volume pot
suds mcduff
Think this will do?
http://www.stewmac.com/shopby/product/0128
Oci-One Kanubi
Radio Shack?
'S where I used to get all my parts when I was a working musician.
Now I can afford to go elsewhere (though TRS is still the most
convenient), but back then TRS was all I could afford. Generally
speaking, TRS parts either worked fine or not at all, and if one
didn't work at all I discovered that immediately and took it right
back.
tlbs101
That place is as good as any. Their price is decent, too.
Radio Shack does not carry a 250K audio taper pot, in-store. I know,
because I am currently building a portable PA for my girl-friend.
Tom P.
Oci-One Kanubi
Too bad. I've noticed in recent years that their stock of actual
electronic parts is greatly diminished, to make room for all the
consumer products they now carry.
Benj
It MIGHT do. That's a decent price for a reasonable pot, but they only
seem to have audio taper pots. Depending on whether your J bass is
active or passive it may need a linear volume pot to avoid the rapid
control drop-off problem. If all the volume changes seems to be
happening in a narrow range of rotation you need the other taper.
A "real" source of pots would be:
or
Lots of choices and it pays to know what you are doing.
Derek Tearne
> On Dec 30, 2:36 pm, suds mcduff <sudsmcduff19...@gmail.com> wrote:
> > Anybody know a good place to get a J bass volume pot?
> > Think this will do?
> > http://www.stewmac.com/shopby/product/0128
>
> It MIGHT do. That's a decent price for a reasonable pot, but they only
> seem to have audio taper pots. Depending on whether your J bass is
> active or passive it may need a linear volume pot to avoid the rapid
> control drop-off problem. If all the volume changes seems to be
> happening in a narrow range of rotation you need the other taper.
Huh?
Linear pots are the ones with a rapid drop off problem when used as
volume controls.
Audio taper pots are the ones that give a nice smooth volume reduction.
That's why they call them audio taper.
Some tone controls work better with linear pots - but volume pots? I'd
be surprised if that were so.
I suppose this is where Mike Rieves reveals his new identity and finds a
situation where a linear pot could theoretically work in an audio volume
application - without giving an actual example of an instrument that
uses one.
--- Derek
--
Derek Tearne - de...@url.co.nz
Vitamin S - improvisation from Aotearoa/New Zealand
http://www.vitamin-s.co.nz/
suds mcduff
> Benj <bja...@iwaynet.net> wrote:
>
>> On Dec 30, 2:36 pm, suds mcduff <sudsmcduff19...@gmail.com> wrote:
>>> Anybody know a good place to get a J bass volume pot?
>>> Think this will do?
>>> http://www.stewmac.com/shopby/product/0128
>> It MIGHT do. That's a decent price for a reasonable pot, but they only
>> seem to have audio taper pots. Depending on whether your J bass is
>> active or passive it may need a linear volume pot to avoid the rapid
>> control drop-off problem.
----It's passive.....
If all the volume changes seems to be
>> happening in a narrow range of rotation you need the other taper.
>
> Huh?
>
> Linear pots are the ones with a rapid drop off problem when used as
> volume controls.
>
> Audio taper pots are the ones that give a nice smooth volume reduction.
>
> That's why they call them audio taper.
>
> Some tone controls work better with linear pots - but volume pots? I'd
> be surprised if that were so.
>
> I suppose this is where Mike Rieves reveals his new identity and finds a
> situation where a linear pot could theoretically work in an audio volume
> application - without giving an actual example of an instrument that
> uses one.
----Sht, I thought this was gonna be simple....
RichL
It is. For most people an audio taper pot works fine, passive or
active. You need a 250 K audio taper pot for a passive jazz bass, if I
remember right.
Benj
> Huh?
>
> Linear pots are the ones with a rapid drop off problem when used as
> volume controls.
>
> Audio taper pots are the ones that give a nice smooth volume reduction.
>
> That's why they call them audio taper.
>
> Some tone controls work better with linear pots - but volume pots? I'd
> be surprised if that were so.
Then be surprised, dude! the story that you need an audio taper pot
for volume controls is rife amongst guitarists of all stripes. And I
know where the story comes from. It comes from the fact that given a
usual piece of electronic gear (amp, preamp etc.) where the volume
control is not loaded at all, the story is quite true. A linear pot in
an unloaded situation will give that characteristic rapid drop in
volume for a small part of the rotation.
