Plitron Toroidal TransformersElectrostatic loudspeakers require high voltages on their plates to move the charged membrane. Therefore a step-up transformer is needed to convert low amplifier output voltage into the high voltage used in electrostatic loudspeakers. Designed by Menno Vanderveen, these impedance matching toroidal transformers utilize the same technology as Plitron’s acclaimed wide bandwidth toroidal output transformers for tube amplifiers. Short form specifications are shown below. For full, individual spec sheets, in html, click part number buttons; for pdf versions click in download section.

Through original research, Plitron has developed a range of round-loop materials utilizing gapless toroidal cores, making them an ideal choice for toroidal inductors.

Gapless toroidal cores smooth out the hysteresis curve, and extend the linear operating portion. They are often less expensive than gapped cores, and can resolve issues associated with the air gap. Stray fields are lowered across the board, and remove any ‘hot-spots’ especially near the gap. There is less likelihood of cross-talk and interference to other commencements. A continuously wound core contains no cut edges to vibrate, thus noise reduction is not an issue.


Model Numbers PAT4133-ES PAT4134-ES
Step-up Ratio 1:50 1:75
Power, Nominal 80 W 80 W
Input, Nominal Power 4 ohms 4 ohms
Secondary Inductance 719 H 1600 H
Secondary Leakage Inductance 15 mH 22 mH
Primary DC Resistance 0.1 ohms 0.1 ohms
Secondary DC Resistance 190 ohms 273 ohms
Secondary Internal Capacitance 700 pF 800 pF
-3dB Power Bandwidth w/ Rep in-series 1.05 Hz to 26 kHz 0.52 Hz to 23 kHz
Case Black Polyamide 140 x 66 mm 140 x 66 mm
Download pat4133-ES pat4134-ES