AC Mains Line Power Filter LPF-4000

 456.00 552.00 Incl. VAT
 380.00 460.00 Excl. VAT

LPF-4000 AC Mains Line Filter



Based on the big success of its predecessors DC Blocker assembled in case and Combined DC Blocker & EMI/RFI filter, the offered here AC Mains Line Power Filter further exploits their strengths and goes beyond with new features and capabilities.


Block-schematic of LPF-4000

As it is shown on the Block-Schematic below, LPF-400 has a two-stage EMI/RFI filters structure plus a new generation of DC Blocker (DC Blocker NG).
The first stage EMI/RFI filter is built using the Triad Magnetic’s High-Power CMF (Common Mode Choke) CMT-8121. This choke is rated at 20A and thus can handle most power amplifier’s current demands. The first stage filter works in “common” and “differential” modes simultaneously which effectively decreases both types of interference.
On the same PCB is placed the DC Blocker NG (New Gen) – because of the new approach used in this module, its DC blocking capabilities are raised up to 4.5V while retaining the same power throughput as its predecessors.
As it’s shown on the Block-schematic and on the pictures of the unit, LPF-4000 has 4 AC Mains outlets and the mutual impact of each other is greatly diminished by use of dedicated second-stage EMI/RFI Filters for each output. The second-stage filters utilize the Wuerth Electronics’ high quality nanocrystalline chokes. Thanks to their parameters is possible to design a low-pass filter with low enough corner frequency while preserving a frequency response characteristic without sharp spike at the start of the rolloff region.
The last PCB in the set is used for surge protection and relay control.
As can be seen from the block-schematic, there is a varistors group which is used as a surge protector (in conjunction with the Main Fuse after the IEC inlet).
The Power ON/OFF switch placed on the unit’s back panel controls a high quality power relay which connects/disconnects the power lines from the IEC inlet.

As probably everyone knows, the proper wiring is crucial to reveal the full unit’s performance. That’s why special attention is paid to the process of design and physical wiring of the LPF-4000 power filter.
The concept of “star-wiring” topology is heavily implemented here – on the pictures above are visible the three “star-wiring Centres” – for Live, Neutral and Ground (Protective Earth) lines. The first two are arranged as Barrier Terminal Blocks, placed on the PCB of DC Blocker and 1-st stage EMI/RFI filter, while the last is a Ground Distribution Buss-bar, connected to the bottom of the metal chassis.

LPF-4000 is enclosed in steel sheet case, high-quality black powder coated. Beneath the case are placed 4 solid aluminum feet with rubber dampening rings.
On the front side is mounted solid aluminum panel (black or white hard anodized) with red LED indicator for normal operation.

Black and White front panels are available

On the back side panel are placed 4 AC Outlets (various types are available), IEC inlet with fuse holder and ON/OFF switch.

Back panel with C14 IEC inlet, ON/OFF switch and 4 AC Outlets

In most cases along with the low-power audio devices (DACs, Network streamers, CD players etc.) there are power amplifier(s) which draw much more power than the second stage EMI/RFI filters can provide. That’s why, a variation with only two second stage filters is available. The first two AC outlets are connected directly to the output of the high power first stage EMI/RFI filter and are dedicated for high-power consumers.

LPF-4000 with two direct (high-power) outputs


For the cases when higher than the normal handled power is needed, there is a variation of the filter with C20 IEC inlet, capable to withstand up to 15A.

LPF-4000 with C14 or C20 IEC inlet without Relay Power Switch Board

In this case the C14 or C20 IEC inlet is directly connected to the DC Blocker & First stage EMI/RFI board (no ON/OFF switch and Power relay board).

LPF-4000 without Relay Switch Board


LPF-4000 with two direct (high-power) outputs and C20 IEC input (no ON/OFF relay board)


The LPF-4000 line power filter can work with various input AC voltages and frequencies – the widespread 230V/50Hz and 115V/60Hz are supported off-the-shelf (just leave a note for the required type during the checkout process). If your input AC Mains voltage is different than the above-mentioned ones, send us a question for confirmation via the site’s contact form and we’ll discuss the possibilities for filter’s manufacturing.
The different AC Mains input voltages goes along with the different AC outlets used in the countries all over the world. We’re happy to announce that LPF-4000 supports wide variety of AC outlets: Standard EU Schuko, French, UK, US, Australian and Switzerland types.

Additional information

Weight 4.55 kg
Front panel color

Black, Silver

AC Outlet type

EU Schucko, French, UK plug, US plug, Australian, Switzerland

Input AC inlet type

C14 IEC with Power Switch Board, C14 IEC without Power Switch Board, C20 IEC without Power Switch Board

Number of secondary EMI/RFI filters

2 filters + 2 HP outputs, 4 EMI/RFI filters