Does the volume pot position affect the timbre?

[doran.dragic]

Hello everyone,

I own a beautiful Torzal bass that has Nordstrand Big Splits and Big Man pickups.

I love the way the bass sounds - it's very direct and responsive, but I was trying to get a pleasant old school roots reggae / dub sound out of the bass today and I just couldn't get the bass to sound right no matter which playing or muting technique I tried. Too much attack and too robust.

But after I took a short break the bass started to sounded much better, although a little quieter. Very rounded, very bassy and not as direct.

After checking my bass I noticed that the volume on my bass was only about 80% up.

I made a short recording of both volume pot positions which I matched the recordings for volume and the difference in sound was very obvious.

Could somebody explain me if this is the normal way for all pickups to behave? Will the change of the strength of the output signal not only change the volume but also the timbre? Or is there something else going on?

 

[BassDaddy77]

Interesting topic. I know on my G&L SB-1 with the split MFD pickup there was quite a change in timbre when backing the volume down from full. It was the only way to get into more of a traditional P bass sound. On that particular bass, with the volume knob wide open, it was a much more "in your face, hard edged" sound than I preferred.

 

[bholder]

Depends on the bass, but it does happen. Not consistently though, each bass (even of the same make/model) seems to have its own character or sensitivity. Part of figuring out your specific instrument.

 

[two fingers]

Interesting topic. I know on my G&L SB-1 with the split MFD pickup there was quite a change in timbre when backing the volume down from full. It was the only way to get into more of a traditional P bass sound. On that particular bass, with the volume knob wide open, it was a much more "in your face, hard edged" sound than I preferred.

I was going to mention MFD pickups as soon as I saw the thread title. My G&L L2000 sounds completely different with the volume backed down a bit. I've even thought about getting a clean boost pedal and using it to have "two different basses" when playing that bass.

 

[Killed_by_Death]

The volume knob actually acts like a low-pass filter when you roll the volume back a little:

That Resistor in the diagram is the Resistance you're putting between the pickup & the output as you roll back the volume.
Yes, there is inherent Capacitance in the circuit, even the instrument-cable has Capacitance.

AFAIK all instruments with passive controls will operate this way, but some Active instruments actually control volume at the preamp, some of Ibanez BTB models come to mind.

 

[FunkHead]

I think it's mostly how the signal hits the front end of your amplifier.

IME, if I have my active basses set flat, then the sound stays very similar as I adjust the volume.

If I have one frequency boosted, then as I adjust the volume then it has more of an affect on that frequency.

There is a certain amount of redundancy for every setting. Your bass has its tone shaping and volume and then your amp has its own set of adjustments. This is why you can get so wrapped up in knob tweaking. Then you find a perfect setting and that's when the magic happens. Switch basses and it can be lost and you have to start all over again.

P-basses are famous for being different at 90% volume Vs. Full on volume. That is some kind of filtering happening I believe.

 

[Nebadon2000]

Many believe with Passive Bass the type of Cable and length of cable can have 'filtering effect' also

 

[doran.dragic]

The volume knob actually acts like a low-pass filter when you roll the volume back a little:

Link Removed

That Resistor in the diagram is the Resistance you're putting between the pickup & the output as you roll back the volume.
Yes, there is inherent Capacitance in the circuit, even the instrument-cable has Capacitance.

AFAIK all instruments with passive controls will operate this way, but some Active instruments actually control volume at the preamp, some of Ibanez BTB models come to mind.

Brilliant, thank you for your explanation. Do you think that this would be achievable by installing a toggle switch so that the volume pot stays fully open all the time? That way I wouldn't have to worry about finding the sweet spot or being too loud if I accidentally hit the volume knob.

I think it's mostly how the signal hits the front end of your amplifier.

IME, if I have my active basses set flat, then the sound stays very similar as I adjust the volume.

If I have one frequency boosted, then as I adjust the volume then it has more of an affect on that frequency.

There is a certain amount of redundancy for every setting. Your bass has its tone shaping and volume and then your amp has its own set of adjustments. This is why you can get so wrapped up in knob tweaking. Then you find a perfect setting and that's when the magic happens. Switch basses and it can be lost and you have to start all over again.

P-basses are famous for being different at 90% volume Vs. Full on volume. That is some kind of filtering happening I believe.

