• Mullard 5-10 economic magnetics kit
  • Mullard 5-10 mains transformer with screen
  • Mullard 5-10 EL84 PP Output transformer
  • Maplin replacement 200V @ 50mA and 6.3V @ 1.5A
  • The popular PWHT01 2 x 250V @ 80mA 5V @ 2A 6.3V @ 2A CT


If you are looking for a valve transformer, whether you need a mains transformer, choke or an audio output transformer for your project, one that is built to last, and of the best quality available for a reasonable price, then Primary Windings is the place to come.

We specialise in the design and manufacture of transformers and chokes for valve based designs.


The transformers we make are both high voltage (HV) mains, needed to supply the higher voltages in a valve circuit and low tension (LT) mains, generally for the heater voltages. 

We also manufacture high quality output transformers, that will meet your exacting requirements.

We are a small UK company, that prides itself on producing valve transformers and chokes at the highest build quality, at a reasonable cost. We believe that the products we make are here for good, not for the landfill. We make them to last, so the designs you make will last as long as there are valves to fill the sockets!

It makes us proud to think the hard work that we put into making a quality British product will still be around long after we have.

Design Service

We are capable of undertaking the design and manufacture of most transformer and choke designs. If you submit your requirements, we will design a transformer or choke . This service if free of charge.

Once the you have accepted the design, we will quote you for making it.


We enjoy making valve circuits, mostly radios. So we will add some articles on practical valve construction, along with any articles we come across that we feel you might enjoy.

There is something magical about valves, when you first power up your circuit for the first time, and see the glow from inside the glass, it still fills me with wonder and amazement how they work.

To make them work, you need the power to make them glow, and that’s where we come in; supplying the transformers and chokes to give the valves their power.

Recent posts

  • The Mullard 3-3, an excellent choice for a first amp - Although this was my second Mullard amplifier build, my first being the 5-10, this was quite an eye opener for me. Again I built to the Mullard layout for a control-less  amplifier, as described in the Mullard circuits for Audio amplifiers book.…
  • Creating the Mullard 5-10 magnetics - 5-10 Output transformer From the start I wanted to create an output transformer for the Mullard 5-10, not as a cheap option, but a quality product that would allow a 5-10 builder, or any design using EL84’s in a push…
  • Now available the 5-10 Output transformer and mains transformer - It is with great pleasure that we are now able to offer our version of the Mullard 5-10 Output transformer and mono mains transformer. We have spent quite some time ensuring that the specifications of both units were to a…


Here, you can find Datasheets for all our products.