Sound Performance Lab 9530 Power supply, Tube Vitalizer, Fuses primary voltages 115 V 800 mA

Power supply

Custom made toroidal transformer with five separate wirings.

Voltage selector

Ground-lift switch

Mains filter

Fuses (primary voltages):

115 V: 800 mA

230 V: 315 mA

Special care has gone into the design of the power supply of the Tube Vitalizer. The power supply is the heart of an electronic system:The better it is, the better the whole system works and –in an audio system– the better it sounds.

This power supply is based around a custom made 35 VA toro- idal transformer and is designed to minimize induced hum and noise due to the non existence of an air-gap. All required voltages (230 V, 6.3 V and 2xy15 V, 12 V) have an individual wiring in the transformer and are smoothened separately afterwords.

The primary voltage may be selected between 230 V/50 Hz and 115 V/60 Hz by means of a recessed slide switch on the rear panel.

The rear-panel ground-lift switch may be used where ground loops are causing hum problems. When the Gnd Lift switch is set to off, the circuit ground is no longer connected to the chassis ground. The power cord connector is a 3-wire, U-ground, standard IEC mains connector for a detachable power cord (enclosed) with an inbuilt mains filter.

Transformer, power cord and mains connector have VDE, UL and CSA approvals. The fuse has a value of 315 mA for the primary voltage and 500 mA for the secondary when operated at 230 V/50 Hz.

At 115 V/60 Hz the fuse value for the primary voltage is 800 mA and for the secondary voltage 1000 mA (1A).

On the secondary side of the power supply, an RC combination is used to filter out noise and hum voltages from the mains side. Both half-waves are smoothed with 3000 mF capacitors in the positive and negative voltage path. Both pathes use precision voltage regulators, as deviations of only a few millivolts can result in audible changes such as a diffuse sound pattern.

The operational voltage of the tubes (250 V) is heavily smoo- thened and electronically regulated. The heating voltage (6.3 V) is supplied by an individuell wiring within the transformer. So- called »hum-trimmers« adjust the tubes´ heating voltage and minimize the hum voltages.

Both inputs and outputs of the tubes are smoothened with condensers of high voltage and condenser values (10 µF/ 400 V/5 %) to minimize offset voltages. The tubes are de-coupling at about 10 Hz.

All relays are operated via an individuell voltage regulator and are therefore separated from the audio operating voltage.

18 TUBE VITALIZER