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In the Forum: Audio Discussions
In the Thread: Initial thoughts about new/old Lamm ML2s
Post Subject: The demagnetizing coils in ML2 – a false alert.Posted by Romy the Cat on: 9/23/2008

 Paul S wrote:
I don't know what you mean by "the demagnetizing coils in its output transformer".  What does this mean?

I do not have any plans about ML2. A friend of my asked me to help him with his ML2. So, I did end up the amps sitting in my room. Since I opened them last time (in 2001) I learned a lot and begin to understand a few things that I did not understand then. I have written (I think it was in David Bearing thread) some that there is a technique of dynamic demagnetization the transformer core with injected could to prevent the core from early LF clipping.  I remember Lamm said in his ML2 design “the special measures were taken to prevent the ML2’s output transformer from saturation” - so I fell that it would be worth to see how it is done. Upon looking at the ML2 circuit it does not look like Vladimir used any demagnetizing coils in his OPT. The primaries go to plate of output tube and to the grid of the regulator. The secondarys go the binding posts. Everything else is pretty straight forward…  So, it look like that there is no dynamic demagnetizing in ML2. It is said in a way, as it the ML2 did use it then the depth of the demagnetizing would be VERY interning parameter to measure.

The Cat

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