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.1 cap is cutting most of volume.
- Thread starter bdplaid
- Start date
.1 is a pretty aggressive tone cap, it will low pass fairly low. Is your tone pot also wired correctly? Neither of the outside lugs should be connected directly to ground. Usually one outside lug is left empty and the other outside lug has the cap wired to it. The center lug, the one that connects to the wiper is the lug that usually connects to the hot signal.
Here is a little diagram for anyone else following the thread. Some people think better visually, than in written form, myself included.
Here is a little diagram for anyone else following the thread. Some people think better visually, than in written form, myself included.
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Yes, it’s a passive filter, all those treble frequencies not being heard when using a tone pot are being bled to the ground. So the more treble you bleed off the more signal just goes to the ground. Since the .1 cap is much more aggressive with how much top end is reduce the volume loss is much more noticeable. One trick with a bass with a neck and a bridge pickup is to have series/parallel switching. Both pickups in series will be much louder, then you can do a treble dump on the tone pot and have a very big thumpy, dub style tone. Simpler solution is don’t max out your volume when playing with tone wide open and then max volume when you dump the treble.
What is the small part with 2 lugs? The output jack? If so then why is the tone pot connected to it?
Never quite understood this . It is definitely apparent on my recently purchased Burns Bison , not sure of the cap value though . Solved by leaving the volume wide open and playing with a softer touch when necessary . On my fretless P bass with GZR pickup converted with a 0.1 tone cap , volume control works the same with tone pot open or closed .
Watching this thread with interest to see what folk say .....
Watching this thread with interest to see what folk say .....
Do you mean 0.1 uF or 100 nF? 0.1 mF is 100 uF which is HUGE.
Either way it may just roll off too much treble, maybe even cut into the midrange. Gibson uses 0.22uF on the EB-3 bridge mini-humbucker, and when you close it you do lose some volume and aggression.
Either way it may just roll off too much treble, maybe even cut into the midrange. Gibson uses 0.22uF on the EB-3 bridge mini-humbucker, and when you close it you do lose some volume and aggression.
Considering a 47 nF (0.047 uF) capacitor is pretty much industry standard to start with, you have exceeded the value of a usable cap for this particular application. I'd suggest changing the capacitor with a more reasonable value and see what this does for your volume loss.
A lot of folks use 100nF 0.1uF tone caps happily , myself included . In a simple P bass circuit with the right pickups they are perfectly usable with no volume loss and adjustment from sparkly to fat dub and everything in between .
"most of the volume" is key here. That points to a wiring or component issue.
I have .10uF caps in several Ps. Volume is not a problem.
I have .10uF caps in several Ps. Volume is not a problem.
typical J-Bass tone pot wiring...
This is the cheapest and easiest answer.
Passive tone circuits are very interactive so their behavior is affected by every other component in the circuit. Caps are so cheap that switching values until you find the one you like will only cost you a few dollars and some time.
For P-basses, Fender used .05uF most often but they also used .1uF and .02uF at various times for various model changes. There isn’t really a “right” answer. Try everything from .1 all the way down to .01 in increments and see which sounds best to you and interacts with the other controls in a way that doesn’t bother you.
FullumMusic
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- Oct 13, 2022
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It's a bit of two things causing this:
1- It's a LPF. The more you roll it off, the more of the signal it filters off from the top on down. The more signal it filters off, the less signal there is. Less signal can be (but isn't always) less volume. (This is fairly over-simplified, but the gist of what happens.)
2- Fletcher Munson curve. It's a LPF. And .1uF is fairly aggressive. The more you roll it off, the more of the highs and then mids and even low mids you're rolling off. Even if the measurable volume is the same, the apparent volume is lower.
i.e. You've filtered out the frequencies the human ear is attuned to hearing.
--
And that's just talking about rolling off the tone knob in isolation. If you also have your lows cut on you EQ, or you're running through a HPF that's set anywhere in the audible frequencies, you're essentially lowering the volume of the only frequencies your bass is making when you roll off your tone.
