Euraudio PS1S specification

Welcome to the Euraudio PS1S specifications, in which you can read about the system requirements (application criteria), operation and technical data of the PS1S.

The PS1S is a symmetrical (+/-) power supply with a ground loop breaker circuit, and is recommended for home-made audio amplifiers. Please find the PS1Sc assembly instructions here, which contains information about the sizing of the filter capacitors and fuses.

PS1S system requirements

What kind of amplifiers can the PS1S be used for?

It can be used for amplifiers that need a dual or in other words symmetric (+/-) supply voltage. Note: The PS1S can be used for the Euraudio Euraudio LDA17mc, LDA17hc, LDA172mc, and LDA172hc ultra low distortion, low noise audio amplifiers as well.

Up to what amplifier power can it be used?

The recommended maximum amplifier power is 2x125 W or 1x250 W (speaking of class B or class AB amplifiers).

Theoretically it could be used up to higher amplifier power, since there is at least an 10 A rectifier bridge is in. With the supplied heatsink it can withstand about 8 A continuous current at 60 °C ambient temperature. However there is only room for 2 pcs of max. 35 mm diameter filter capacitors in the PCB, and most of the electrolytic capacitors of this size have a ripple current specification that will limit the allowed maximum amplifier power.


The  PS1S rectifies the two sinusoidal AC voltages connected to its input, then it smooths it by using filter capacitors, thus generating the symmetric (+/-) supply voltage that is necessary for most audio amplifiers.

To void ground loops, the grounding of the PS1S has a star-like arrangement, furthermore the PS1S contains a so-called ground loop breaker circuit, which prevents hum from appearing through the earthing conductor, if devices with earth ground protection against electric shock are connected to your amplifier, and the chassis of your amplifier is also earthed.

At the input of the rectifier bridge, there is space for a snubber RC network (R91, C91), that may be sized in order to decrease the oscillation between the leakage inductance of the transformer and the capacitance of the rectifier together with stray capacitance of the transformer. Installing the snubber network is not mandatory, and its sizing procedure is not part of the documentation. However, if you're interested, here's an article about it:

Technical data

At 25°C ambient temperature unless otherwise noted.

Bridge rectifier input voltage: max. 2x60 VAC

Allowed continuous output current at 60 °C ambient temperature: max. 8 A (limited by the heatsink of the bridge rectifier)

Recommended amplifier power: max. 2x125 W or max. 1x250 W (class B or class AB)

Size of applicable filter capacitors:  snap-in type, max. 35 mm diameter


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