PPP - Voltage Accuracy

[hkval]

When I totally turn off the PPP or disconnect it from its power source for several minutes or longer, the THD and Voltage reading can be all over the place when I turn it back on. I found that if I then take out all plugs and connect the PPP to its power source I can adjust the voltage to 120 and the THD comes back to 0.4 from approx. 3.5.
The adjustment screw underneath can be turned beyond 1 full rotation so be careful that has not happened in a previous adjustment. I made that mistake ONCE and my output THD was even higher than the input.If so, just keep turning it until it holds at 120. My input is usually 124 and THD 3.5 and my output is always 120v and .4THD.

[Still-One]

Originally Posted by hkval

When I totally turn off the PPP or disconnect it from its power source for several minutes or longer, the THD and Voltage reading can be all over the place when I turn it back on. I found that if I then take out all plugs and connect the PPP to its power source I can adjust the voltage to 120 and the THD comes back to 0.4 from approx. 3.5.
The adjustment screw underneath can be turned beyond 1 full rotation so be careful that has not happened in a previous adjustment. I made that mistake ONCE and my output THD was even higher than the input.If so, just keep turning it until it holds at 120. My input is usually 124 and THD 3.5 and my output is always 120v and .4THD.

Looking at the repair manual that Dan sent me awhile back, I read it that the adjustment for input voltage is separate from the adjustment from THD. Am I reading this incorrectly?

1. With the unit in standby, press the Mode Down, Mode Up and Power Button (Logo) simultaneously.
2. The 3-digit display should light up. The logo and buttons should not be backlit. This tells you that you are in calibration mode.
3. The first reading on the display is the incoming voltage. To scroll to other readings, press the Display button. It will scroll through the readings in the following order:
1. Input Voltage – Lights On: Input + Volts 2. Output Voltage – Lights On: Diff + Volts 3. Input Distortion – Lights On: Input + Dist % 4. Output Distortion – Lights On: Reduct + Dist %
4. Start with the Input Voltage Calibration. a. Make sure the Input + Volts Lights Are On. b. Use the mode up / down buttons to calibrate the reading until the reading
matches the actual input voltage. 5. Now Calibrate The Output Voltage.
a. Press the Display button once. b. Make sure the Diff + Volts Lights Are On. c. Use the mode up / down buttons to calibrate the reading until the reading
matches the actual output voltage. (NOTE regenerator is not active during
display calibration) 6. Distortion readings do not normally need calibration, but they can be adjusted the
same way. 7. Press the power button to turn the unit off. 8. Turn unit back on in “normal” mode.

[hkval]

The screw underneath is for output voltage adjustment and the THD reading changes when I adjust that screw correctly. I assume that is because when I get the output to 120 the THD becomes less. I adjust that screw with the meters on reading the output so I know when I am at 120.
I am definitely not a technical expert but I am thinking that if you ever played with that screw on the bottom, you would need to get it back into the correct position before you tried to calibrate the meters. Beyond this, I bow to Dan's expertise.

[Still-One]

Originally Posted by hkval

The screw underneath is for output voltage adjustment and the THD reading changes when I adjust that screw correctly. I assume that is because when I get the output to 120 the THD becomes less. I adjust that screw with the meters on reading the output so I know when I am at 120.
I am definitely not a technical expert but I am thinking that if you ever played with that screw on the bottom, you would need to get it back into the correct position before you tried to calibrate the meters. Beyond this, I bow to Dan's expertise.

I have checked the input and output voltage and compared them to the wall plug and the back panel of the units and they match after a previous correction.

[jdandy]

This afternoon I ordered a fourth PS Audio Power Plant Premier. I moved the one that was installed in my home theater setup to the tube system. I didn't realize until the PPP was out of the home theater system that is was doing a great job of filter out some electronic hash noises that my remote controlled dimmers in the theater are now introducing through my speakers. So a new PPP will go back into this system in a few days.

