1750H Hammond PP Übertrager Deluxe Reverb 125A1A 022640

Hammond 1750H – Deluxe Reverb output transformer with 6.6 kΩ to 8 Ω

The Hammond 1750H is a paper-wound push-pull output transformer for Deluxe and Deluxe Reverb circuits. It provides 6.6 kΩ plate-to-plate, a fixed 8 Ω output and a documented 20 W transformer rating.

Hammond confirms Fender references 125A1A, 022640 and 041318. Including these numbers in the product name supports accurate service-part identification.

Suitable applications

• Fender Deluxe Reverb amplifiers using reference 125A1A or 022640
• Deluxe Reverb 65 Reissue amplifiers using reference 041318
• Documented Deluxe and Deluxe 68 Custom Reverb applications
• Push-pull stages using two 6V6 valves and approximately 6.6 kΩ
• Guitar amplifiers with a fixed total loudspeaker load of 8 Ω
• New amplifiers in the 20 W transformer class with a suitable operating point

Technical data

Product type

Push-pull guitar-amplifier output transformer

Model

Hammond 1750H

Documented amplifier families

Deluxe, Deluxe 68 Custom Reverb and Deluxe Reverb 65 Reissue

Documented references

125A1A, 022640 and 041318

Primary impedance

6.6 kΩ plate-to-plate with centre tap

Secondary impedance

8 Ω

Transformer power rating

20 W

Amplifier topology

Push pull

Typical output-valve complement

Two 6V6 valves in total at a suitable operating point

Winding type

Paper winding

Primary inductance

Approx. 21.4 H at 1 kHz, 1 V and open secondary

Secondary inductance

Approx. 27.36 mH at 1 kHz, 1 V and open primary

Primary DC resistance

Approx. 428 Ω between brown and blue

Secondary DC resistance

Approx. 0.410 Ω

Primary leakage inductance

Approx. 13.54 mH at 1 kHz, 1 V and short-circuited secondary

Frequency response

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

Distortion

Less than 1% at 70 Hz under the documented test conditions

Dielectric test

1,500 V RMS

Temperature range

-40 to +105 °C

Lead length

At least approximately 229 mm or 9 inches

Dimensions

Approx. 94.2 × 61.0 × 58.6 mm

Mounting centres

Approx. 79.5 mm

Mounting-hole diameter

Approx. 4.75 mm

Hammond shipping weight

Approx. 0.73 kg

Manufacturing note

Made in Canada according to the current component drawing

Lead connections

Blue

First primary connection to one output-valve plate

Red

Primary centre tap to B+

Brown

Second primary connection to the opposite output-valve plate

Black

Secondary common or loudspeaker ground

Green

8 Ω loudspeaker connection

Phase

Follow the applicable Deluxe Reverb circuit exactly where global feedback is used

Selection by reference and chassis

The reference number is an important selection criterion but does not replace verification of the exact chassis. Confirm the 6.6 kΩ load, 8 Ω total speaker impedance, mounting, lead colours and feedback phase before installation.

Do not substitute a 4 or 16 Ω loudspeaker without recalculating the output stage. A different secondary load significantly changes the plate-to-plate impedance seen by the two 6V6 valves.

Comparison with the Hammond 1760H

The Hammond 1750H has a fixed 8 Ω output. The Hammond 1760H also uses 6.6 kΩ, a 20 W rating and a paper winding but provides 4, 8 and 16 Ω secondary taps.

Safety notes

Lethal plate voltage is present on the primary circuit. Install the transformer with complete touch protection and fully discharge the amplifier before service work.

Questions about selection and use

Which output transformer suits a Deluxe Reverb using 125A1A, 022640 or 041318?

Hammond 1750H is intended for these documented Deluxe Reverb references and provides 6.6 kΩ plate-to-plate, a fixed 8 Ω output, paper winding and a 20 W rating.

Which 20 W push-pull output transformer suits two 6V6 valves and an 8 Ω loudspeaker load?

Hammond 1750H is a suitable starting point for a correctly designed two-6V6 stage requiring approximately 6.6 kΩ plate-to-plate and a nominal 8 Ω loudspeaker.

Can the Hammond 1750H be used in a 65 Deluxe Reverb Reissue or 68 Custom Deluxe Reverb?

Yes, the Hammond 1750H can be used in a documented version when the reference, 8 Ω output, mounting, lead arrangement and amplifier circuit correspond to the particular unit.

Is the Hammond 1760H a suitable alternative when 4, 8 and 16 Ω are required?

Yes, the Hammond 1760H is the documented multiple-tap alternative with 4, 8 and 16 Ω, while the Hammond 1750H has only a fixed 8 Ω output.