This product is made to order, with a lead time of approximately one month. Input voltage can be selected between 117V–230V.

Unlike other field coil speakers, JENSEN speakers require matched pairs with separate power supplies for high and low voltages. The speaker sockets are differentiated by 5-pin and 6-pin connectors.

At Onmon Lab, we developed power supply using 811A and 6DJ8 vacuum tubes, operating as a current regulator. Both units provide an output of 12W each.

Compared to using rectifier tubes, this design ensures superior current stability, allowing the speaker’s performance to be fully realized.

Why Stabilize Current Instead of Voltage?

Field coils gradually heat up during operation, increasing their DC resistance (DCR). If a voltage regulator is used, the current drops as resistance rises, reducing speaker efficiency.

With vacuum tube current regulation, the voltage automatically adjusts to compensate for rising DCR, maintaining consistent speaker performance.

Why Are Vacuum Tubes Superior to Resistors?
While resistors and capacitors alone can produce the desired voltage, resistors—like coils—generate heat during operation. This increases DCR, reducing current flow to the coil.

Vacuum tubes, however, exhibit minimal temperature drift after warm-up and negligible voltage drop. By combining tubes, we ensure stable output current, with voltage dynamically adjusting to DCR fluctuations.

The listed price includes vacuum tubes. We can also provide dual high-voltage or dual low-voltage configurations—feel free to inquire.

Product images are for illustration only. Actual wood case colors and dimensions may vary.
Wood frame options: Walnut, Red Oak, Cherry, etc.