For those who like to make their own gear and experiment....There are now some new Carnhill Transformers available.
Input transformer 600R:15k (standard and Mu-metal can types) [CA-18-VTB2381 / VTB2381M]
Output transformer 15k:600R [CA-18-VTB2380]
Mains transformer dual primary, 6.3v and 200v secondary [CA-18-VTT2378]
500 Henry, 5mA Choke [CA-18-VTB2379]
12:1 DI Input Transformer [CA-18-VTB9072]
Our on-line store ships worldwide: Audio Maintenance Limited Transformers and Inductors
Colin Audio Maintenance Limited - Support Zone