DIY Audio Home

Small power supply using the Tentlabs MEC (Mini Electronic Choke)

Tentlabs (Guido Tent with the help of Menno Vanderveen) created a series of electronic choke emulators, intended to replace big heavy filter chokes in power supplies for tube amplifiers.

I used one of the small ones, the MEC-100, in my 3B7 amplifier.  This part is rated at 100mA and emulates a 10H choke.  You can find full details about it on the Tentlabs website here.  It performs flawlessly as a filter choke in a capacitor-input filter for a B+ supply.

I also designed a small power supply PCB that uses the MEC-series chokes:

It's quite small - 90mm x 50mm - but can generate a 100mA B+ supply for a preamp or smaller power amp.  Here is the circuit:

You can also download a PDF file of the schematic here.  The PDF schematic also has details about what components to use and how to connect things.

You can configure the board to use a full-wave bridge using silicon rectifiers, or a full-wave CT, or a tube full-wave CT, or even a hybrid tube/silicon bridge.  It just depends on how you connect the inputs, and which rectifiers you install.  There are more detailed hookup instructions on the PDF schematic.

Here is a better look at the bare PCB:

You can buy the PCB and the MEC-100 in my eBay store.