Mcintosh - MC3500 mk1 Ζεύγος κλασικών, 350 βατ ανά κανάλι! Διπλός μονοφωνικός ενισχυτής tube - Πολλαπλά μοντέλα

MC3500 Mark I. Μονομπλόκ ενισχυτές ισχύος με σωλήνες/βαλβίδες.

Plus
Custom step-down transformer
Extra box full of new old stock tubes/valves

McIntosh MC3500 Mark I Monoblock Valve Power Amplifiers
Matched Pair – Extremely Rare – Largely Original – USA
Description
Offered for sale is an exceptionally rare matched set of McIntosh MC3500 Mark I monoblock valve power amplifiers, widely regarded as among the most important high-power valve amplifiers ever produced.

Manufactured in Binghamton, New York during the mid-1960s, the MC3500 Mark I occupies a unique position in audio history. Developed during the golden age of American valve engineering, it was designed as a no-compromise amplifier capable of delivering unprecedented power, stability, and musical authority from vacuum-tube topology. Its reputation was further cemented through professional and live sound use, where absolute reliability at extreme output levels was essential.
With approximately 100 units manufactured, the MC3500 Mark I is one of the rarest production amplifiers ever offered by McIntosh Laboratory and is seldom encountered as a matched pair.
This set remains in largely original condition, having received only minimal and sympathetic servicing to ensure correct operation while preserving historical integrity. The amplifiers present as authentic survivors, retaining their original character rather than being over-restored.

Condition & Service History
Serviced in December 2025
All capacitors tested and confirmed within original factory specifications
One unit fitted with a new VU meter
On the second unit, two capacitors and one transistor replaced
No unnecessary modifications or circuit alterations

Tubes & Setup
Currently fitted with brand-new, fully matched Sylvania power tubes
Gains professionally set and balanced
20 spare power tubes included (mix of NOS and used)
Included Accessories & Spares
Custom-built step-down transformer (110V USA to 220V EU), allowing safe operation in European markets
Spare McIntosh transformer (condition unknown)
New spare gain potentiometer

Cosmetic Condition (Important)
These amplifiers are approximately 60 years old and show honest signs of age and use consistent with their history:
One amplifier has a small but deep scratch on the aluminum faceplate, located to the right-hand side of the VU meter
The other amplifier shows light corrosion on the rear plate, limited to the edge area only; it does not penetrate or affect the interior
Additional marks and wear to the frames
Please review the detailed photographs carefully, as they form an integral part of the description and therefore part of the sale.

Functionality Proof
Pre-amplifier and CD player not included
These were used solely to produce a functionality video recorded 2026
Video can be provided to the buyer on request as proof of operation and the sale is considered final, no returns accepted.

Technical Specifications (McIntosh MC3500 Mark I)
Type: Monoblock vacuum tube power amplifier
Output Power: 350 watts continuous at 8 ohms
Output Tubes: 6 × 6LQ6 per monoblock
Input Tubes: Multiple small-signal valves (original McIntosh configuration)
Frequency Response: Approx. 20 Hz – 20 kHz
Total Harmonic Distortion: < 0.5% at rated output
Output Impedance Taps: 4Ω, 8Ω, 16Ω
Input Sensitivity: Approx. 2.5 V
Voltage: 110V AC (USA specification)
Operation in EU: Via included step-down transformer
Weight: Approx. 54 kg per monoblock
Manufacture: McIntosh Laboratory Inc., Binghamton, NY, USA

Shipping and fees.
I am prepared to build 3 custom plywood crates.
2 x monoblocks plus crates 120kg
1 x sdt , parts and spares. 55 kg
Total 175 kg. Approx
Within the EU up to around 1200 euro approx. But quotes can be prepared .

You are welcome to collect the items from me directly yourself Or arrange transport with pallets and i will assist. Or liase with me telephonically to arrange shipping at your costs.
Our custom shipping crates are perfect to ensure their safety door to door.

These are incredible amplifiers. They can handle anything from electrostatic speakers to delicate paper coded tannoys.