I usually build audio transformers, but until now always for tube output. For tube line output I use “EI” European core, normally with 20 mm x 20 mm section (4 square centimetres section). I also use the 16 mm x 16 mm, always wit Grain Oriented transformer steel M-6.
Now I am interested in build LO 1166 replica for NEVE Microphone preamplifier
I can remember their specifications:
200 : 600 Ohms
1 : 1,7 turns ratio (+4dB)
Core = 20 x 20 mm approximately
I don’t know if the core is Grain Oriented M-6 or Ni Iron, that’s right, I have only M-6….!
Gapped, (when I make gapped cores I put a very thin sheet of paper).
When I make tube output transformers, the primary winding has some thousand turns, (because it shows some KOhms impedance). But in this case the primary shows only 200 Ohms (and secondary 600).
Someone can provide me any suggestions regarding the better number of turns to start experimenting?.
Thanks
Miquel
Now I am interested in build LO 1166 replica for NEVE Microphone preamplifier
I can remember their specifications:
200 : 600 Ohms
1 : 1,7 turns ratio (+4dB)
Core = 20 x 20 mm approximately
I don’t know if the core is Grain Oriented M-6 or Ni Iron, that’s right, I have only M-6….!
Gapped, (when I make gapped cores I put a very thin sheet of paper).
When I make tube output transformers, the primary winding has some thousand turns, (because it shows some KOhms impedance). But in this case the primary shows only 200 Ohms (and secondary 600).
Someone can provide me any suggestions regarding the better number of turns to start experimenting?.
Thanks
Miquel