lists it at $17,500, and some overseas pricing runs far higher). Fidelity magazine said it delivers an audio performance worthy of its predecessor. No independent measured review with opinionated commentary has surfaced in the archive.
Two units are required for stereo, and up to five can be used in a surround system with subwoofer. The amp accepts balanced and unbalanced inputs and uses McIntosh’s patented gold-plated Solid Cinch speaker binding posts. Shipping weight is 150 lbs. The schematic is explicitly not available, and no dimensions, damping factor, or input sensitivity figures are documented. The MC3500 MKII is not the “world’s best tube amplifier.” That claim belongs to the original MC-3500, per oestex.com.
Known Specs
- Type: Monoblock vacuum tube amplifier
- Power output: 350W rms into 2, 4, or 8 ohms; +2.4dB dynamic headroom
- Tubes: 8× EL509S output; 3× 12AX7A + 1× 12AT7 driver
- Maximum harmonic distortion: 0.3% (250mW to rated power, 20Hz–20kHz)
- Frequency response: +0 / −0.5dB, 20Hz–20kHz; +0 / −3.0dB, 10Hz–70kHz
- Signal-to-noise ratio: 120dB
- Inputs: Balanced and unbalanced
- MSRP: $15,000 USD
- Shipping weight: 150 lbs
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