Multi section winding for exceptional bandwidth and phase shift

FEATURES All our Single-Ended output transformers use the best grade (M6) low-loss grain oriented silicon iron laminations. This ensures minimal distortion and low insertion loss. We wind our Single-Ended output transformers on two chamber bobbins which enables us to provide multiple interleaved winding sections to maximize coupling without excessive inter-winding capacitance. All larger types use 14 interleaved primary / secondary sections for the lowest possible leakage inductance and hence excellent high frequency response. The smaller types, where the leakage inductance is lower we use 7 sections in a single chamber. Single-ended output transformers use a gap in the magnetic circuit. This is needed so that the dc anode current does not cause saturation of the core. Our design process ensures that the specified dc and maximum ac power at the lowest frequency applied together do not saturate the core. The gap is factory adjusted as part of the set-up process.

OPTIONS We can supply 43% screen taps (or any other percentage) for Single-Ended types on request. All output transformers have 4 individual secondary windings which can be arranged for loads of 16, 8, 4 or 1 ohms. The connection arrangements are shown below. Alternatively we can provide a single 4, 8, or 16 ohms or 8 tapped at 4 ohms. Also we can provide twin 4 ohm windings which can be connected in series for 16 ohms or in parallel for 4 ohms. When ordering please be sure to quote the type number, package style and your preferred option for secondary windings and screen tap % as required. Tapped secondary windings will have somewhat increased losses, reduced HF response and reduced damping when the load is connected to a tap.  This is particularly true when a 4 ohm tap on a 16 ohm winding is used.  Please be sure to specify your preferred option if you wish to have a non-standard secondary option or a screen tap %. For size information note the size code letter and see Package Options. (Note style "T" not available for SE types)

CUSTOM DESIGN If we do not list the type you need we will design it. Please let us know your proposed valve type and circuit configuration. We also make replacements for classic amplifiers and circuits. The price normally depends on the size. There is no extra charge for design.