Hammond 1638SEA 30W 10000 Ohm Single-Ended Triode Output Transformer

The 1638SEA is a 30 watt single ended output transformer with the highest primary impedance in its series, 10000 ohms, and a 90 mA DC bias rating. It was designed principally for high impedance triode tubes, with the 211 and 845 listed as suggested triodes, making it a fit for builders of large single ended triode amplifiers.

The 1627-1642 Series is "over designed" for high fidelity, single ended, Class-A tube output circuits. Each transformer is enclosed (shielded) and uses high quality (M6) grain oriented silicon steel laminations, with a gapped core to reduce core saturation in Class-A amplifier circuits. Insulated flexible leads are 8" minimum, and the case uses four slot, chassis Type "X" mounting with 0.20 x 0.38 in (5 x 10 mm) slots.

Unlike most of the series, the 1638SEA does not include a 40% screen tap. The secondary provides 4, 8 and 16 ohm taps. Listed primary inductance is 88 Henrys. Typical drawing values include 337 ohm primary DCR, 107 Hy primary inductance and 700 k primary impedance at 1 kHz, 1 V, with secondary DCR of 474, 591 and 792 milliohms. Frequency response is at least 20 Hz to 20 kHz at full rated power (+/- 1 dB max.); hipot test 2000 VRMS; temperature range -40 to 105C.

Overall dimensions are A 3.75 in (95 mm), B 4.94 in (125 mm), C 4.56 in (116 mm), D 3.00 in (76 mm) and E 3.81 in (97 mm), and it weighs 11 lbs (4.99 kg). Made in Canada. RED connects to B+ and BLUE to the tube plate. RoHS and REACH compliant, UPC 623980008349.