But life isn't always so simple. If you load the pot slider with
impedance (as is often the case in passive basses with dual volume
controls) suddenly the linear taper is no longer so linear! In fact if
you choose the loading carefully you can make a BETTER audio taper
than an audio taper pot! Don't take my word for it. Ask around some
luthiers and repair dudes. With some basses audio taper works best and
with others linear does. And oddly most often audio taper works best
in tone controls where everyone is convinced that linear is the way to
go.
Look here:
http://sound.westhost.com/project01.htm
> I suppose this is where Mike Rieves reveals his new identity and finds a
> situation where a linear pot could theoretically work in an audio volume
> application - without giving an actual example of an instrument that
> uses one.
Sorry I'm taking over for Mike, even though I did give an example.
Benj
> ----Sht, I thought this was gonna be simple....
Dude! It IS simple. You buy the audio taper pot and install it. If it
works fine, you are home free. If it seems to only control the volume
over a part of it's rotation, you'll have to find a linear pot and
install it. Simple. It's only a couple of bucks each in any case. I
try to keep a couple of both tapers in 250k and 500k pots on hand for
just such issues since they are cheap and you might as well get a few
of them if you are paying for shipping anyway. The only true test to
answer the question "which pot should I use" is to TRY them! Just
tack the wires on with solder until you decide which one is best then
you can really wire it in right. Very educational, but remember it
probably only applies to your bass.
Sir Lurksalot
de...@url.co.nz:
> I suppose this is where Mike Rieves reveals his new identity and finds a
> situation where a linear pot could theoretically work in an audio volume
> application - without giving an actual example of an instrument that
> uses one.
LOL
Derek Tearne
> Then be surprised, dude! the story that you need an audio taper pot
> for volume controls is rife amongst guitarists of all stripes. And I
> know where the story comes from. It comes from the fact that given a
> usual piece of electronic gear (amp, preamp etc.) where the volume
> control is not loaded at all, the story is quite true. A linear pot in
> an unloaded situation will give that characteristic rapid drop in
> volume for a small part of the rotation.
Dude, I know where it comes from too.
Those decibel thingies we use to measure audio volume are logarithmic.
They are logarithmic because of the relationship between power input and
a doubling of volume.
Therefore it should be no surprise that the pots we use to control
volume also need to be logarithmic.
It's simple practical physics.
RichL
You're right Benj, it depends on where you want the most sensitivity.
For volume controls, I suggest that most people like audio taper because
it gives you the most sensitivity near the maximum. YMMV.
I'm with you on tone controls. I've been using audio taper for years on
tone controls 'cause I want that extra sensitivity near the top of the
range on those, too.
Benj
> Dude, I know where it comes from too.
>
> Those decibel thingies we use to measure audio volume are logarithmic.
>
> They are logarithmic because of the relationship between power input and
> a doubling of volume.
>
> Therefore it should be no surprise that the pots we use to control
> volume also need to be logarithmic.
>
> It's simple practical physics.
Dood! Unfortunately it is NOT simple practical physics. Instead it's
complicated electrical engineering! While you are correct about the
necessary logarithmic relationship needed between the voltage output
of the volume control and the apparent perceived loudness, where you
are confused is you are assuming that the voltage output of the volume
control with respect to it's rotation is a function determined solely
by it's taper. Well, when the pot is unloaded (as say the slider is
feeding a 1 meg input impedance preamp as in an active V J bass) that
is exactly correct. But when the slider is loaded with a low impedance
(as can happen when the "volume control" is shorting the pickups as in
a passive vol/vol J bass) one finds that the output voltage vs
rotation is now modified by the added circuit. You didn't read that
reference I provided, did you? To find the actual behavior one would
have to actually do a circuit calculation on the entire wiring. That
can be done using simulator programs such as SPICE, but that is
probably much more information than anyone wants or needs to know.
Most of this stuff has been tried by lots of people before and it
usually comes down to either a linear or audio taper pot in either
250k or 500k values.
Here is a response from an experienced repair guy on Talkbass to a guy
thinking like Derek and asking shouldn't Volume be audio and Tone
linear?
> You would think that that's how it should be, but no.
> Linear taper pots give you a much smoother volume control than audio.
> You don't get that big drop rolling down from "10" to around "8-ish" in
> the rotation.
> I argued about this for a long time before finally deciding to just try it out,
> and linear taper pots definitely work better.
> As far as tone controls though, the linear taper doesn't seem to do very
> much until almost the end of the rotation when used as a tone pot, so
> for that reason, it's best to stick with audio.
Note that it is also more than just taper question but also the kind
of response the player wants from the volume control which is a sort
of personal preference as RichL indicates.
Derek Tearne
> On Dec 31 2009, 5:52 pm, de...@url.co.nz (Derek Tearne) wrote:
>
> > Dude, I know where it comes from too.
