J
Joe Waddell
- Jan 1, 1970
- 0
All,
I have a Leslie Combo Preamp pedal that I use to connect musical
instruments to a Leslie 147 Speaker.
The pedal has a Pilot Light in it that indicates if the Leslie 147
Speaker is rotating at "Fast" speed.
A foot switch on the pedal closed and opened the circuit that
controlled speed. When the circuit was open, the Leslie spun "Fast"
and when the circuit was closed, the Leslie spun "Slow".
There are two wires running to the foot switch. Right before that
switch, the Pilot Light is located, connected to both wires that are
running to the foot switch.
When the footswitch is closed, the current flows through the footswitch
and not the pilot light, and the pilot light is not lit.
When the foot switch is open, the current flows to the pilot light and
causes it to emit light.
Here's the strange thing that I need help with. I noticed that in Fast
mode (with the pilot light lit from the open footswitch), an annoying
noise would come out of the Leslie Speaker. I, just by chance,
discovered that the Pilot Light was the source of this noise.
Some sources on-line talk about needing to ground pilot lights in
electronics, or it can cause a 120Hz buzz.
Has anyone every heard of this before? Could someone explain to me
what a Pilot Light is? Is it like a lightbulb, in that it acts as a
resistor in a circuit?
Thanks,
Joe
I have a Leslie Combo Preamp pedal that I use to connect musical
instruments to a Leslie 147 Speaker.
The pedal has a Pilot Light in it that indicates if the Leslie 147
Speaker is rotating at "Fast" speed.
A foot switch on the pedal closed and opened the circuit that
controlled speed. When the circuit was open, the Leslie spun "Fast"
and when the circuit was closed, the Leslie spun "Slow".
There are two wires running to the foot switch. Right before that
switch, the Pilot Light is located, connected to both wires that are
running to the foot switch.
When the footswitch is closed, the current flows through the footswitch
and not the pilot light, and the pilot light is not lit.
When the foot switch is open, the current flows to the pilot light and
causes it to emit light.
Here's the strange thing that I need help with. I noticed that in Fast
mode (with the pilot light lit from the open footswitch), an annoying
noise would come out of the Leslie Speaker. I, just by chance,
discovered that the Pilot Light was the source of this noise.
Some sources on-line talk about needing to ground pilot lights in
electronics, or it can cause a 120Hz buzz.
Has anyone every heard of this before? Could someone explain to me
what a Pilot Light is? Is it like a lightbulb, in that it acts as a
resistor in a circuit?
Thanks,
Joe