Hammond 1750A 3.5W 25K Single-Ended Guitar Amp Output Transformer

The 1750A is a 3.5 watt single-ended output transformer from the 1750 series of tube guitar amplifier replacement parts. The series ordering table lists it for the Fender Reverb, as similar to original part number 22921, with a 25000 ohm primary and an 8 ohm secondary. (The part page describes the primary as 22800 ohms.)

Like the rest of the 1750 range, it is designed for drop in replacement of the original unit, constructed to look similar to the original factory part where possible, and built with materials and design specifications kept as close as possible to the original to preserve the stock "tone". The winding type is bobbin.

The drawing rates frequency response at 70 Hz to 15 kHz (0/-1 dB reference @ 1 kHz), with distortion of less than 1.5% @ 70 Hz. Typical values at 1 kHz: primary DCR 1065 ohms (Blue-Red), secondary DCR 0.966 ohm (Black-Green), primary inductance 31.0 H with 190 kOhm impedance, secondary inductance 39.09 mH with 157.05 ohm impedance, and 1.54 H leakage inductance. Dielectric strength is 1500 Vrms and the temperature range is -40 to 105 C.

The 1750A is an open style transformer with minimum 6" long primary and secondary leads. Drawing dimensions are A 2.000" ±0.063, B 1.440" ±0.125, C 1.745" ±0.063 and D 1.719" ±0.063, with a G dimension of 0.187" ±0.015. Shipping weight is 0.4 lbs (0.18 kg). It is made in Canada and RoHS and REACH compliant.