> >
> > Those decibel thingies we use to measure audio volume are logarithmic.
> >
> > They are logarithmic because of the relationship between power input and
> > a doubling of volume.
> >
> > Therefore it should be no surprise that the pots we use to control
> > volume also need to be logarithmic.
> >
> > It's simple practical physics.
>
> Dood! Unfortunately it is NOT simple practical physics. Instead it's
> complicated electrical engineering!
Complicated electrical engineering? Replacing a volume pot in a Fender
style passive bass?
Still, sometime in the new year I'll ask some people who really know
this stuff what the deal is. I could also take apart all my instruments
and do a quick check.
> Here is a response from an experienced repair guy on Talkbass to a guy
> thinking like Derek and asking shouldn't Volume be audio and Tone
> linear?
Was this guy named Mike Rieves?
In the couple of instruments I've owned where there has been a rapid
drop in volume near the open end replacing the cheap linear pots with
log pots has always improved things.
Incidentally, I never suggested that tone pots needed to be log pots -
they usually are log pots but that is more to do with saving money (and
reducing chances for error) in the factory than practical electronics.
In fact I'd expect tone pots to work better (have a smoother change
throughout the control range) with linear pots.
> Note that it is also more than just taper question but also the kind
> of response the player wants from the volume control which is a sort
> of personal preference as RichL indicates.
Strangely, even though I effectively use the volume controls on my
instruments as a soft on/off switch (I almost never run at anything less
than open) I prefer a nice smooth drop off over the entire range of the
pot rather than a steep drop at one end.
dusto...@mac.com
wrote:
> Anybody know a good place to get a J bass volume pot?
> Think this will do?
> http://www.stewmac.com/shopby/product/0128
The Guitar Center near me has Fender-bagged pots so, whatever your
Jazz came with (250k audio taper, I think) you can probably get one
there that will have the correct shaft type and length and do a drop-
in replacement. Not the cheapest pot out there but it should be the
right part, first time.
--D-y
suds mcduff
----Ok, thanks.....might just leave as is.....the stem broke off, but
the pot's wide open.....rock n roll!
suds mcduff
----Thanks for the info, I'll check my local GC.....
dusto...@mac.com
> RichL wrote:
Well, rock n roll is all good but I always like my Jazz vols set on
about 9-1/2. Maybe more like 9-1/4, depending on the room.
Someplace about 3/4ths of the way through the previous century, I or
we (me and my bassplayer bud Mike), it seems to me, fixed a pot that
had a broken shaft by getting the shaft out of another pot-- these
were plastic and were held in by a "barb" at the deep end-- where you
could take the jacket off the donor pot and squeeze the barb together,
pull the good shaft out, and snap it into place once the broken pieces
were all out of the donee. Thus saving time and soldering, at least
for the nonce, and of course there were no GC's or for that matter,
much available in the form of bagged Fender parts on display (like I
keep saying, we are in a golden age. Enjoy before the asteroid hits,
folks!).
I hope this isn't a manufactured memory but it does seem real.
Probably depends on just how yours broke as to whether it's not easier
just to put a new one in there; and of course, we had a small pile of
donor parts, too.
"Always trying to make life more complicated!"
--D-y
The BorgMan
> Benj <bja...@iwaynet.net> wrote:
>
>> On Dec 31 2009, 5:52 pm, de...@url.co.nz (Derek Tearne) wrote:
>>
>> > Dude, I know where it comes from too.
>> >
>> > Those decibel thingies we use to measure audio volume are
>> > logarithmic.
>> >
>> > They are logarithmic because of the relationship between power
>> > input and a doubling of volume.
>> >
>> > Therefore it should be no surprise that the pots we use to control
>> > volume also need to be logarithmic.
>> >
>> > It's simple practical physics.
>>
>> Dood! Unfortunately it is NOT simple practical physics. Instead it's
>> complicated electrical engineering!
>
> Complicated electrical engineering? Replacing a volume pot in a
> Fender style passive bass?
Replacing it is easy - choosing the taper that gives you the most log
like behavior at the output, given a particular load - may not be.
--
Aaron
js
and turn it all the way down when to go on break.
Good lord...
"The BorgMan" <m...@me.net> wrote in message
news:Xns9CFF76D5...@130.133.4.11...
RichL
> ...Or you could just turn the pot all the way up for proper gain
> staging, and turn it all the way down when to go on break.
>
> Good lord...
And let the sound guy worry about controlling dynamics...
The BorgMan
september.org:
Or just remove it completely...
Some people care about smooth even operation across their volume pot,
others don't.
--
Aaron