Here is what I will do with it before I place it into service in the home theater system. I will plug it in, and let it burn in for 24 hours. I will then use my volt meter to measure the output voltage at any one of the rear apron receptacles. While reading the output voltage with the meter, I will adjust the output voltage level to 120 volts using the potentiometer on the bottom. Once this is done I will put the PPP into calibration mode, measure the voltage at the wall receptacle with my meter, and calibrate the incoming voltage reading on the PPP to match the wall voltage. Finally, I will calibrate the PPP output voltage reading to display 120 volts, matching the PPP receptacle output voltage that I previously set. I will make no adjustments to the THD readings.

The above steps describe how my three existing PPP's have been set up. They are performing without any problems.

[Masterlu]

Originally Posted by jdandy

This afternoon I ordered a fourth PS Audio Power Plant Premier. I moved the one that was installed in my home theater setup to the tube system. I didn't realize until the PPP was out of the home theater system that is was doing a great job of filter out some electronic hash noises that my remote controlled dimmers in the theater are now introducing through my speakers. So a new PPP will go back into this system in a few days.

Here is what I will do with it before I place it into service in the home theater system. I will plug it in, and let it burn in for 24 hours. I will then use my volt meter to measure the output voltage at any one of the rear apron receptacles. While reading the output voltage with the meter, I will adjust the output voltage level to 120 volts using the potentiometer on the bottom. Once this is done I will put the PPP into calibration mode, measure the voltage at the wall receptacle with my meter, and calibrate the incoming voltage reading on the PPP to match the wall voltage. Finally, I will calibrate the PPP output voltage reading to display 120 volts, matching the PPP receptacle output voltage that I previously set. I will make no adjustments to the THD readings.

The above steps describe how my three existing PPP's have been set up. They are performing without any problems.

Excellent step by step instructions, thanks Dan.

[jdandy]

Originally Posted by Masterlu

Excellent step by step instructions, thanks Dan.

My pleasure.

[Still-One]

Originally Posted by jdandy

This afternoon I ordered a fourth PS Audio Power Plant Premier. I moved the one that was installed in my home theater setup to the tube system. I didn't realize until the PPP was out of the home theater system that is was doing a great job of filter out some electronic hash noises that my remote controlled dimmers in the theater are now introducing through my speakers. So a new PPP will go back into this system in a few days.

Here is what I will do with it before I place it into service in the home theater system. I will plug it in, and let it burn in for 24 hours. I will then use my volt meter to measure the output voltage at any one of the rear apron receptacles. While reading the output voltage with the meter, I will adjust the output voltage level to 120 volts using the potentiometer on the bottom. Once this is done I will put the PPP into calibration mode, measure the voltage at the wall receptacle with my meter, and calibrate the incoming voltage reading on the PPP to match the wall voltage. Finally, I will calibrate the PPP output voltage reading to display 120 volts, matching the PPP receptacle output voltage that I previously set. I will make no adjustments to the THD readings.

The above steps describe how my three existing PPP's have been set up. They are performing without any problems.

That is exactly what I did with my units when you first sent the directions.

I have also turned off multi-wave as whenever I switch it on, the distortion numbers to up my a few tenths.

[jdandy]

Originally Posted by Stillone

That is exactly what I did with my units when you first sent the directions.

I have also turned off multi-wave as whenever I switch it on, the distortion numbers to up my a few tenths.

Jim.......Is your output voltage remaining stable at 120 volts? If so, perhaps you may just want to leave the display indicating output voltage, so the drifting THD numbers don't drive you nuts.

[Still-One]

Originally Posted by jdandy

Jim.......Is your output voltage remaining stable at 120 volts? If so, perhaps you may just want to leave the display indicating output voltage, so the drifting THD numbers don't drive you nuts.

The output voltage is stable and is corrected to 120. I just question the accuracy of the THD numbers. They sure make no sense.