It is relatively easy to determine whether a transformer is defective or not, by using a multimeter. B + denotes the high voltage of the amplifier. IMPORTANT: Disconnect power and let all the capacitors discharge before you begin. Remove the output tubes from the amplifier. There are dangerous … Continue reading →
There are several ways to make the correct bias for a valve. We have fixed bias, where the grid is supplied with a constant negative voltage, and automatic, or cathode bias where we bias the valve by giving the cathode … Continue reading →
Today Russian tubes are frequently used by enthusiasts all over the world, but it is not always easy to find out what Russian tube that can be used as a replacement for a Western tube. Information from the sellers of … Continue reading →
This is a simplified approach, just to explain how it works. A loudspeaker usually has an impedance of 4 – 8 ohms, and an output tube will usually demand a load of several k.ohms. To make this work we need … Continue reading →
Grid current are in most cases unwanted, but can in certain circuits be necessary to make the circuit function as wanted, that will be covered in a separate article later. Now I will look at the causes for unwanted grid … Continue reading →