Tandberg's advanced engineering offers less.

Tandberg's dedicated staff of audiophile engineers long ago decided that ideally there should be nothing between the listener and the music ... no IM, no THD, no TID ... no audible distortion of any kind.

However, in the real world of audio electronics, "nothing" wasn't easy to come by; virtually every aspect of the signal path, and the circuitry that supports it, required reevaluation.

Tandberg embarked on a 5-year research project to systematically localize and eliminate every source of audible distortion, however subtle.

In Pursuit of Nothing

The practical result of our concentrated research effort is the remarkable TPA 3006A Power Amplifier. Breaking new ground, and old rules, the TPA 3006A employs unique zero feedback MOSFET output stages. This is a difficult design topology, but the only one guaranteed to eliminate the audible time domain distortions undetected by conventional test methods. Available power output is 150 watts per channel into 8 ohms and 235 watts per channel into 4 ohms, with less than 0.02% THD/IM. And, although MOSFETs have been used before, our constant-source impedance driver stage design is specifically engineered, for the first time, to take full advantage of these remarkable output devices.

The voltage and current limiting protection circuits of conventional amplifier designs also proved to be major obstacles to full fidelity.

Tandberg's MOSFET configuration eliminates the need for all such circuit limitations; the MOSFET stages themselves are maintained at full linearity by a unique Voltage Comparator Circuit. The TPA 3006A, therefore, has an output-current capacity exceeding 25 amperes per channel, supported by a massive, tightly regulated toroidal transformer power supply with over 30,000 microfarads of filter/storage capacitance.

Damaging DC is kept from the output signal path via our (patented) Thermic Servo Loop system that monitors the amplifier's output, automatically and instantaneously rebiasing the amplifier as necessary ... but, unlike other designs, with no connection whatsoever to the musical signal.

Once the major areas of power amplifier distortion were eliminated, Tandberg engineers were free to pursue the much more subtle, less definable sources of sound degradation.

Further technical nuances Tandberg's pursuit of absolute fidelity led to the use of carefully chosen, costly high tolerance components: 1% metal-film resistors for their stability and low noise; plus sonically superior polypropylene capacitors (instead of electrolytic and ceramic types) are used in all audio stages. And, all audio stages employ discrete (no ICs!) circuitry for maximum headroom and minimum distortion.

Tandberg has even reevaluated circuit board design. The lowest possible noise levels and totally identical performance between channels could be realized only when there is symmetrical parts layout and the reverse side of the circuit boards copper-plated to form a shielding ground plane; all housed in an unusually compact, nonmagnetic, anodized extruded-aluminum chassis.

Compact & Cost Effective

Never before has a power amplifier of this degree of performance been compact enough to match our TCA 3002A Preamplifier and the world-famous TPT 3001A Programmable Tuner.

It should be evident that in the TPA 3006A, Tandberg has mounted an all out assault on audible distortion, breaking new ground in those areas that elude conventional measurements ... and designers.

The final proof, of course, is in the sound. Audition the TPA 3006A at your Tandberg dealer ... and hear why our engineers feel that they have achieved a quality of music reproduction comparable to the most costly esoteric units, in a compact, cost-effective design that is unobtrusive in any room setting.

For a Technical Paper on the remarkable TPA 3006A Power Amplifier and a beautiful color poster showing the complete Tandberg family of purist audio components, send $2 for postage and handling to: Tandberg of America, Dept. AM, One Labriola Court, PO Box 58, Armonk, N.Y. 10504.

(Source: Audio magazine, Sept. 1984)

Also see:

Tandberg Series 2000 receivers (April 1978)

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