I possess a Fosgate T1500-1db amplifier, which experienced a failure resulting in one power FET and one output FET blowing.
I have since replaced both FETs along with the associated resistors. Currently, I am encountering a significant humming noise; however, when I connect a power ground to the input (RCA) ground, the humming ceases and the sound quality is restored to perfection. What areas should I investigate or which electronic component could be responsible for this issue?
Thanks
I have since replaced both FETs along with the associated resistors. Currently, I am encountering a significant humming noise; however, when I connect a power ground to the input (RCA) ground, the humming ceases and the sound quality is restored to perfection. What areas should I investigate or which electronic component could be responsible for this issue?
Thanks
Does the signal source have a grounded shield?
If so, do you read 0 ohms between the RCA shield and the ground for the signal source?
What is the signal source?
Is it powered by the same 12v supply as the amp?
If so, do you read 0 ohms between the RCA shield and the ground for the signal source?
What is the signal source?
Is it powered by the same 12v supply as the amp?
Q: Does the signal source have a grounded shield?
A: Yes
Q: Do you read 0 ohms between the RCA shield and the ground for the signal source?
A: Yes, I get 0 ohms.
Q: What is the signal source?
A: Car touch screen stereo.
Q: Is it powered by the same 12v supply as the amp?
A: No, Touch screen is powered by a 12v power supply by itself and the amp is powered by a bench power supply set at 13.8v.
A: Yes
Q: Do you read 0 ohms between the RCA shield and the ground for the signal source?
A: Yes, I get 0 ohms.
Q: What is the signal source?
A: Car touch screen stereo.
Q: Is it powered by the same 12v supply as the amp?
A: No, Touch screen is powered by a 12v power supply by itself and the amp is powered by a bench power supply set at 13.8v.
Q: What happens if you connect the grounds of the two power supplies together?
A: Nothing. This was done with the amp not connected. I took the ground from the bench power supply and touched it to the chassis of the touch screen.
A: Nothing. This was done with the amp not connected. I took the ground from the bench power supply and touched it to the chassis of the touch screen.
Q: What 'input' ground did you connect to with the power ground if the amp wasn't connected?
A: The amplifier was linked while I was playing music and noticed a humming sound. I connected the amplifier's power ground to the input ground on the amplifier that's coming from the stereo (touch screen). I disconnected the amplifier when I touched the stereo's power ground and the bench's power ground.
A: The amplifier was linked while I was playing music and noticed a humming sound. I connected the amplifier's power ground to the input ground on the amplifier that's coming from the stereo (touch screen). I disconnected the amplifier when I touched the stereo's power ground and the bench's power ground.
How are you hearing a hum without the amp connected?
Linked? Do you mean connected by RCA cables?
Linked? Do you mean connected by RCA cables?
Q: How are you hearing a hum without the amp connected?
A: The amplifier was connected to the power source and turned on, while the stereo was also powered on, playing music through RCA cables linked to the amplifier, which produced a loud humming noise. After conducting a brief investigation, I discovered that by connecting the power ground input of the amplifier to the ground of the RCA, the hum disappeared, resulting in excellent sound quality. In response to your request for a test, I disconnected the amplifier from the power supply and took the ground wire that was attached to the amplifier, briefly touching it to the stereo. Should I have kept the amplifier powered on during the test?
A: The amplifier was connected to the power source and turned on, while the stereo was also powered on, playing music through RCA cables linked to the amplifier, which produced a loud humming noise. After conducting a brief investigation, I discovered that by connecting the power ground input of the amplifier to the ground of the RCA, the hum disappeared, resulting in excellent sound quality. In response to your request for a test, I disconnected the amplifier from the power supply and took the ground wire that was attached to the amplifier, briefly touching it to the stereo. Should I have kept the amplifier powered on during the test?
For clarification with the source connected to the amp with RCAs, both on and playing audio.
There is hum, correct?
If you change nothing but connecting a wire between the two power supply grounds, is there a change in the hum level?
There is hum, correct?
If you change nothing but connecting a wire between the two power supply grounds, is there a change in the hum level?
Q:
For clarification with the source connected to the amp with RCAs, both on and playing audio.
There is hum, correct?
A: Yes
Q: If you change nothing but connecting a wire between the two power supply grounds, is there a change in the hum level?
A: If I connect the two power supply grounds together the hum is gone and plays normal.
For clarification with the source connected to the amp with RCAs, both on and playing audio.
There is hum, correct?
A: Yes
Q: If you change nothing but connecting a wire between the two power supply grounds, is there a change in the hum level?
A: If I connect the two power supply grounds together the hum is gone and plays normal.
After I tested the two power supply grounds, I realized that in a car, both the stereo and the amplifier share the same ground. Is Fosgate the only brand of amplifiers that produces a hum? I have connected many amplifiers using this same configuration, and none of them emitted a hum.
It shouldn't have a hum but if all is well in the car, I wouldn't worry about it.
Do both of your power supplies have 3-wire plugs?
Do both of your power supplies have 3-wire plugs?
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