McIntosh MC3500 Monoblocks (98 sets ever made)

R650,000.00 R300,000.00

Of the numerous tube audio amplifiers produced by McIntosh over many years, the mighty McIntosh MC3500, or its industrial version the McIntosh MI-350, designed by Mile Nestorovic in about 1968, is unsurpassable – in my humble opinion, the greatest commercial tube amp ever made.

This amp is derived from the 1949 original McIntosh unity coupled design shown above and was produced by McIntosh between 1968 and 1971.

The MC-3500 and MI-350 offer beauty in style and finish, functionality, reliability and performance.

A blend of art and science.

The MC-3500 and MI-350 amplifiers were produced by McIntosh between 1968 and 1971.

This was the golden age of tube audio – at the pinnacle of its commercial development. However the world changed very quickly soon after with the introduction of solid state amplifiers. Their low cost, comparable reliability and lower weight soon displaced high powered tube amps. The result was that although the McIntosh patent was granted in 1971 its commercial purpose was limited by evolution in a competing technology.

The combination of patent protection and solid state power transistor developments meant commercial interest in this technology lapsed.

Nonetheless, the MI-350 and MC-3500 stand for all time as monuments to the technological possibilities and listener rewards of high-fidelity vacuum tube audio.

Tragically, due to competitive forces and technological development, a comparative solid state professional quality amplifier having identical specifications to the MC3500/MI350 can be purchased in 2012 for as low as one quarter of the 1971 price of the Macs. Allowing for inflation over 40 years that is a tremendous cost reduction over time.

When the current 2012 resale value of around USD$40,000.00 – as determined by the market – is considered, then the ratio of used MC 3500/MI350 to brand new solid state amp is something like 100 times. The audiophile market obviously thinks this expenditure is justified.

However notwithstanding published specifications, there is no comparison of sound quality. Solid state amplifiers just do not cut it for audiophile performance and the cost of the MC3500/MI350 is entirely justified by its performance. There is simply nothing like it on this planet.

If you do not believe that claim then prove it for yourself.


McIntosh MC 3500 (Stereo & Mono Writeup)

The McIntosh MC 3500 sets a new precedent in high power performance and flexibility.
Many years of diligent research, space age product advances and careful examinations  of new developments in component parts have lead to the McIntosh MC 3500, a new Laboratory Standard.
The quality performance that is demanded in the scientific laboratory  is your for the highest performance in a home music system.
McIntosh  developed the first low distortion, high quality, high powered amplifier in 1947. the secret then was the Unity Coupled circuit and Bifilar Output Transformer.
The MC 3500 has made another new advance. Again transformer design has made the difference. A new output transformer with 5 primary windings, interleaved with the secondary to give you maximum output, lowest distortion, multiple output impedance for any type type of sound distribution requirement. The new McIntosh Pentafilar output transformer and Unity Coupled circuit means lowest distortion, flat power response, long, trouble free cooler operation at high power.
McIntosh has produced the answer to the majority of sound problems. With the McIntosh MC 3500, your music system will produce music as never before. All the instruments will be reproduced with clarity and accuracy. No more will you hear just a barrage of sound. Now you will hear each instrument clearly and cleanly without the cloudiness produced by the lack of power in the amplifier. The McIntosh MC 3500 is the ultimate in high power amplifiers.



350W RMS continuous. 500W RMS Maximum.

Frequency Response: 20-20kHz (+0 -0.5dB).

Total Harmonic Distortion:  0.15%.
Intermodulation Distortion: Unmeasureable – ie behold measuring instrument threshold

Hum and Noise Levels: -95dB.

Output – Rated Load Impedances: 1, 4, 8, 16, 50 and 64 ohms.
Note: Rated Power Output for 1 ohm load is 300W and 4 Ohm load is 320W
Output Load Circuits: Can be isolated from ground – ie “balanced output”.

Internal impedance: less than 5% of Rated Load Impedance.
Input impedance: 200k.
Input sensitivity 1.1V RMS

Anodized gold and black panel. (Note: Some after-market replacement panels were supplied in natural aluminium anodised finish).
Input connectors: RCA and BNC (front and rear).
Gain control.
Meter Range switch: off, volts, dB, dB-10 or V1-V8.
Power circuit breaker: on or off.
Output range switch: 1 , 4,  8, 16, 50, and 64 ohms with corresponding voltages 17.3, 35.8, 53.0, 75.0, 132 and 150V.
Dual banana output connectors.
Meter: Monitors output voltage, dB or cathode current for each output tube.
Heavy duty drawer-pull style handles.
Line voltage switch: 117 or 125V.
Output barrier strip.
Input terminals.
Sub sonic filter switch: In or out.
Cooling fan.

8-6LQ6/6JE6B output,
Solid state full-wave bridge rectifier.

DIMENSIONS: 19″ Wide rack mounting x 10 1/2″ High x 17″ Deep behind front panel.

WEIGHT: 125 lbs

400W at zero signal
900W at maximum signal

Sold from 1968-1971.
1971 retail price USD$1099.00