One Electron magnetic products have been designed to fill the need for high-quality yet affordable audio transformers and chokes that are not normally available elsewhere. This is why we have concentrated a bit more on the esoteric types. If you are interested in having One Electron add a new product, contact us, but keep in mind we only mass-produce our products. One Electron does not do custom transformer designs. One Electron transformers and chokes are sold only through Antique Electronic Supply (retail) and CE Distribution (wholesale).

The datasheets for each type have specifications, application information, mechanical drawings, and suggested mounting holes.

Single-Ended Audio Output TransformersUBT picture

The UBT series of single-ended output transformers are well-known for their clean, detailed sound, and broad bandwidth.




 Max. DC
Primary Current




 1600 ohms

 4, 8, 16 ohms

160 mA

 15 W


 4800 ohms

 4, 8, 16 ohms

 110 mA

 15 W


 3000 ohms

 4, 8, 16 ohms

 110 mA

 15 W

Plate Retard Coils/High Quality Audio Chokes

PRC-1, 2:

The PRC series of audio chokes are intended for shunt-feed single-ended output stages, but are also useful where a high quality filter choke is needed. Each has two windings that can be connected in series or parallel.




 Max. DC





 5.5 H

230 mA




 22 H

115 mA




 12 H

150 mA



 48 H

75 mA

 PRC-3 N/A
15 mA

Power TransformersBFT1B picture

All One Electron power transformers are designed for critical audio applications and include an electrostatic shield between primary and secondary and a copper flux band to reduce stray magnetic fields. The international primary accomodates 100, 110, 120, 200, 220, 230 and 240 volt mains at 50 or 60 Hz.


 Secondary #1

 Secondary #2

 Secondary #3

Secondary #4 



 770 VCT, 340 mA, with taps at 520 VCT

 5 VCT, 4 A

 6.3 VCT, 9.6A

 6.3 V, 4 A

Note: for archival purposes, data on the earlier BFT-1 and BFT-1A transformers is given here: BFT1A_10.pdf.

One Electron transformers are distributed by Antique Electronic Supply. They can be reached at:

Go to the One Electron home page