I just "salvaged" a couple of 50k D taper pots from radio cassette recorder. I have understood that D is some sor of audio taper, but what kind.
Janne
I don't think I've heard or a "D" taper.
Put a knob on the shaft and mount it in a box or cardboard so it wont slip.
Mark the rotations %.
Measure the resistance at 25%, 50%, 75%, and 100% (or smaller increments) and make a graph of the taper curve.
Then you will know what the taper is.
John
I've read of them and one source describes it as an accentuated audio taper
http://part.freelab.jp/image/VRcave.gif
Whaddaya know...?
Cool little graph there. Thanks Dai.
john
sure, no problem. I just happened to have that link because I was searching for info on the (apparently slightly unusual) "D" taper to see if I could find some connection between that and old wah pot tapers.
Thanks for the replies. So it's even more logarithmic than A taper.
Janne
Just remember that different manufacturers use different ways to label their pots. Sometimes "A" is for Audio, sometimes its A(linear) B(log) and C(rev log). To know the taper of a pot, you need to read the datasheet from the manufacturer or measure it (as suggested above).
Maybe there are exeptions, but normally American and Japanese manufacturers use b for linear and a for log tapers, European companies use a for linear and b for log.
the other little bit of info I found here:
http://www.rane.com/par-p.html
Quote
audio taper (aka A-taper): Usually 15% resistance at the 50% rotation point.
log taper (aka D-taper): Often used as an audio taper since its 50% rotation point has 10% resistance.
and as far as the wah pot stuff this is what I was looking at:
http://www003.upp.so-net.ne.jp/kazuhee/wahpots.htm
will a D taper (dournes D250K) work ok for a guitar or bass volume and/or tone?
yes
I was looking for a replacement mini potentiometer "D500K" and looked everywhere, but couldn't locate any D tapers.
However, when I contacted Bourns, they knew what it was.
Apparently, they call the "D taper" an "A2 taper," and it is 10% output at 50% rotation, so just about 5 or 10% less output than the standard audio taper (or "A").
(https://i.postimg.cc/LgTw5PVM/a.jpg) (https://postimg.cc/LgTw5PVM)
(https://i.postimg.cc/PphkqdkY/VRcave.gif) (https://postimg.cc/PphkqdkY)
(https://i.postimg.cc/Z9812XyR/TBM-resistance-taper1-1024x974.jpg) (https://postimg.cc/Z9812XyR)
Well, learned something today. Had never heard of D taper before reading this!
buck1107's post got it.
D = log taper ; 10% (of total resistance at mid position)
A = audio taper; 15% to 20% (of total resistance at mid position)
In the old days there were a lot of D's. Perhaps around the late 70's A's started to become the norm.
Both were always available.