looking for some pot - Page 2

Apex Jr · 22nd February 2010, 07:03 PM

Infinia...

Call me, 818 248-0416

These pots have dual 4 pin connections, maybe you can help
me finding out how to check for the taper.

Alps only have a dual 3 pins.

Steve @ Apex Jr.

msb64 · 07:42 PM

Quote:

Originally Posted by Apex Jr

Infinia...

Call me, 818 248-0416

These pots have dual 4 pin connections, maybe you can help
me finding out how to check for the taper.

Alps only have a dual 3 pins.

Steve @ Apex Jr.

Going by Infinia's previous description:

Set the 25K pot to halfway, and use a multimeter to take a resistance reading.
If it reads 12.5K it is linear, if it reads 5K it is audio taper.

Use the pins that show a range of 0 - 25K when the pot is rotated clockwise.

Apex Jr · 22nd February 2010, 08:04 PM

OK...
Didn't work.
Pot has a center detent

0 0 0 0

using the bottom row
pins 2 and 3 in center detent is 25K
pins 2 and 3 all the way to the right 25K
Pins 2 and 3 all the way to the left 5 ohms - 7 ohms

Also in center detent I get 25K withs pins 1 and 3

Xoc1 · 22nd February 2010, 08:15 PM

When choosing pots I always found that a linear pot used with a law faking resistor gives a good performance. Also if you don't like the attenuation slope you can always change the value of the law faking resistor to give you more adjustment at your preferred listening level.
Personally though I use a stepped switch attenuator - limited adjustment - hair shirt etc, but once listened to its hard to go back

Apex jr
looks like you have a linear 50K pot. to use this as a volume control try putting a 5 to 10K resistor between the centre wiper pin and the ground pin.

infinia · 08:46 PM

Hi Steve
on 4 pins/section pots usually 1 of them is a dummy
you should be able to find the wiper easily as its resistance changes in relation to the outer 2 that stay at a fixed resistance of 25K. note this

Q for you on these 2 pots then
Alps 3 pins per section no detent?
Nobel 4 pins/section with center detent?

this should explain everything (see figure 4 here) wiper center is at 120 degrees on chart

thetube0a3 · 22nd February 2010, 08:49 PM

my APT-Holman preamp has a stepped attenuator. I think 32 pos?

I like it, but not really necessary for this amp project.

infinia · 09:01 PM

Quote:

Originally Posted by Xoc1

looks like you have a linear 50K pot.

central detent... thinking its a balance control thingy
If it's 50K he should of measured that already
maybe one pin is fixed halfway?

"you can always change the value of the law faking resistor" I think so ...that's probably what most of the manufacturers do (so a linear would be the most flexible to get IMO)

chatziva · 22nd February 2010, 09:47 PM

call me crazy but cheapo carbon pots sound great to me...!

thetube0a3 · 22nd February 2010, 09:51 PM

"call me crazy but cheapo carbon pots sound great to me...!"

Not looking for a sound difference. conductive plastic ones are said to be far more durable.

infinia · 22nd February 2010, 09:56 PM

Quote:

Originally Posted by chatziva

call me crazy but cheapo carbon pots sound great to me...!

hi Crazy
Indeed esp the1 Meg ones are the best

22nd February 2010, 08:32 PM	#15
infinia diyAudio Member Join Date: May 2005 Location: Californication	Hi Steve on 4 pins/section pots usually 1 of them is a dummy you should be able to find the wiper easily as its resistance changes in relation to the outer 2 that stay at a fixed resistance of 25K. note this Q for you on these 2 pots then Alps 3 pins per section no detent? Nobel 4 pins/section with center detent? this should explain everything (see figure 4 here) wiper center is at 120 degrees on chart __________________ like four million tons of hydrogen exploding on the sun like the whisper of the termites building castles in the dust Last edited by infinia; 22nd February 2010 at 08:46 PM.

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22nd February 2010, 07:03 PM	#11
Apex Jr diyAudio Member Join Date: Jun 2002 Location: Torrance, Calif	Infinia... Call me, 818 248-0416 These pots have dual 4 pin connections, maybe you can help me finding out how to check for the taper. Alps only have a dual 3 pins. Steve @ Apex Jr.

22nd February 2010, 08:04 PM	#13
Apex Jr diyAudio Member Join Date: Jun 2002 Location: Torrance, Calif	OK... Didn't work. Pot has a center detent 0 0 0 0 using the bottom row pins 2 and 3 in center detent is 25K pins 2 and 3 all the way to the right 25K Pins 2 and 3 all the way to the left 5 ohms - 7 ohms Also in center detent I get 25K withs pins 1 and 3

22nd February 2010, 08:15 PM	#14
Xoc1 diyAudio Member Join Date: Nov 2008 Location: Devon UK	When choosing pots I always found that a linear pot used with a law faking resistor gives a good performance. Also if you don't like the attenuation slope you can always change the value of the law faking resistor to give you more adjustment at your preferred listening level. Personally though I use a stepped switch attenuator - limited adjustment - hair shirt etc, but once listened to its hard to go back Apex jr looks like you have a linear 50K pot. to use this as a volume control try putting a 5 to 10K resistor between the centre wiper pin and the ground pin.

22nd February 2010, 08:49 PM	#16
thetube0a3 diyAudio Member Join Date: May 2008	my APT-Holman preamp has a stepped attenuator. I think 32 pos? I like it, but not really necessary for this amp project.

22nd February 2010, 09:47 PM	#18
chatziva diyAudio Member Join Date: Jun 2007 Location: UK	call me crazy but cheapo carbon pots sound great to me...!

22nd February 2010, 09:51 PM	#19
thetube0a3 diyAudio Member Join Date: May 2008	"call me crazy but cheapo carbon pots sound great to me...!" Not looking for a sound difference. conductive plastic ones are said to be far more durable.