PA 3100 HV Ampilier
The PA 3100 HV is based on the outstanding PA 3000 HV integrated amplier, and most of its sub-assemblies are identical. The immediately obvious difference is in the front panel, which houses a pair of VU meters displaying the actual output per channel on a logarithmic scale, shown as Watt into 4 Ohm. A further development is the redesigned analogue mains section and power supply, which is similar to that of the A 3000 HV. This makes it possible to connect the supplementary PS 3000 HV Power Supply in order to gain a further increase in stability, quality and performance of the power supply system as a whole. We also succeeded in improving sound quality by revising the pre-amplifer sections.

Like all HV devices the PA 3100 HV is of consistently symmetrical, channel-separate construction, and is divided into compartments. The pre-amplifer circuit boards, containing the input section, volume control and high-voltage amplifer, are located in the upper compartment below the case lid; their symmetrical construction eliminates electro-magnetic inuences. This compartment consists of thick-walled aluminium plates, and is completely separated and shielded from the lower compartment, which houses the power output stages, the current and voltage power supply and the loudspeaker outputs.

The dividing wall between the upper and lower sections is 10 mm thick, and - as you would expect - is also made of aluminium. This means that the voltage amplifer (upper compartment) and current amplifer are mounted on separate circuit boards housed in separate sections of the case, in order to prevent any possibility of either section affecting the other. The sophistication of the layout goes even further, for the two sections are also galvanically separated.
The net result of this uncompromising design effort is a complete lack of feedback effects between the loudspeaker currents and the voltage amplifer stages, and absolute freedom from loudspeaker load effects. It is possible to obtain a further improvement in the stability and power of the PA 3100 HV by connecting the PS 3000 HV to it using the special Powerlink cable with M-23 connectors incorporating high-current contacts. In this confguration the internal mains section of the PA 3100 HV is responsible for the power supply to the input stages and the high-voltage amplifers, while the external PS 3000 HV provides power to the output stages, ensuring delivery of the substantial currents demanded by the power output stages. In terms of sound quality, the great advantage of this overall design is that the PA 3100 HV is isolated from the load currents and mains-induced interference, for these can have adverse effects on sound quality.