The new Valfet,"Bootstrapped Transformer," Universal Power Amplifier, is a much changed sonically advantageous power amplifier that uses a completely new design much faster power source follower buffer to drive the loudspeaker.

The improvements are in the valve signal amplifier and the buffer, the buffer uses low voltage small signal, physically small, high gain transistors: in all the circuits driving the output transistors. The advantage here is the faster processing of audio signals.

This is achieved using bootstrapped power supplies to the new buffer design, via a dedicated separate power supply. The small 3 V/A transformer for this separate power supply is termed in this new design as the, "Bootstrap Transformer", The topology of this new design is published below.

Note. The high voltage, high current, power supply for the output transistors: top right in the diagram, is completely separated from the low voltage power supply below it. Further Note, the common connection for the +/- supply from the low voltage power supply is connected to the loudspeaker terminal. Therefore, all the processing and driving circuits float up and down: are bootstrapped, to the loudspeaker terminal.

The input is referenced to ground via a servo that is also bootstrapped to this loudspeaker terminal. The DC voltage offset on the loudspeaker terminal under no signal conditions is +/- 0.2 millivolts: this is exceptional.

The design is further improved by the use of a different much faster thermionic valve high voltage signal amplifier stage driving this new buffer design, and the whole new power amplifier comprising of valve signal amplifier and buffer is very fast: and has a flat frequency response from 5HZ to 100 KHZ.

There is a completely new conventional chassis design using fully shrouded EI transformers, the new design looks far different to the old closed cabinet design. The new chassis is being designed along with the new printed circuit boards.

Anticipated completion of the design to a new saleable product is early to late March 2008. This new product arrival should be on time. Watch this space ! The schematics and circuit description and evolutionary theory for this evolved far superior amplifier design are now included in the now new extended Valfet Audio Power Amplifier book.

There will be two new product that are the new design topology. One of the products is class A/B and class B selectable, the other product is class A and class A/B selectable.

Many people are critical of class A amplifiers because they are gas guzzlers, in most part this is an inaccurate assessment. However, there is greater listening to audio in the cold months when people do not go out so much and the radiator thermostats with central heating adjust automatically to conserve energy: if any new source of heat generation is introduced.

Many class A all valve amplifiers need their expensive output valves changed annually, this is very expensive. The new Valfet design that is a sonic match if not an improvement on all valve class A amplifiers uses only two cheap valves per monoblock amplifier, ( not inferior sounding ), so the maintenance costs are far less.

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