Audiophile Tube Output Transformers

Whether you are into the clean, free spirited "Single Ended" tube output or high efficiency, high power, "Push-Pull" audio, Hammond has the output transformer for you.

Hammond has been producing tube output transformers continuously for over half a century, constantly improving and tweaking their performance. The output transformer is one of the most critical components in a audiophile amplifier. These excellent designs have survived the years and have enjoyed a recent resurgence along with the tube industry.

Please note, the specifications are at FULL OUTPUT power. Many "newbies" to the industry use frequency specification data at milliwatt ranges to inflate their claims. Check carefully when comparing manufacturers specs. Hammond uses -1db roll off points to ensure a typical HAMMOND conservative rating, again at FULL OUTPUT POWER.

To ensure a long life and maximum versatility these units are built to and tested at a Hi-Pot rating of 2,000 VAC!!!!!

Hammond transformers are of EI laminated design.  Hammond does not offer toroidal designs due to their inability to handle tube imbalance and high manufacturing cost.

More importantly, Hammond designs are "ear tested". After a new design has passed Hammond's extensive testing, it's got to sound good too, before Hammond puts it on the market! From Bach to rock & three watts to 280 watts! 

Single Ended Tube Output Transformers

These high quality units are designed for maximum versatility. Designed for both triode or pentode operation - Class A operation. All units include an optional use - 40% screen tap (a proven pentode "sweet spot") for "Ultra-Linear" operation. The ratings shown are at full power and rated plate current.

The lamination iron used is a high quality (M6) grade, silicon steel, for low loss and the lowest possible distortion at bass frequencies. A factory set core cap ensures against core saturation at full ratings. All single-ended output models include multiple interleaved windings to maximize high frequency response. These windings are machine wound with high quality copper wire.

Push Pull Tube Output Transformers

These high quality units are also designed for maximum versatility. All units include an optional use - 40% screen tap (a proven pentode "sweet spot") for "Ultra-Linear" operation. They are designed to be used with most all power output tubes available today. The ratings shown are at full power and rated plate current. Hammond also has added an epoxy potted series to our line for the ultimate in tube output transformers.

HAMMOND Interleaved Windings

The reason for Hammond's sparkling high frequency performance is the use of interleaved windings between the primary and secondary. The number of interleaved windings is optimized to the size (wattage) of the unit. All output models (both single ended and push-pull) include multiple interleaved windings to maximize high frequency response. These windings are machine wound with high quality copper wire The multiple interleaved secondaries are wound (series or parallel connecting them) to match to 4, 8 or 16 ohm load impedances.
The primaries of each model (including the "single-ended" series) include Ultra-Linear taps at the 40% point.

Tube Output Transformers - Esthetics

Hammond has also paid close attention to the "look" of our units as they are as much on display in some designs as the tubes themselves. Hammond units are manufactured with high grade laminations (M6) and machine wound with high quality copper wire. The core is varnished and oven baked to ensure quiet operation - even at high ambient temperatures. Then the end bells are bolted on. These end bells are finished in a tough, low gloss, black powder paint finish to resist scratching. The end bells include knockouts for optional above chassis wiring.