High Voltage DC-DC Boost Converter 12V to 150V-420V 170V 230V & 1.25V-12V 6.3V Filament Adjustable Step Up Power Supply 2-Way PSU Regulator Module for Tube Preamp/Nixie Tube

The high voltage circuit of this product does not work. When powered at the recommended 12 Volts, the output voltage was not stable, either with or without a 100 kOhm load. Its current draw from a 12 V supply started at 1.15 Amps at 233 Volts, dropped to 0.36 Amps, would fluctuate suddenly from 0.4 to 0.8 Amps. Thereafter, I could only adjust the voltage from 140 to 178 Volts. Again, the high voltage was not stable.The low voltage circuit of this product does work and is adjustable. I set it to mid-scale, 6.6 Volts.

I like this. I am using this to power a small vacuum tube amp that I built for my guitar. I can not crank to full voltage but I can get it up to about 200 volts and it runs a little warm but is stable and does not introduce noise into the amp. This works much better than having to have a high voltage transformer etc. You can run this off 12v batteries and get off the grid and play a tube amp without heavy transformers etc.

Poor quality, four units tested. HV output does not meet stated spec 30-50mA. Overheats with light load 5mA.

The resistor by the output has color bands that indicate 30ohms, but the board says 3.3 ohms. which one is it?

I should have read all the reviews before buying. Like others have said, when powered up with no load, the highest voltage reached was 290 volts which then very quickly sagged below 200 volts DC. And that's with NO LOAD! Not even close to the specs that say 420 volts. Similarly, the filament voltage is fixed at 10.6 volts and totally not adjustable. I don't recommend this power supply. Amazon should pull producs like this with so many similar bad reviews.

You can see the problem if you look closely at the product photos. Some connecting have too much solder on them IMO.Working so far, but I have yet to put it to the real test powering the microphone preamp I'm building.

While the low voltage portion works well and delivers the 6.3 V I need the high voltage side is not functional. The first unit only put out about 160 V with no load and then sagged to under 90 V with a 7 ma load. Second unit was able to be adjusted to the 250 V no load that I needed but sagged to under120 V with the 7 ma load. Completely unusable. Quality wise parts are crooked on the board and look like it was assembled and soldered by someone with no care for the quality of the unit.I ended up going with 2 separate DC-DC converters. One for 6.3 V and another for 250 V.Finally diagnosed the problem with the high voltage side of the supply. The board has a 220uf and a 470uf electrolytic cap. The caps have the values clearly printed on the surface that is facing up. On the board the values are clearly printed at the location they belong which is about 3/4" apart. The 220uf cap was on the 470uf position and the 470uf cap was in the 220uf position. I removed them and soldered them into the correct position and the HV supply is now working fine. Total lack of QC and obviously not tested. Guessing the entire batch was assembled incorrectly.

The media could not be loaded. Has been my favorite for driving multiple tubes simultaneously, which my project requires. Have ordered a second one for another project.