All AC powered audio gear uses rectifiers. They change AC from your wall socket into the DC required to run electronics.
The "rectifier" is built from diodes. The diodes may be either solid state or tube (btw Mullard is a tube brand).
There are different types of rectifier circuits. Most are what are called "full wave" and utilize both the positive and negative going parts of the AC waveform to generate pulsating DC at twice the line frequency. This is easier to filter.
Almost all modern gear uses solid state rectification. It generates little heat and most of all has relatively low voltage drop.
Tube rectification is bulky, requires a larger power transformer (filament voltage) and most of all has relatively high voltage drop.
What this means is that tube rectifiers will tend to gently compress the music. As the current demands of the amp increase with volume, the voltage output of the tube rectifier tends to sag a bit, thus producing compression.
BTW, this effect is very noticable in tube guitar amps (my other avocation), and can affect playing style. Some guitar amps even allow the player to switch between solid state and tube rectifiers to exploit this effect.
I think that tube rectifiers are a potential source of dynamic coloration in hifi gear.
The "rectifier" is built from diodes. The diodes may be either solid state or tube (btw Mullard is a tube brand).
There are different types of rectifier circuits. Most are what are called "full wave" and utilize both the positive and negative going parts of the AC waveform to generate pulsating DC at twice the line frequency. This is easier to filter.
Almost all modern gear uses solid state rectification. It generates little heat and most of all has relatively low voltage drop.
Tube rectification is bulky, requires a larger power transformer (filament voltage) and most of all has relatively high voltage drop.
What this means is that tube rectifiers will tend to gently compress the music. As the current demands of the amp increase with volume, the voltage output of the tube rectifier tends to sag a bit, thus producing compression.
BTW, this effect is very noticable in tube guitar amps (my other avocation), and can affect playing style. Some guitar amps even allow the player to switch between solid state and tube rectifiers to exploit this effect.
I think that tube rectifiers are a potential source of dynamic coloration in hifi gear.