1- It's a LPF. The more you roll it off, the more of the signal it filters off from the top on down. The more signal it filters off, the less signal there is. Less signal can be (but isn't always) less volume. (This is fairly over-simplified, but the gist of what happens.)
2- Fletcher Munson curve. It's a LPF. And .1uF is fairly aggressive. The more you roll it off, the more of the highs and then mids and even low mids you're rolling off. Even if the measurable volume is the same, the apparent volume is lower.
i.e. You've filtered out the frequencies the human ear is attuned to hearing.
--
And that's just talking about rolling off the tone knob in isolation. If you also have your lows cut on you EQ, or you're running through a HPF that's set anywhere in the audible frequencies, you're essentially lowering the volume of the only frequencies your bass is making when you roll off your tone.
I won't say I'm knowledgeable about this, but I've replaced many a pot and cap in my time.
I usually use .047 caps, no problem there. I've played around with lower value caps, .022 and .033 so no problem there. Now I'm playing around with using caps that knock out a lot of the treble and midrange, and I have one setup that's interesting, that takes out every last bit of treble and a lot of midrange while keeping the volume, and I'm trying to replicate it. That system uses a .047 cap, but it might use 500K pots; I don't feel like disassembling it to see, but I'm 90% (or .90) sure they're 500K.
I dunno, this seems different than just a cap sending all its signal to ground, which was my first thought.
I usually use .047 caps, no problem there. I've played around with lower value caps, .022 and .033 so no problem there. Now I'm playing around with using caps that knock out a lot of the treble and midrange, and I have one setup that's interesting, that takes out every last bit of treble and a lot of midrange while keeping the volume, and I'm trying to replicate it. That system uses a .047 cap, but it might use 500K pots; I don't feel like disassembling it to see, but I'm 90% (or .90) sure they're 500K.
I dunno, this seems different than just a cap sending all its signal to ground, which was my first thought.
The bass got Munsoned!
I also experienced an apparent loss of volume with the big cap rolled all the way off in a P bass.
Not in my Strat and Jazzmaster, however.
.047uF doesn't cut volume but .1uF is necessary if one wants that old tubby tone.
I suppose a compressor or a tube amp with little headroom would level out the volume.
FullumMusic
Commercial User
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It's not sending ALL the signal, but enough of it across to spectrum to make a volume difference, and it's all in the frequency bands your ears are attuned to hearing, so even if the measured volume is the same (either with SPL meter or multimeter reading), it just sounds less loud because our ears/brain don't hear all frequencies equally.
Also, another thing at play might be the resonant peak at the cutoff frequency. Depending on the rest of the circuit's characteristics, there might be less of a resonant peak on your bass with the .1uF than on the .047uF cap. So when you roll off the .047 you're getting a slight bump at the cutoff frequency, whereas with the .1, there's no bump and it's only cutting. An electronics guru could explain the nitty-gritty behind what and why different resonant peaks happen.
If you're trying to replicate that other system, using the exact same pots & cap will probably get you close enough. Although, if the pickups are different, it probably won't be exact-exactly the same.
Well, that was easy to figure out. It wasn't a .1uF, but 1 uF. Pesky decimal points.
Back to our regularly scheduled programming...
Back to our regularly scheduled programming...
What kind of control circuit do you have? Is the .1uf cap new to the circuit? Here is why I'm asking - early Fenders had a cap between the volume and tone pot (in addition to the tone cap). It deliberately decreased the output volume when you rolled back the treble. This was to prevent amps (really more like early speaker technology) from "farting" due to the increased bass. The cap can be removed.
Jazz bass wiring. OP didn’t specify what kind of bass wiring. The hot of both volume pots on a J bass has a parallel connection to the input of the tone pot, which is also a parallel connection to the hot on the output jack.
If it was P bass wiring the center lug wiper input on the tone pot would be a parallel connection of the pup hot and the center wiper lug of the volume pot would go straight to the jack. For more clarity I should have just left that wire out and labeled the center wiper lug on the tone pot as hot input.
Here is VVT wiring for example.
Here is a VT with a few extras. I didn’t have a standard VT diagram on the ready.
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