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If that matters to your source, get a better source...

Roscoe

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I can explain it to you, but I can’t understand it for you.

Half of the pot is still in the signal path....

Roscoe

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I can explain it to you, but I can’t understand it for you.

Amen to that.

That’s not the point they were conveying.





These things as volume controls in a preamp stage is ok, as the shunt regulator is followed by amplification stage which also reduces the output impedance of the preamp.

With high input and output impedance how do you implement it between amp and speaker or between preamp and amp?

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Walt

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Walt

Yes, that's EXACTLY the point they're conveying.....



You completely lost me on that last part.... The amplification stage after the shunt volume control has ZERO affect on the fact that the input impedance seen by the source changes as you change volume.... Not sure why you'd want to use a shunt volume control between the amp and the speakers or between the preamp and amp, why would you want to put a volume control between your preamp and amp, isn't that what the preamp is supposed to do anyway?

Roscoe

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I can explain it to you, but I can’t understand it for you.

I am not an expert but this is what I think…..

Typical speaker impedance is 8ohms. Output impedance of the amp has to be 8 oks or lower for proper operation. If you place the shunt regulator with high output impedance, say 1kOhms, between the amp and speaker, would it work properly?

I am using 5-way active system. Preamp does only the volume control. Each speaker’s level needs to be matched still.
For level matching, I have two options:
1. Attenuation network at the speaker
2. Attenuation network between the preamp and the amp along with passive line level crossover network.

It’s my turn for head banging.

If you want to do it between the amp and the speakers, you're pretty much out of luck using shunt attenuators. For a passive resistive attenuator to work properly, it needs to have an impedance that's at least as high as the source impedance, and lower than the load impedance, preferably much higher and much lower... How do you meet both of those criteria between an amp and a speaker? That's what L-Pads are for....

Between the crossover and the amps, it's easy.....

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I can explain it to you, but I can’t understand it for you.

With regards to the assertion that only the series portion of a shunt/series volume control affects sound or "is in the signal path". Not true. In addition to what Roscoe mentioned regarding a variable load being applied to the preamp, the shunt element has current flowing through it. Noise is developed as a result of that current. In my personal experience, the "sound " of that shunt element is audible and not insignificant.

As to Roscoe's question about attenuation a load after a preamp, the purpose would be level matching in a line-level crossover, if I understand the questions asked.

Now the really cool approach would be multiple and identical line stages, each with its own gain control, each filtered to serve the drivers its related amplifier is powering. The challenge is then changing levels without changing relative levels during daily operation, once the balance is determined.

Of course a linear balance pot could be used (or stepped-type control built). The advantage of that approach would be shortening the signal path, always a worthwhile goal.

Stuart