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Old 05-17-2019, 10:52 AM
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Quote:
Originally Posted by Electronic M View Post
Could you have mixed up leads on your transistors?
Ditto. I did that on a magnetic tape preamp once. The transistor type had a reverse lead arrangement instead of the usual EBC sequence. As a result, all the stages were using the emitter as the collector and vice-versa. Instead of three stages with a total gain of 1000, I had three stages with a total gain of 3.

Another thing: I looked at that diagram and calculated the currents from the resistor voltages, and it looks like R5 must be 330 ohms, not 220, to get those voltages. Actually, I think it wouldn't hurt to increase R5 somewhat more than that, so that a larger proportion of the output current is supplied by T2.
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