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previous: kg rg,imo, it always comes dow... -- 4/21/2003 4:24 PM

Re: Interesting theoretical question

4/21/2003 7:54 PM

r.g.

Re: Interesting theoretical question quote: "imo, it always comes down to the grace under overload conditions."     Very good point indeed. You can't just build bigger and bigger amps until they won't ever clip. People will just keep turning them up until they do. So you have to make some explicit kind of limiting happen.     There is some precedence. The old Thomas Vox amps used an adjustable limiter in front of the power amp. It turns out that it was stuck in there explicitly to make the power amp clip in a specific way. The thing is supposed to be adjusted so that the limiter clips the signal, not the power amp running out of voltage headroom. It's only there in the "big head" models, not the smaller amps. And the horns in the speaker cabs make them sound harsh. But if you diable the horns, the Beatle actually sounds pretty good for a SS amp. I think it's because of the limiter.     quote: "another thing i am acutely aware of is the presence of microphonics in tube circuits. not too many ss circuits that are discernably microphonic, yet ALL tube circuits are to a greater or lesser extent! i think the micros add a great deal of ambience and air to the outcome. again, this is preferably in the sound GENERATION stage, not reproduction. "   Ah. Another good one. Really valid. That comes through as a welter of frequency varying delay loops fed back into the signal stream. mmmm.... I have to think about that one. The obvious is to install a number of small mike capsules, but that seems a bit technically backward. A many, many tapped short delay line for feedback?     I bet the DSP modellers don't do that, and they should. It's a natural.     On another note, ceramic caps are furiously microphonic in any low level amp.       R.G.