Any inexpensive way to get regulated 120 volts AC power? I tried a Tripp Lite Smart LDC 1500 UPS. IT said it's output was 120 volts, and it had Automatic Voltage Regulation. Well it turns out it doesn't really regulate the voltage. If it goes up over 128 volts it reduces it by something like 14%. So the ups won't work. Any suggestions? My AC is with in tolerance, But it jumps around some. In the winter its not to bad. Its more like a drift. Starts out high in the morning, and gets lower all day. But now that's it has gotten really hot here, and we, and everyone else in the area are using their air conditioning, it jumps up and down all day. It's still within 5%, but it makes my bias current change all the time, and it drive me crazy. Wish I could afford a Perfect Wave.
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No. It's because the B+ voltage varies with the AC line voltage, and the Bias current follows. It is all with tolerance and sounds fine. But It makes me crazy.
I took your advice. I got a used , working Sola MCR1000 for $75.00 on ebay. Regulates to 120 volts +/- 3%. This one regulates to 121.9 volts. So it's not the 120 volts I hoped for. But mostly I wanted a stable voltage, and that it does.
It buzz's pretty good. But I wanted it for testing in the shop.
I am happy with the results. With a staple AC line voltage, my B+ is perfectly stable, and doesn't drift at all. Oh, B- is stable also. But best of all, my bias current for the 300B tube is perfectly stable also. I set them at 70ma, and they stayed right there. No drift. Not even with the music. Stayed set at 70ma. perfectly.
I just needed to know that all the voltages drifting was caused by the AC line voltage changing, and not the fault of something I did wrong building it, or a bad part. I am now satisfied.
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