One of the big problems with amplifiers built in this price/performance category is oddly, performance (no-one seems to have a problem with charging the price...). At this elevated price level, tube amplifiers, especially, suffer either very low power, or such poor bandwidth (due to their transformer-coupled designs) that credulity is strained to even call them high fidelity. Whilst transistor amplifiers, regardless of price, still retain the solid-state artifact that continues to identify them as transistor amplifiers to even the casual listener.

Fortunately, the type of OTL technology that Atma-sphere pioneered back in the late 70s and early 80s is well suited for high power application - it seems the bigger they make them, the better they can make them sound. Atma-sphere have now proven it’s possible to build a truly high power amplifier that is all-tube and has wide bandwidth at the same time. No transformer amplifier can produce 200, yet alone 400 watts and get it right at any audio frequency; such a transistor amp is unknown to man. But an OTL can do it easily, without solid-state artifact, resulting in a high power amplifier that is actually musical.

The MA-3 has all of the same features as the ‘smaller’ models, plus a few not seen in any amplifier produced before. It is still class A, all triode, and fully differential, with the patented direct-coupled output circuit (OTL). There is still only a single gain stage in the amp, so the signal path remains very direct, a feature essentially unknown in amps of this class. Construction remains point to point with custom wire.

The new features are intended to make the amp very easy to own and operate:

Switchable feedback and dual speaker posts are also added for more flexible operation.
Other features are listed to the right.

• Introduction to Atma-sphere
• Atma-sphere’s 20 year rule
• Why we use the 6AS7G Power Triode
• Debunking Common Power Amplifier Myths
• Understanding Basic Circuits
• Using Single-Ended Equipment with Atma-Sphere Preamplifiers