looking to make a shunt type attenuator 23 step 10k
will be using Z foils for the 2x input/output resistors 10K
what effect has the resistors that go to ground have on the sound if any ?
goldpoint website says that the ROA Speer mouser stock are the best through hole they have tried and for pennies ( pity mouser charge so much for posting a few bits ) cant seem to find them anywhere else
shunt by glenn jarrett, on Flickr
will be using Z foils for the 2x input/output resistors 10K
what effect has the resistors that go to ground have on the sound if any ?
goldpoint website says that the ROA Speer mouser stock are the best through hole they have tried and for pennies ( pity mouser charge so much for posting a few bits ) cant seem to find them anywhere else
shunt by glenn jarrett, on Flickr
In principle they have as much effect as the other fixed resistor because the two together are simply a series pair forming an attenuator. In practice, and at higher levels of attenuation as the switched shunt value becomes lower and lower then any of its 'problem contributions become less. At lower levels of attenuation any 'problem' effects start to predominate.
Unfortunately, this "selling point" is one of the audiophiles' myths that are not technically correct. It is in conflict with Kirchhoff's law and Thevenin's theorem. The resistor to ground contributes to the "equivalent resistance" of the simple voltage divider network (including the amp input impedance), so it is never out of the equation (pun intended), and the voltage to the amp will be affected by the visually "out of the signal path" shunt resistor. In other words, it is not electrically "out of the signal path."
Cheers,
Kurt
Yes, I get that, and this helps Shunt Attenuator Myth
Is my assumption about the noise heading in the right direction at all?
Is my assumption about the noise heading in the right direction at all?
The noise is determined by the Thevenin equivalent circuit, which here is the two resistors
(series and shunt), in parallel.
The popularity of shunt attenuators is a good sign that electricity is poorly taught in school science lessons.
Resistors are the second most perfect/ideal components used in electronics. (The first most perfect components are wires.) Why get worked up about near perfection when much worse problems come from nasty things like transistors and valves?
Anyway, someone who is worried about resistors and knows anything about resistors would use the same resistor technology for the shunt and series elements. This will minimise errors. Ideally, use the same value too - but this makes changing the volume rather difficult unless you use strings of resistors. It makes absolutely no sense whatsoever to use an expensve resistor for the series element and something different for the shunt element.
Resistors are the second most perfect/ideal components used in electronics. (The first most perfect components are wires.) Why get worked up about near perfection when much worse problems come from nasty things like transistors and valves?
Anyway, someone who is worried about resistors and knows anything about resistors would use the same resistor technology for the shunt and series elements. This will minimise errors. Ideally, use the same value too - but this makes changing the volume rather difficult unless you use strings of resistors. It makes absolutely no sense whatsoever to use an expensve resistor for the series element and something different for the shunt element.
looking to make a shunt type attenuator 23 step 10k
will be using Z foils for the 2x input/output resistors 10K
what effect has the resistors that go to ground have on the sound if any ?
goldpoint website says that the ROA Speer mouser stock are the best through hole they have tried and for pennies ( pity mouser charge so much for posting a few bits ) cant seem to find them anywhere else
If possible use ladder type attenuator because maintain the input impedance constant.
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