Hammond 125GSE 25 W Single Ended Tube Output Transformer, 100 mA

The 125GSE is the highest-power model in the 125SE universal single ended tube output range, rated at 25 audio watts. It is designed for general purpose or replacement use (not Hi-Fi) in single ended tube output circuits, and fits builders of high-power single ended amplifiers who need generous DC current handling.

Rated for a maximum of 100 mA DC bias, the 125GSE is built on a butt stacked 29M6 steel core with an air gap to reduce D.C. core saturation. Its primary (BLU - BRN) presents 10,000, 5,000 or 2,500 ohms depending on which secondary lead is used with 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 are 53.2 ohms primary DCR, 8.23 H primary inductance and 51.6 kOhm primary impedance at 1 kHz, 1 V. Secondary DCR runs from 127 milliohms (black - orange) to 294 milliohms (black - white). 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 open style with primary and secondary leads at least 12 inches long. Dimensions are A 4.15 in (105 mm), B 2.88 in (73 mm), C 3.46 in (88 mm), D 3.45 in (88 mm) and E 2.50 in (64 mm), with 0.20 in (5 mm) x 0.38 in (10 mm) mounting holes. It weighs 6 lbs per the series table (shipping weight 6.25 lbs / 2.83 kg). The 125GSE is made in Canada and RoHS and REACH compliant.