McIntosh MC3500 Mark I Monoblock Power Amplifier – Vintage Valve Legend A rare opportunity to own a genuine McIntosh MC3500 Mark I single monoblock power amplifier, manufactured between 1968 and 1971. Famed for its effortless 350-watt output and legendary performance at the Woodstock Festival, the MC3500 remains one of the most desirable and powerful vintage tube amplifiers ever produced. This example is in used but fair cosmetic condition and was professionally serviced in January 2026, ensuring reliable operation while preserving its originality. Technical Specifications Power Output: 350 Watts RMS (Mono) Frequency Response: 20Hz – 20kHz (±0.5dB) Total Harmonic Distortion: 0.15% Input Sensitivity: 1.1V Signal-to-Noise Ratio: 95dB Output Impedance Taps: 1, 4, 8, 16, 50 & 64 Ohms Weight: Approx. 125 lbs (56.7kg) Tube Complement 8 × 6LQ6 output tubes 2 × 12AX7 2 × 6DJ8 1 × 6CG7 1 × 6BL7 Please see the detailed photographs provided as they form part of the description and therefore part of the sale. A video has been created to show she is tested and working . I will include a few spare new tubes as a startup gift. Shipping will be expensive due to weight so collection can be arranged. Shipping will be crated collection will be wrapped. Please be aware that this item is vintage and not garanteed, due to its Collectability the sale is final, and not return/refundable. A true collector's amplifier offering immense power, exceptional musicality, and iconic McIntosh engineering. Ideal for the discerning audiophile or vintage audio collector.