A few years back this became an interesting exercise. Living in Cape Town at the time we had Eloff Transformers, well reputed and pricing well below the industry average (through retail stores). They did not at that stage design, repair or build toroids for the industry. This may have changed now though as of 7th May 2017. After some searching, lots of searching and hair pulling I finally came across this gem, Swiftheat in Aeroton, Johannesburg. OK, so I haven’t used them – at the time I had another solution but have bookmarked them for future use. Two facts: Fast, friendly, knowledgeable response. A 1kVA toroidal for audio use cost half of that of a local supplier (Cape Town) who didn’t have stock anyway. (currently eBay lists 400VA toroidal 50V CT 25-0-25 at about R500, R1300.00 shipping).