TRI Rectifier and SAG
- Almost all 'RAT' Amps use the 'TRI Rectifier' System -
A Switch on the Rear Panel of the Amp Allows the Selection of 3 Different Rectifiers.
A. - Silicon - Standard 'Silicon' Diodes.
B. - V1 - 'Valve Rectifier' - Running at Half Power.
C. - V2 - 'Valve Rectifier' - Running at Full Power.
All Amplifiers use a Rectifier to convert the Raw AC Voltage from the Mains Transformer into DC Voltage. The Amp Circuits Need DC Voltage to work. If, for example, you Hit a Power Chord on your Guitar, the Amplifier Circuitry Suddenly Demands a Large Dose of Power from the Mains Transformer. Silicon Diodes are Extremely Efficient and can convert the Raw AC into DC almost instantaneously, to Feed the Amplifiers Needs. Valve Rectifiers are a Different Story. Generally Speaking, they can't Cope with Sudden High Demands of Energy and they 'Starve' the Amp of Power until they can catch up with the Demand - This is Called 'SAG' - and it Sounds GREAT!
The typical sound Produced by an Amp using 'Silicon' Diodes would be -
- Attack - Sustain - Release - Decay -
Using the 'V1 Valve' Rectifier, the Sound would be Closer to -
- Attack - Swell - Extended Sustain - Release - Decay -
To your Ears -
In 'Silicon Mode' the Initial Note Attack is Sharp and Crisp - Like a Modern Amp.
In 'V1 -or- V2 Valve Mode' the Initial Attack is Almost Soft and Laid Back with Longer Sustain - Like a Vintage Amp.
It is OK to Switch Between Rectifiers While the Amp is Running.
This System works equally well with 'Class A' - 'Class A/B' - 'Single Ended' - 'Push Pull' - 'Cathode Bias' and 'Fixed Bias' Amp Designs.