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Re: Primary z of output transformers

2/8/2000 12:23 AM
Randy Jamz
Re: Primary z of output transformers
There is no one 'proper' primary impedance. You can use virtually anything you can get your hands on. By checking a tube manual, you can see 6L6's are listed as having a primary Z of anywhere from 10K to 3800 ohms, with corresponding plate voltage and power output variances. Decreasing the impedance will increase the output (to a point), increase the bandwidth, and increase the THD. Pick a happy compromise. 6CA7's have been listed at 4K, while EL34's list at around 6600 ohms. Of course, you'll be limited to what is available commercially. If you find something around 4-5K, take it. What counts for a little more is the core size. I'll give up a little output for a smaller core that will saturate easier.