It regulates the voltage from the power supply to the individual components with in the pre-amp.
6 responses Add your response
Regulators are good for several reasons. If the supply voltage to a stage sags in use then then the stage is drawing more current than the supply can continously supply, and this may be audible. A well designed regulator will also by definition keep noise from the power supply out of the amplifier circuits.
The regulator in effect acts like a giant capacitor to maintain the voltage and reduce noise.
Think of it like the "cruise control" on your car.
You set your cruise control to 45 MPH, and your car is
starting to climb a hill. It will naturally tend to slow
down going up hill. The cruise control will open the
throttle to produce more engine power for the heavier
load of climbing the hill. That way you don't slow down
going up the hill.
When your music demands more power to drive the amplifiers
in your preamp - the regualator makes sure the heavier
load doesn't drag down the voltage. It, in essence, lets
more power into the system to handle the heavier load.
That's about as good an analogy as I can think of at the
Dr. Gregory Greenman
Le doc's analogy is good. Now think of this increasing and decreasing (of speed or voltage) in the very short term by turning the road and hill into music with a very stong pulse. At every beat of the thumpdrum (or bass guitar, or...), with an unregulated system, the voltage sags downward and then back upward. That pulsing puts ('modulates') that ryhthm on the amp's voltage supply, which puts some unpredictable portion of that pulsing signal on every other portion of the amplifier, thereby making the entire system sound not as good. In the best systems, EVERY voltage-gain stage in EVERY channel has its own regulator thereby making not only that gain stage sound better but also making EVERY gain stage sound better.
Poweramps often have regulators on their voltage-gain and driver stages but not on the output stage. The output stage is only infrequently regulated because regulating such a high-current supply is expensive. Regulating voltage-gain stages is relatively inexpensive.