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previous: Bruce Huh? :>)Is Mike talking ab... -- 9/21/1999 4:30 PM

Re: Cap across driver tube

9/21/1999 4:43 PM
Doc	Re: Cap across driver tube I think Andy moved on to the question about a presence control. You can miss the transition if you read it quickly (I did, at first). The small cap across the PI output lines: Small caps will only pass high frequencies (in a k-ohm/megohm environment). The outputs of each leg of the phase inverter are supposed to be equal in amplitude, but exactly opposite in phase. By adding one side's signal to the other, a null is achieved. By only cancelling high frequencies with the shorting link being a tiny capacitor, let's say above 15khz, no high frequency oscillation can be sustained in that circuit. (This explanation isn't for you, Bruce. It's for Mike.)

9/21/1999 4:43 PM

Doc

Re: Cap across driver tube

I think Andy moved on to the question about a presence control. You can miss the transition if you read it quickly (I did, at first).

The small cap across the PI output lines:

Small caps will only pass high frequencies (in a k-ohm/megohm environment). The outputs of each leg of the phase inverter are supposed to be equal in amplitude, but exactly opposite in phase. By adding one side's signal to the other, a null is achieved. By only cancelling high frequencies with the shorting link being a tiny capacitor, let's say above 15khz, no high frequency oscillation can be sustained in that circuit. (This explanation isn't for you, Bruce. It's for Mike.)

Replies:

Eth That tiny capacitor always confused... -- 9/21/1999 6:19 PM