What's the difference between linear and audio tapers, and why should I care?

Question

I'm stocking up on a variety of potentiometers to keep on hand for my audio projects, and I'm trying to figure out what to buy.

The projects I'm working on seen to call for either linear & audio taper pots. I know the difference between linear and log, but where does audio taper fit into the mix?

Here's what I've researched so far:

• No schematic or parts list has BOTH linear and audio.
• Looking at the Bourns pot spec sheets, they seem to be using linear and audio taper synonymously, but they have different part numbers.
• Sites like mouser and digikey often have, say, a 10k linear and a 10k log, but no 10k audio pot in a search. However, when I search on the Bourns part number for an audio taper, the part is described by mouser as linear taper.
• A lot of audio forums I've been trolling talk about pots as either audio or linear, but they don't appear to be synonymous in the discussions.

See why I'm confused?

So once and for all...can someone school me on the difference between linear and audio taper? I'm also interested to know how to decide which to choose for a particular application, and if they are different enough to have distinct uses, what types of interesting and unexpected results will I experience if I substitute one for the other?

Answer 1

Some rotary Pot's com in Linear, Audio and reverse Audio (where audio=log taper)

Actually it is "quasi"-log scale and not precision logarithm.

Notice it has a rapid transition from two different linear slopes. which gives you more sensitivity over a wider range of audio inputs rather than an apparent Off to ON effect if using a linear pot. If one adjusts audio equipment over a 30 dB range, that might occur in the 1st 5% of a Linear pot.

Such as

Many options may be selected when you order.

Precision Log pots would be mcuch more expensive than

Answer 2

Very simply, with a linear taper, if you turn the pot halfway, the resistance measured on each side will be equal. With logarithmic (aka "audio") taper, that is not true; the resistance follows a logarithmic progression.

Log taper is used because it gives a more natural progression when used for volume control.

Answer 3

The difference between audio & taper is if you want to use a pot that is linear taper it is to provide an adjustment for a device or a feed to a device. An audio taper is a volume control or bass or treble control etc. In a fender amp the control that feeds the adjustment for the balance is linear taper since it adjusts the resistance between the screen grids. The idea that you could use two controls is a good idea and I would recommend this process. Just remember if you do any mods check your work carefully and test your voltages to make sure everything is ok

Answer 4

"Audio Taper" is not strictly defined as it is determined by the particular manufacturer. It's basically a log taper but modified so as to give greater sensitivity around the '0dB' point. eg for a linear fader. For specific tapers I suggest contacting manufacturers who make pots specifically for audio applications eg P&G (Curtiss Wright), ALPS, TKD

Answer 5

According to a Phil Jones bass amp manual, "the Master Volume control is a true "Audio Taper" control so that the level position may be set higher compared to other amps that use a "Linear Taper" control. The Audio Taper control has far more precision in controlling your output and uses the full rotation to control level, unlike Linear controls that just use the first few degrees of turn and give the impression the amplifier has more volume than what it actually has." It's been my experience as a bassist that on amps with Audio Taper pots, the more you turn the master volume control, the louder the amp gets. On amps with Linear Taper pots, the volume increases up to a certain point as you turn the master volume control and won't get any louder past this point.