Very interesting, I'll have to try this out. I have a HX Stomp which would make setting and storing different input levels very easy.

 

[lz4005]

Many believe with Passive Bass the type of Cable and length of cable can have 'filtering effect' also

That's not really an opinion. It's a measurable fact once the cable length gets over about 18 feet. Plus or minus a few feet depending on exactly how it's made.

 

[Nebadon2000]

That's not really an opinion. It's a measurable fact once the cable length gets over about 18 feet. Plus or minus a few feet depending on exactly how it's made.

I find it safer here on TB to express even 'The measurable' in a belief/opinion manor

 

[FunkHead]

I find it safer here on TB to express even 'The measurable' in a belief/opinion manor

I believed Buffered pedals can mitigate the problem. Or maybe it's non-Buffered?

 

[lz4005]

I believed Buffered pedals can mitigate the problem. Or maybe it's non-Buffered?

A buffer, either in a pedal or inside the bass, will mostly negate the effect of cable length, for cables after the buffer.

 

[Passinwind]

Could somebody explain me if this is the normal way for all pickups to behave? Will the change of the strength of the output signal not only change the volume but also the timbre? Or is there something else going on?

You might want to take a look at this for starters, as volume controls are often in parallel with the most usual passive tone control config and thus behave in a similar fashion:

Video Drop: Tone Cap Shootout (All About Tone Controls Parts 1 &2)

 

[fig]

My bass does the same thing, which I like. Usually keep it about 8 to 9 if I wanna take off some high end.

I think you could 'bake in' the sweet spot like this. Would require a resistor and simple switch.

Starting from 10 on volume, back up until you like it (let's say 8). Measure the resistance between the 10 end of the pot and the wiper arm (it's sitting at 8). Find a resistor at, or near, your measured resistance. Install resistor inline in the wire going to the 10 end of the pot.

Now, when you rotate volume to 10, you are at your preferred 'less trebly' setting. Adding an on-off switch around the resistor let's you select the resistor to be inline (less trebly at 10) or shorting around the resistor as if it wasn't there.

Sounds good on paper, anyway LOL. Will have to try that on mine. It's like the trick you can do on passive tone controls.

 

[Killed_by_Death]

the type of Cable and length of cable can have 'filtering effect'

Carlos Santana famously uses a really long instrument-cable, because he likes the high-end roll-off.

 

[nilorius]

I think a passive pickup volume pot up/down will not change the sounds timbre or tone.

 

[Killed_by_Death]

I think a passive pickup volume pot up/down will not change the sounds timbre or tone.

I vaguely remember 'discussing' a technical issue with you at least once before & to that I leave this response:

replace Science with Physics or Basic Electricity

I will concede that in a system with passive pickups & an active preamp, this filter has less of an impact, because the instrument-cable Capacitance is removed from the equation.

 

[JeezyMcNuggles]

Hello everyone,

I own a beautiful Torzal bass that has Nordstrand Big Splits and Big Man pickups.

I love the way the bass sounds - it's very direct and responsive, but I was trying to get a pleasant old school roots reggae / dub sound out of the bass today and I just couldn't get the bass to sound right no matter which playing or muting technique I tried. Too much attack and too robust.

But after I took a short break the bass started to sounded much better, although a little quieter. Very rounded, very bassy and not as direct.

After checking my bass I noticed that the volume on my bass was only about 80% up.

I made a short recording of both volume pot positions which I matched the recordings for volume and the difference in sound was very obvious.

Could somebody explain me if this is the normal way for all pickups to behave? Will the change of the strength of the output signal not only change the volume but also the timbre? Or is there something else going on?

The resonant peak changes as you turn the pot. It happens with all pots. Downside is keeping it where you like it without the ability to click into positions.

 

[Killed_by_Death]

That filter that I described above only changes the amplitude of the resonant peak, not the frequency.

This is an example of different Resistances & what they do the to the peak:

same graph, but when Capacitance is change:

the full article:

BuildYourGuitar.com :: The Secrets of Electric Guitar Pickups

 

[nilorius]

I vaguely remember 'discussing' a technical issue with you at least once before & to that I leave this response:

View attachment 4061365

replace Science with Physics or Basic Electricity

I will concede that in a system with passive pickups & an active preamp, this filter has less of an impact, because the instrument-cable Capacitance is removed from the equation.

Sorry, i meant a passive electronic, too.