I’ve been struggling with this for a while.
Had to replace a couple of resistors on the boards, so figured since I was going to tear the amp down, I should try another grounding protocol to see if I could solve what’s been an ongoing issue.
As the amp sits on its own, with no source, it is dead quiet. After readjusting the voltages on the boards, I am getting 1mV of AC on the output. Very happy about that 🙂
However, as soon as I hook up a preamp, I get a buzzing sound.
The photo attached showed how it currently is wired up.
Made use of a star ground. The secondary centres are connected to the star. The star is connected to one end of each of the power supply boards. The ground terminals on the amp boards are also connected to the star. The earth ground is connected to the star, and the chassis. I just tried connecting the RCA ground to the star also. Both the grounds of the RCA terminals are connected together and a single wire connects them to the star
What on earth (pun intended) am I not getting here?
Thank you for your thoughts.
P
Had to replace a couple of resistors on the boards, so figured since I was going to tear the amp down, I should try another grounding protocol to see if I could solve what’s been an ongoing issue.
As the amp sits on its own, with no source, it is dead quiet. After readjusting the voltages on the boards, I am getting 1mV of AC on the output. Very happy about that 🙂
However, as soon as I hook up a preamp, I get a buzzing sound.
The photo attached showed how it currently is wired up.
Made use of a star ground. The secondary centres are connected to the star. The star is connected to one end of each of the power supply boards. The ground terminals on the amp boards are also connected to the star. The earth ground is connected to the star, and the chassis. I just tried connecting the RCA ground to the star also. Both the grounds of the RCA terminals are connected together and a single wire connects them to the star
What on earth (pun intended) am I not getting here?
Thank you for your thoughts.
P
Attachments
Update.
I pulled the ground wires from the amp boards, and it’s now silent.
Power supply boards are grounded on input end to star..
Secondary center is connected to star.
Star is connected to house ground, and house ground is also directly connected to the chassis at IEC.
RCA inputs are grounded at amp boards.
Finally.
It’s done 🙂
I pulled the ground wires from the amp boards, and it’s now silent.
Power supply boards are grounded on input end to star..
Secondary center is connected to star.
Star is connected to house ground, and house ground is also directly connected to the chassis at IEC.
RCA inputs are grounded at amp boards.
Finally.
It’s done 🙂