Stepped Attenuator Clarification

[westers151]

I cam across this thread and it has confused me with the terminology. As far as I was concerned there are three types of attenuator:

1. Ladder
2. Series
3. Shunt

However in the linked thread he discusses a "series/shunt" attenuator, and says that this is different from a shunt attenuator. My searching has come up with zero results to explain what a series/shunt attenuator is - In fact all my results would seem to suggest that a series/shunt attenuator is the same as a shunt attenuator, as a shunt attenuator has a series resistor on the inputs, and then shunt resistors to ground/switch points.

My only conclusion is that the series/shunt attenuator is just another name for a series attenuator, however I have no proof of this.

Can anyone shed any light on it?

Thanks

 

[Chris Daly]

To attenuate, a series /shunt adds series resistance and at the same time decreases shunt resistance to ground. To restore it decreases series resistance and increases shunt resistance.
The terminology to describe relationship of the placement of each resistor element, is Pads,
The L pad being very common. other types are described here: http://www.uneeda-audio.com/pads/

Many variations are possible when fixed resistance is or is not equal in one or each direction.
As such if each are provided to be deliberately unequal progressive difference
referred to as a taper then occurs. The most famous of which is the logarithmic taper
but if you research you will also find anti log. Linear on the other hand is where
equal resistance is in each branch

Cheers / Chris

 

[westers151]

Thanks Chris

Plenty of reading/research to be done