1760E Hammond Übertrager 5E3 Princeton Tweed deluxe 125A10B

Hammond 1760E – 15 W push-pull output transformer with three speaker taps

The Hammond 1760E is an open-frame, centre-tapped push-pull output transformer for valve guitar amplifiers. Hammond specifies an 8.5 kΩ plate-to-plate load, a 15 W rating and secondary outputs for 4, 8 and 16 Ω. It is intended for correctly matched 5E3 Tweed Deluxe, Princeton and Princeton Reverb output stages using a pair of 6V6 valves.

Compared with the Hammond 1750E, the 1760E is the flexible multi-tap bobbin-wound version: the 1750E has a single 8 Ω output, while the 1760E adds 4 and 16 Ω connections. Always confirm the schematic, mounting pattern and feedback phase of the exact amplifier before treating it as a replacement.

Suitable applications

• Repair or new builds based on the 5E3 Tweed Deluxe circuit
• Princeton and Princeton Reverb push-pull output stages with a compatible primary load
• Two-6V6 guitar amplifier projects requiring a transformer rated around 15 W
• Fixed or switchable speaker outputs for 4, 8 or 16 Ω loads

Technical data

Product type

Push-pull output transformer for valve guitar amplifiers

Primary impedance

8.5 kΩ plate-to-plate, centre-tapped

Secondary impedances

4, 8 and 16 Ω

Transformer power rating

15 W

Frequency response

70 Hz to 15 kHz, 0/-1 dB referenced to 1 kHz

Winding construction

Bobbin wound

Primary inductance

21.60 H typical at 1 kHz, 1 V with the secondary open

Primary DC resistance

154.40 Ω brown–red and 159.20 Ω red–blue, typical

Secondary DC resistance

0.410 Ω black–yellow, 0.540 Ω black–green and 0.830 Ω black–white, typical

Dielectric strength

1,500 V RMS

Construction

Open chassis mounting with leads at least 9 in or 229 mm long

Dimensions

Approx. 82.6 × 53.0 × 50.7 mm (A × B × C)

Mounting

Approx. 71.5 mm mounting centres; slots approx. 4.75 × 7.62 mm

Connections

Primary winding

Brown and blue to the output-valve plates, red centre tap to the high-voltage supply

4 Ω output

Black common and yellow 4 Ω tap

8 Ω output

Black common and green 8 Ω tap

16 Ω output

Black common and white 16 Ω tap

1760E, 1750E or 1750EP?

Hammond 1760E

8.5 kΩ plate-to-plate, 15 W, bobbin wound, 4, 8 and 16 Ω outputs

Hammond 1750E

8.5 kΩ plate-to-plate, 15 W, bobbin wound, 8 Ω output only

Hammond 1750EP

8.5 kΩ plate-to-plate, 15 W, paper wound, 8 Ω output only

Selection and installation notes

Connect the speaker to the tap carrying the same nominal impedance. Deliberate mismatch changes the primary load reflected to the output valves and should only be used after checking the operating point, dissipation limits and complete circuit. Insulate every unused secondary lead separately.

The 15 W figure is the transformer's rating, not a guarantee of amplifier output power. In amplifiers using global negative feedback, primary phase must also follow the circuit; reversed plate leads can turn negative feedback into positive feedback.

Lethal voltages may be present on the primary wiring. Installation and testing require suitable expertise, a disconnected mains supply, safely discharged filter capacitors, touch protection and adequate insulation clearances.

Questions about selection and use

Which output transformer suits a 5E3 Tweed Deluxe output stage with two 6V6 valves?

Hammond 1760E is a suitable choice for a 5E3 Tweed Deluxe output stage with two 6V6 valves when the circuit calls for an 8.5 kΩ plate-to-plate load and a 15 W transformer. Its secondary taps support correctly matched 4, 8 or 16 ohm speakers.

Which output transformer provides 4, 8 and 16 ohm taps for Princeton Reverb circuits?

Hammond 1760E provides an 8.5 kΩ centre-tapped primary for push-pull operation plus separate 4, 8 and 16 ohm outputs. Check the schematic, mounting dimensions, lead colours and feedback phase of the specific amplifier before installation.

Can the Hammond 1760E replace the Hammond 1750E?

Yes, when the circuit and chassis match the 8.5 kΩ plate-to-plate load, 15 W rating, bobbin winding and physical dimensions. Compared with the 1750E, the 1760E adds 4 and 16 ohm secondary taps while retaining the 8 ohm connection.

Is the Hammond 1760E suitable for a push-pull pair of 6V6 valves?

Yes, the 1760E is a technically suitable option for correctly designed 5E3- and Princeton-style operating conditions. The 8.5 kΩ primary load and selected speaker tap must still match the supply voltage, bias conditions and circuit.