What is Tube Biasing ?
Tube amps are a very old technology and are difficult beasts to handle – especially if you don’t know what you are doing. Inside the power amp is typically voltages ranging from just 12 volts to 440 Volts+ in DC – which will easily kill you – especially if you get electrocuted with both hands. You will see the ‘old’ Television guys working with one hand in their pocket – it’s not because they enjoy themselves – it’s to stay alive! So – inside the power amp is a thing called a tube – or in the UK a valve. Actually there’s probably at least two, four, six or eight tubes. Each ‘pair’ of tubes works (in the simplest way of describing) like a route to the next pair – or in a push-pull mode of operation. But these tubes need to have a particular voltage set to the most efficient to drive the tube correctly – this is known as the Bias voltage. Often there is a small adjuster to change the bias voltage – not enough bias voltage and the tube runs cold and does not distort well, too much bias vo
