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

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.

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?

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.

I purchased one of these, and the filament voltage side on that one would not adjust down lower than the 12 v input. Output voltage adjusted just fine. Returning items to Amazon is a huge PITA because of my location, so I just ordered a second unit (while willing to suck up the cost of the first one).Second one arrived today, and it has the exact same problem - the filament voltage side will not adjust. It just remains stuck at the input voltage. (Again, the output B+ voltage side adjusts.)This time, with two of these to return, it's now worth the time and money to return both units for refunds.Shop around somewhere else to find one of these types of power units. Clearly these are just a waste of time and money. I'd give this ZERO stars, if that was possible.

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.

I'm using this to drive a 12AX7 tube circuit. There is a small-amplitude 14 Hz sawtooth on top of the HV, which shows up in the audio output. Bought two of these at the same time and both show this behavior.