When I set the voltage output level I’m getting a different reading at the ac receptacle. Using my voltage meter the voltage is off by 3 volts. To get an output reading at the receptacle of 120vt the setting
Is at 117vt. Is this normal? doesn’t sound like it should be.
I agree with your concern. However, a few questions first… Are you certain your voltage meter is accurate? Is it a Digital meter or an older Analog (with swinging needle)? Does it have fresh batteries? The “first rule” of testing to is ensure equipment is calibrated and in good shape.
You’re so right. I used to be in the business of measuring mass flow and density. Our density meters could detect differences to 0.0001gm/cc. I once got a call from a metrology lab complaining that our meter disagreed with the device they were using as reference. Turned out to be a car battery hygrometer!
Previous comments could certainly be valid. The volt meter that you’re using might not be 100% accurate. We do calibrate the P20’s oscilloscope, but if you’re certain the volt meter is accurate, you can re-calibrate the P20. Shoot me an email at jamesh@psaudio.com and I can walk you through this.