Hammond 125ASE 3 W Single Ended Tube Output Transformer, 25 mA

The 125ASE is the 3 watt entry point of the 125SE universal single ended tube output family. It is designed for general purpose or replacement use (not Hi-Fi) in single ended tube output circuits, a good fit for radio restorers and builders of small one-tube amplifiers who need a single transformer that covers several plate loads and speaker impedances.

Like every 125SE model, it uses a butt stacked core of 29M6 steel with an air gap to reduce D.C. core saturation, and it is rated for a maximum of 25 mA DC bias. The primary (BLU - BRN) presents 10,000, 5,000 or 2,500 ohms depending on which secondary lead you use against the black common:

• WHT: 32 ohms at 10,000, 16 ohms at 5,000 or 8 ohms at 2,500 ohm primary
• YEL: 16 ohms at 10,000, 8 ohms at 5,000 or 4 ohms at 2,500
• GRN: 8 ohms at 10,000 or 4 ohms at 5,000
• ORG: 4 ohms at 10,000

Typical drawing values for the 125ASE are 242 ohms primary DCR, 5.0 H primary inductance and 28.8 kOhm primary impedance at 1 kHz, 1 V. Frequency response is 100 Hz - 15 kHz at full rated power, dielectric strength is 1500 Vrms and the temperature range is -40 to 105C.

It is an open style transformer with primary and secondary leads at least 12 inches long. Dimensions are A 2.81 in (71 mm), B 1.35 in (34 mm), C 1.69 in (43 mm) and D 2.38 in (60 mm), with 0.19 in (5 mm) mounting holes, and it weighs 0.5 lbs (0.23 kg). Made in Canada, RoHS and REACH compliant. For full 20 Hz - 20 kHz response, the 1627-1642 Series is the suggested alternative.