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SMPS DC Filter P089ZB Kit

$ 14.00

The PO89ZB, an inline DC filter for SMPS wall warts, preamps, HPAs, Korg NuTubes, B1, etc.  

This filter is limited to single rail 48V DC, 3A applications.  The kit contains top-quality parts as selected by the circuit’s designer which includes KEMET ESH477M050AH4AA or Nichicon UHW1H471MPD capacitors and top-quality Bournes  inductors RLB0912-2R2ML.  The kit’s PCBs are fabricated using 2oz copper and tinned thru-holes for low noise operation and ease of assembly.

Note that the kits will use either the Nichicons or Kemets depending on availability as these are often difficult to source. Both are considered the top two choices for low-ESR caps for the circuit and users will be happy using either.

For more information about the filter see the thread.

Included in this kit:

  • PCB
  • R1, R3: 0.04R or 0.05R 5% 1W precision current sense resistors, LS 12mm
  • R2, R4: 953ohm 1% 0.25W resistor
  • C1, C2: 470 uF 50V capacitor, LS 5mm and Diam 10mm
  • L1, L2: 2.2uH 7.5A 0.10R inductor, LS 5mm and Diam 9mm
  • D1: 68V Unidir TVS 600W, DO-204 pkg

Note - Photos include parts available at the time of publishing. Individual components are subject to change based on availability.



  • Can this filter be used for the 5A Meanwell 24V power supply the store sells? No, as this kit is only rated to 3A no matter the DC voltage.

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SMPS DC Filter P089ZB Kit

$ 14.00 USD

Customer Reviews

Based on 17 reviews
Doug C.
Great for my Nutube NEB-2

Just what I needed. It eliminated all hum and hiss from NuTube harmonic generator board so I could use standard wall wart for 12VDC power. Its small size allowed it to be mounted in a wooden cigar box that I mounted the NuTube in.
DIY store was great to work with when the USPS lost it in the mail the first try.

Effective SMPS filter

Thanks to the excellent filter my FE2022 build is exceptionally quiet, which enhances its ability to capture fine details, N + THD < -90dB with 48V SMPS.
Many thanks to Mark and diyStore.

You are a star!

Beautiful little kit. The sound of the B1 Korg is more detailed.

Jaap B.
Great with NuTube preamp

Sounds great with NuTube preamp and Purifi Eval1.

Jason C.
Wish I would have read it wasn't built

Kind of funny that I missed that part, but the packaging was great parts are sealed and on time.

Mark W.

Was surprised how well this works, bought several, used one on my 6-24 crossover. To my ears, bass has more authority and image is more vivid . Will try the other on the Korg B1. Going to get 2 more for new projects. Highly recommended