High Voltage DC-DC Boost Converter 12V to 150-420V & 1.5-12V Step Up Power

Worked well for a very short time, then failed. Provides 200V under no load, but output drops to near zero volts under even light load (a few 10s of mA.)

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.

Works Perfectly ! Coil must be glued by silicon!

I bought this as a general-purpose high-voltage supply. I measured the efficiency at various loads, using a 12.5-volt power supply. The efficiency is about 30%, very low for a switching power supply. It dies with a load less than 5 watts. The supply is based on a 40-year-old design which probably explains its poor performance. Do not buy this unit.

I purchased this for a tube preamp B+ supply that I built. I was only able to get 200 volts output! That was no load! if I loaded it to even a few millamps it would put out even less high voltage an got hot. I tried different diodes in the bucking circuit but it just did not perform as expected. Electronics has been a hobby for more than 60 years.I waited beyond the return window to start my project. My mistake I should have tested it as soon as it arrived. I don't think this thing could perform as advertised, it needs higher rated parts to put out the 400 volts claimed. Meanwhile I wasted $20

really should work at 5 vdc , to be valuable. All these supplies need 12 vdc and tubes have 6.3 v . So 12 v is another power supply for a power supply . Might as well stay 60 hz Also USB is everywhere 5 vdc 2 amps . yet no 90-200 v supplies made Can this be modified for 5-7 vdc input

Very good

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.

Does not function as advertised.