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Re: I wanna tube! Please advise

"Ok...so would I be correct in saying: The higher B+ is (greater Voltage), the higher the modulating voltage MUST be on the grid?"

Even though I understand your logic, I wouldn't call that assumption a rule. It depends on the bias voltage and limiting factors of the valve. So, let's say your tube's bias is set to -70V. Roughly speaking, you can swing grid plus-minus 70volts. You see, you can't allow grid to go positive, otherwise it will start sucking electrons on it and you'll get grid current. Anyways, I am pretty sure you can find two setups at which one of them may have lower B+, but use wider grid swing. The important thing is that you are getting the idea how this work. If you think of the kitchen faucet example, you can imagine that if you have a faucet open for a certain idle current, the amplitude of the swing around that point is determined by either the distance from idle current to a complete shutdown or the maximum available current. Beyond any of these points you will get what's called 'clipping'. This is a fairly loose analogy, but similar boundaries exist for valve. One is grid going positive, another is complete current shutdown with grid being very negative.

"...you kinda have build up the modulated signal until it's big enuf to actually properly 'feed' the main power amp tube."


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