Power supplies, particularly high-voltage power supplies, are often the big stumbling block to a successful completion of a tube-based audio project. Getting a PCB and all the capacitors, diodes, and resistors needed to populate the PCB is only half the problem. The other half is getting the power transformer. Well, with the new Tr-PS-2 power supply both problems are solved at once, as the Tr-PS-2 holds its own power transformer, a MagneTek FS120-300.
The Tr-PS-2's PCB is only 5 " by 2.8 " and, like all GlassWare PCBs, is extra thick (0.094 in), US-made, with heavy 2 oz-copper traces. The PCB holds a simple RC pi-filtered high-voltage power supply. Each rectifier is in series with a 10-ohm resistor, both of which are shunted by a high-voltage capacitor to reduce RFI creation.
The Tr-PS-2 power supply uses four solid-state, ultra-fast-recovery rectifiers, a simple RC pi-filter to achieve a fairly quiet B+ voltage, which delivers a maximum about 165Vdc @ 150mA or 330V @ 75mA, depending on the option chosen and the wall voltage, as its output voltage is not regulated. If the external load draws 30mA and the 1k RC resistor is used, the output voltage would be either 145Vdc or 300Vdc, depending on the jumper option chosen. The 5W series resistor (300, 1k, 1.5k, 10k supplied) can be replaced by an external choke.
Kit includes all the parts (capacitors, rectifiers, resistors), including the user guide, the transformer and four sets of standoffs and screws and O-rings. It is available in two power-supply voltage ratings: 250V or 450V. The 250V capacitors are 470µF in value, while the 450V capacitors are 150µF.