Quilter Zero crossing simulation

Started by Steben, June 15, 2019, 12:03:10 PM

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Steben

#20
https://www.youtube.com/watch?v=pFSX93aPzmw

Watch this. Note how abruptly these amps clip and how the X over starts to add to the wave already clipped.
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bool

An x-over dosent "add" to the signal. Technically, it "subtracts".

Imho: You can tailor the abruptness and add a bit of "sag" and "thinning" with a compressor much better (which this circuit is when you look at peak waveforms across time; it's just a lousy compressor because it kills the very tone that you usually want to keep).

I have already been where you are going and decided it's a dead end (for me).


But, by all means, do what thou wilt!

Elektrojänis

Quote from: bool on June 18, 2019, 06:25:05 AM
An x-over dosent "add" to the signal. Technically, it "subtracts".

Even that depends if you are lookin at it on just time/amplitude or analysing the spectrum on the frequncy domain. Even if it takes some of the fundamental away it will still add overtones too.

And no... I'm not really even saying if it is good or not. It probably depends on what kind of personal preferences you for the tone. (But you knew that anyway...)

bool

It will take RMS down in time. There's no question about that.

The question is do you want that particular overtones? Or would you want some other kind.

Steben

Quote from: bool on June 18, 2019, 06:25:05 AM
An x-over dosent "add" to the signal. Technically, it "subtracts".

Imho: You can tailor the abruptness and add a bit of "sag" and "thinning" with a compressor much better (which this circuit is when you look at peak waveforms across time; it's just a lousy compressor because it kills the very tone that you usually want to keep).

I have already been where you are going and decided it's a dead end (for me).


But, by all means, do what thou wilt!

True, it subtracts power.

again, even super amps like deluxes or ac30s are subject to rejection. Some like it some dont.
Reminds me of n youngs fuzzy tube amp sound.

fact is, much tube amp mojo is about stuff like this. Sometimes one can but conclude there are just as many souls favouring old school tube tech as there are opponents. Threads like what is amp like distortion reveal this.
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teemuk

#25
There is a big difference whether the crossover distortion appears only when the amplifier is overdriven to clipping, as in class-AB tube amps, or if the crossover distortion appears due to, say, insufficient bias, as in poorly designed solid-state class-AB circuits.
In the first case harmonic / intermodulation distortion of crossover distortion is added to harmonic / intermodulation distortion created by clipping, in second scenario crossover distortion adds harmonic / intermodulation distortion to otherwise "clean" signal, and also in greater magnitudes the lower the signal amplitude is.

IMO, latter type of crossover distortion, which kinda just sounds like a layer of static "buzz", is the reason for poor overall reputation, the other type dynamically changes overall timbre of the entire distortion and works as a dynamic, touch sensitive effect. Part of reasons why tube amps are reputed to have "feel". Magnitude also matters: People may prefer a little bit of "swirl" in the overdrive tone but the associated "blocking distortion" effect is not commonly perceived as very musical, perhaps because it affects other than overdriven and distorted signal.

BTW, the youtube video nicely illustrates the "noise gate" -effect (e.g. Boss HM-2, Peavey JSX): At extreme levels of overdrive the waveform rises and descends so abruptly that any crossover dead time becomes largely negligible. This is why the simple diode crossover distortion noise gate has very little effect as introducing crossover distortion and more effect as gate for low magnitude signals, which would be largely just noise due to extremely high gain.

bool

Diodes-gaste is ok ... because it's fast. And easy on the budget.