hi all--
i posted this over at headwize, but i thought i'd see if anyone here could offer some insight as well
I recently built an op-amp based amp (a buffered cmoy, more or less), and when i turn the pot full open I am getting some serious RF interference...the unit acts like a theremin, and the nature of the noise changes when i reorient or touch the case.
I built the amp on a PCB I laid out and had professionally made, and then i put it in a 1455 series hammond. The circuit is totally isolated from the case. I am powering the unit from 2 9v's, but i used a rail splitter in case I ever just wanted to use a single 9v.
I was advised to tie the audio ground to the case at the input, and bypass the supply at the opamp's power pin with a .1uf cap. These both seem like good ideas to me...do folks here agree? Any other ideas (e.g., from a layout standpoint)?
thanks!
i posted this over at headwize, but i thought i'd see if anyone here could offer some insight as well
I recently built an op-amp based amp (a buffered cmoy, more or less), and when i turn the pot full open I am getting some serious RF interference...the unit acts like a theremin, and the nature of the noise changes when i reorient or touch the case.
I built the amp on a PCB I laid out and had professionally made, and then i put it in a 1455 series hammond. The circuit is totally isolated from the case. I am powering the unit from 2 9v's, but i used a rail splitter in case I ever just wanted to use a single 9v.
I was advised to tie the audio ground to the case at the input, and bypass the supply at the opamp's power pin with a .1uf cap. These both seem like good ideas to me...do folks here agree? Any other ideas (e.g., from a layout standpoint)?
thanks!
