Hello everyone
I'm designing a class A preamplifier with a transformer from Cinemag. A custom one.
It's almost the same output design as NEVE 1073. A gapped transformer but mine is designed to be biased at 90mA.
With a class A design I would expect some amount of Vdc across the primary. I would expect a proper design would be Vcc/2 across the primary.
Am I right about that?
I did some experiment on a Sowter transformer but there was a very small amount of DC across its primary when biased at 70-80mA. About 1-2 Vdc.
I'm designing a class A preamplifier with a transformer from Cinemag. A custom one.
It's almost the same output design as NEVE 1073. A gapped transformer but mine is designed to be biased at 90mA.
With a class A design I would expect some amount of Vdc across the primary. I would expect a proper design would be Vcc/2 across the primary.
Am I right about that?
I did some experiment on a Sowter transformer but there was a very small amount of DC across its primary when biased at 70-80mA. About 1-2 Vdc.
An externally hosted image should be here but it was not working when we last tested it.
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The ideal transformer would show ZERO volts DC drop. That's why they are great.
How do we get both-ways swing? The end of the transformer will kick-up *above* the supply rail as device current drops. (Which means the 2N3055 gets 40V kicks from a 24V supply.)
Real-world transformers have drop, true. But typically 10% to 3% of the total supply in a happy circuit.
How do we get both-ways swing? The end of the transformer will kick-up *above* the supply rail as device current drops. (Which means the 2N3055 gets 40V kicks from a 24V supply.)
Real-world transformers have drop, true. But typically 10% to 3% of the total supply in a happy circuit.
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