High-Voltage Power Supplies for Tube Circuits

The DC-Block circuit blocks the small amount of DC from entering the power transformer. What is needed is a huge coupling capacitor, which is simply impractical, as 10,000uF/400V film capacitors might be made, but they would be bigger than a garbage can and cost a fortune. The workaround is to use two high-valued but low-voltage electrolytic capacitors in series with safety voltage clamps that prevent over voltages. In addition, the PCB includes a House-Ground circuit.

The new PS-24 high-voltage power supply uses a full-wave voltage doubler rectifier configuration and an RC filter to provide suitable B+ voltage for a tube power amplifier. The PCB requires a 100Vac to 170Vac secondary winding to power the power supply. The RC filter consists of a 20 to 300 ohm series resistor (R3) and two 470uF capacitors (C3 & C4) in series, effectively making a 235uF/500V capacitor.

The PS-21 holds one high-voltage regulator and two low-voltage regulators. The high-voltage regulator holds the same circuit as the PS-1 and the two low-voltage regulators are similar to the H-PS-1 circuit, but differ in that the rectifier circuit cannot be configured as a voltage doubler.

This is not a replacement for the existing PS-21, but is a brother tube power supply (note the B in 'PS-21B"). Just like the PS-21, the new PS-21B holds three independent regulated power supplies: one high-voltage and two low-voltage regulators. (Note the three heatsinks.) Unlike the PS-21, the PS-21B uses a voltage-doubler-rectifier circuit for the low-voltage regulators. Why? Answer: 6.3Vac secondaries.

GlassWare PS-Tube-SS kit: simple and self-contained, the PS-Tube-SS PCB holds two cascading RC filters for the high-voltage outputs and negative-bias-voltage power supply and 12Vdc power supply for the input stage.

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. 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 is 4.5 by 6 inches and it holds two all-solid-state regulated power supplies, a high-voltage regulator for the tube B+, and a regulator for the tube heaters. Each voltage regulator includes its own raw power supply required for feeding each regulator its raw DC voltage. In other words, except for the power transformer, the PS-1 PCB holds all that is needed to make a superb regulated power supply for tube circuits.

The PS-6 power supply offers a low-voltage bipolar output (up to +/-50Vdc), suitable for solid-state power amplifier or OpAmps; in addition, the PS-6 power supply holds a voltage quintupler that yields a single high-voltage B+ output voltage roughly equal to five times the rail voltage. For example, if the rail voltages are +/-30V, the high-voltage B+ output voltage will be about 147Vdc; if the rail voltages are +/-15V, the high-voltage B+ output voltage will be about 73Vdc.

The PS-15 is a new GlassWare power supply kit for tube fanciers. The PS-15 fills a gap: a power supply for those who need a high-voltage power supply with two sets of regulated low-voltage power supplies (usually for powering heaters).

The PS-18's PCB is small, being only 4in by 4in, but it packs quite a wallop due to the large-valued capacitors used. Two RC-based pi filters smooth the bipolar DC outputs. The heater power supply is regulated, using an LDO regulator, LD1085, and can accept either a full-wave-bridge or voltage doubler or full-wave center-tapped rectifier configuration.

Kit includes 20-page user guide.

The House-GND kit is a simple circuit that helps reduce hum in audio equipment that is attached to a dirty house-ground connection. The diode bridge only connects the two grounds when the voltage difference between them exceeds about +/-1.4V. The small capacitor allows high-frequency noise to find a path to the house ground. The 10-ohm power resistor makes a DC connection between grounds, while still offering some isolation between grounds. The kit is quite small, the PCB being only 1 by 1.4 inches big. Includes all parts, including two hex standoff assemblies and instruction sheet.

The 12Vac PS is a power supply that delivers a regulated 12.6Vdc (or 12Vdc) heater voltage and uses a full-wave rectified octupler rectifier circuit that delivers over 100Vdc from a 12Vac transformer or wallart.