pots?

JPMo · #1 11-21-2011, 06:39 AM

Hey guys,
I have a pretty simple question. Sorry for my lack of knowledge but I was wondering if changing the pots make the tone and volumes knobs more "sensitive"? I have a squier jazz bass and I want to get a broader range of tone differences. Could this be a amp issue as well?

BassBron · #2 11-21-2011, 06:58 AM

Hello JPMo,

Read your question, and I have posted a similar question, from which I have not received a reply. I did some research on the topic, and have found that this is quite a common experience for passive bass guitars. Not sure if your bass is active or passive? You can change the pots (which I have not done yet) from 250 to 500 kilo Ohms?? and some of the pots are linear and others are logarithmic.
Not sure if you can still follow me at this stage? I can look it up, as I have recently obtained three books on guitar building and design. Regarding your question of this being an amp issue, I can report that my line 6 amp has pre-programmed outputs that I can choose and adjust on the amp. My BB414 tone adjustment is not great, but the amp makes up for everything in my case. I hope it helps?

Crater · #3 11-21-2011, 07:45 AM

Yes, you can change pots, but the difference in tone will be minimal and not worth the money and/or hassle of swapping them out. I would suggest something else if you're looking to change/tweak your tone. An EQ pedal would be my first suggestion, but if you're playing through a small practice amp, that would be the first thing I'd upgrade.

JPMo · #4 11-21-2011, 07:46 AM

Thank you, my bass is passive but I want to know what a 500 kohm pot does as apposed to a 250 kohm. I guess I will just have to research it myself.

JPMo · #5 11-21-2011, 07:48 AM

Ok thanks crater, I am currently playing through a small practice amp actually haha guess I need to do some shopping

Lo-E · #6 11-21-2011, 07:54 AM

The 500K pot will give you more output and a brighter tone (ie: more treble). The reason for this is that a smaller value pot (250K) will isolate your signal from ground by only half as much as the larger pot will, and this effect is most noticeable in the treble frequencies.

The extent of this effect, and how noticeable it is depends mostly upon the impedance of pickups and how they interact with the pot.

Pots are cheap, and the job is easy to do if you know how to solder. Try it and see how you like it. You can always change it back if you don't.

WhiteNinja · #7 11-21-2011, 07:57 AM

Quote:

Originally Posted by JPMo

Thank you, my bass is passive but I want to know what a 500 kohm pot does as apposed to a 250 kohm. I guess I will just have to research it myself.

500kohm will give you more range and a more brighter sound. I had 500k pots in my precision and swapped them out for 250k CTS pots, and the result was a less brighter sound and less "clank".

96tbird · #8 11-21-2011, 08:20 AM

Pots won't make enough difference for you that it is worth it. Have you played with pickup height?

Raise the bridge pickup so there is about a nickel's space between it and the strings, solo it and check that it sounds good with no funny chorus like sound ( too close). Set the side to side angle so all strings have the same loudness. Now set the neck pickup so it has the same volume output as the bridge; it will be farther away from the strings. That should help give you more noticible tonal blends.

You may need to add more rubber foam under the pickups so you can set them higher, just get some heavy black foam weatherstrip from the hardware and cut to size. Try this first and an amp may help, but it can only work with what is coming into it. Have fun.

96tbird · #9 11-21-2011, 08:39 AM

Quote:

Originally Posted by Lo-E

The 500K pot will give you more output and a brighter tone (ie: more treble). The reason for this is that a smaller value pot (250K) will isolate your signal from ground by only half as much as the larger pot will, and this effect is most noticeable in the treble frequencies.

The extent of this effect, and how noticeable it is depends mostly upon the impedance of pickups and how they interact with the pot.

Pots are cheap, and the job is easy to do if you know how to solder. Try it and see how you like it. You can always change it back if you don't.

But be careful in how you interpret this. The output of the pickups is all you have. A 500k vol means the vol cut happens slower across the sweep and it will affect overall tone a bit adding brightness, and more signal will pass. You will hear more highs too and highs just sound louder to our ears.

A 500k tone pot will sound a bit brighter true, but doesn't boost output.; not that its not worthwhile.it may get clanky, but you just roll it back down. Play with the pickup setup first. With passive, quality of pickups and their height is key, get the max clean output out of them first. Then decide if you want to try pots.

SGD Lutherie · #10 11-21-2011, 10:40 AM

Get linear taper pots.

Lo-E · #11 11-21-2011, 11:47 AM

Quote:

Originally Posted by 96tbird

They will not give more output. You just have the wrong concept in mind. The output of the pickups is all you have. A 500k vol means the vol cut happens slower across the sweep and it will affect overall tone a bit adding brightness, not output. You are hearing more highs and they sound louder because highs just sound louder to our ears.

A 500k tone pot will sound a bit brighter true, but doesn't boost output.; not that its not worthwhile.it may get clanky, but you just roll it back down. Play with the pickup setup first. With passive, quality of pickups and their height is key, get the max clean output out of them first. Then decide if you want to try pots.

The OP specifically asked about the effects of changing pots, which is why I did not discuss other ways to change tone or, in fact, whether or not it is worth doing.

As far as output goes, unless the basic principal of a voltage divider has changed, I do not have "the wrong concept in mind". Placing a 500K resistor (the pot at full volume) between the pickup and ground will produce a hotter signal than placing a 250K resistor in the same place in the circuit. Almost exactly 3dB hotter.

You're right about it not boosting output. Neither pot can boost output. The 250K attenuates more volume (and more treble) than a 500K will. The effect is subtractive, not additive.

The only way to get the actual, full output of the pickups is to bypass any volume or tone controls altogether and wire the pickups directly to the output jack.

96tbird · #12 11-21-2011, 11:51 AM

Agreed, I just didn't want op thinking it boosts output. To young ears your explanation may have confused. Just trying to clear that up, but I ain't no Shakespeare. Cheers.

Edit: I should have said: it lets more signal pass.

Lo-E · #13 11-21-2011, 11:53 AM

I dig.

Hell, if I were Shakespeare, I'd have a better job!

96tbird · #14 11-21-2011, 12:08 PM

Man, I just read end edited my post. I really did confuse it beyond sense! Duh!

JPMo · #15 11-22-2011, 07:27 AM

Thanks a lot guys, I'm open to anything that helps. I will try messing with my pickup height and see what happens. I'm sure that could use a bit of tweeking since I got the bass from GC online! *gasp* and its a lowly squier affinity lol