Not Your Average Inductor: The Original BBC Design Transformer Style 7 tap L3 manufactured exclusively for Falcon Acoustics.
For many years we’ve supplied a huge variety of air-core, e-core and ferrite chokes to many OEM’s to suit the requirements of their crossovers. However, after an initial discussion with Jerry Bloomfield of Falcon Acoustics we realised that what he was looking for was going to be be a first for Volt Loudspeakers.
Falcon Acoustics are well known and respected for their faithful reproduction of the BBC LS3/5A monitors. Which, as well as the B110 driver, T27 Tweeter, include the FL6/23 crossover that feature the transformer style 7 tap L3 inductor. We were struck by the meticulous detail that Jerry and Malcolm Jones had gone to to reproduce the LS3/5A to it’s demanding BBC specification not only in terms of sound but also in appearance and choice of materials. Consequently using a more modern and simplistic inductor was simply not an option for the Falcon design team.
Jerry approached us as he believed we could solve quality control issues and manufacture this inductor consistently. All Volt inductors are wound to tight tolerances but we had not produced one with 7 taps. Each tap, incidentally, has different values that must be within a tolerance of +/-5 %.
Working out how such an inductor could be built wasn’t challenging, however developing a method that guaranteed the consistency required throughout a large production run was going to be tricky. The main barrier was that these transformer style inductors are clamped together after they have been wound and so an amount of pressure is applied to the core. The amount of pressure means that the values of each, some or all of the taps changes, subsequently throwing the inductor out of tolerance. One could play around with the tightness of the clamp for each individual piece but this is simply not practical or cost effective for a large production run.
Firstly Steve and David realised that an existing machine needed to be modified to cope with the number of taps and then spent time designing a bespoke piece of tooling that allowed a consistent amount to pressure to be applied to a number of inductors at anyone one time. After a period of development, they were satisfied that these BBC Design transformer style 7 tap L3’s were consistently within tolerance and would meet the high quality standards of the Falcon Design Team.
Volt manufacture the BBC Designed transformer style 7 tap L3 inductor exclusively for Falcon Acoustics. It has certainly broadened our knowledge of how to manufacture inductors that are of a more complex design. For further information about the product or indeed the Falcon LS3/5A please visit their website that contains a wealth of information about the product’s rich heritage and how to purchase a pair.