Maybe someone can put me out of my misery and answer these mic-transformer related questions. I've been trying to get definitive answers for several weeks with not too much luck.
#1 Is it possible to damage a mic transformer by applying DC (eg resistance meter)? I read somewhere that the DC from meters can magnetise the core (seems unlikely to me, but...). If so, can a tape head demagnetiser (wand) be used to reverse the process?
#2 What are the relative merits of applying the +48v to the centre tap as opposed to using 6k8 resistors? (there may be a link with #1 here?) The Gyraf uses resistors, some others use the centre tap. If the resistors are left in circuit, they have a bearing on the input impedance, so may affect the design of other parts of the input circuit. Isn't it better not to be hanging things off the primary if it can be avoided?
#3 The Sowter website lists transformers for mic level and line level. Is there any disadvantage in using a line level transformer for mic input, if the turns ratios are the same? Eg can the 4383 (LA-2A input type) be used as a mic transformer?
#4 Any web resourses that go into audio transformer design in some detail?
There are more, but this thread is long enough already! :grin:
Cheers,
Steve
#1 Is it possible to damage a mic transformer by applying DC (eg resistance meter)? I read somewhere that the DC from meters can magnetise the core (seems unlikely to me, but...). If so, can a tape head demagnetiser (wand) be used to reverse the process?
#2 What are the relative merits of applying the +48v to the centre tap as opposed to using 6k8 resistors? (there may be a link with #1 here?) The Gyraf uses resistors, some others use the centre tap. If the resistors are left in circuit, they have a bearing on the input impedance, so may affect the design of other parts of the input circuit. Isn't it better not to be hanging things off the primary if it can be avoided?
#3 The Sowter website lists transformers for mic level and line level. Is there any disadvantage in using a line level transformer for mic input, if the turns ratios are the same? Eg can the 4383 (LA-2A input type) be used as a mic transformer?
#4 Any web resourses that go into audio transformer design in some detail?
There are more, but this thread is long enough already! :grin:
Cheers,
Steve