Hammond 1760C 5W Single-Ended Output Transformer, 3 Secondary Taps

The 1760C is a 5 watt single-ended output transformer for tube guitar amplifiers, built as a drop in replacement for original Fender units. The series table lists it for the Bronco, Champ, Princeton, Vibro Champ and Harvard, similar to Fender part numbers 125A35A, 022905 and 125A3A, across Blackface, Silverface, AA764, AB764, Tweed, 5C1, 5E1, 5F1 and Vibro Blackface chassis.

It offers a dual 5,000/8,000 ohm primary and three secondary taps at 3.2, 8 and 16 ohms, compared with the single 3.2 ohm secondary the series table lists for the 1750C. Maximum primary DC current is 40mA. Typical frequency response is 70Hz to 15KHz (0/-1dB referenced at 1KHz) with distortion under 1% at 70Hz. DC resistance is 359.90 ohms (primary blue-red), 272.08 ohms (primary brown-red), 0.278 ohm (black-yellow), 0.624 ohm (black-green) and 1.491 ohm (black-white). At 1.0 kHz, 1.0 V, primary blue-red measures 23.0H (132K ohm) and brown-red 16.2H (92K ohm); leakage inductance is 719.5mH (blue-red) and 583.0mH (brown-red).

The 1760C is bobbin wound, open style, with all leads at least 9 in long. Primary leads are red (common), brown (5000 ohm) and blue (8000 ohm); secondary leads are black (common), yellow (3.2 ohm), green (8 ohm) and white (16 ohm). Dielectric strength is 1750VRMS and the temperature range is -40 to 105 degC.

Drawing dimensions are A 2.813 in, B 1.560 in, C 1.683 in and D 2.375 in, with a 0.187 in slot. Shipping weight is 0.55 lbs (0.25 kg), and the part is RoHS and REACH compliant.