MONO Amplifier

The Mono amps consist of a gain amplifier in a fully symmetrical design with all transistors in class A and an output stage in a "diamond" configuration that is not included in the feeback loop.

Both inverting and non inverting inputs are addressable via XLR or RCA
connectors.

During power on, a relay separates the output stage from the gain amp. There are no relays or resistances in the loudspeaker output, each output transistor is protected by a fast fuse in the collector line.

In the "diamond" circuit, the four Sanken output transistors are driven from current sources. The driver transistors reduce the drive current to the needed amount just as the signal demands. In such a design the driver transistors work in class A modus, only the output transistors are in class AB.

The output current amp is much faster than the gain amp (about 2MHz compared to 400 kHz of the gain stage), by this all signals of the gain amp are fed to the loudspeaker without additional phase delay. As there is no overall feedback, the damping factor of the output is phase stable as well.

All stages of the Monos are DC coupled, a DC-servo regulator stabilises the output to 0VDC. A DC protection circuit switches the amp off, if DC is detected at the output of the voltage amp.

The power supply consist of four large power condensers each 33000mFd and a 500 Watts transformer capable of 1500 Watts for short time (10 min). The very compact design shows the shortest possible internal wiring. An inrush current limiter reduces the switch on current.

The power transistors are connected thermically to large heathsinks on both sides of the amp and additionally are cooled down by an 8mm strong bottom plate that couples completely to a granite slab which is delivered with the amp.