Carole Kaye swears by dialing volume on her pbass back by about a quarter.
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Does the volume pot position affect the timbre?
- Thread starter doran.dragic
- Start date
- Feb 5, 2013
- 1,686
- 2,281
- Disclosures
- Endorsing Artist: Used Fender Lead Sleds and Hartke cabs with bent grills
Yes, the volume control is also a tone control. This is a relatively easy thing to understand for those of us who design circuits. Your pickups are highly reactive - mostly inductive. The cable that you hook your bass to is highly reactive - entirely capacitive in the frequency range we're talking about. They resonate - at least when the volume control is full up. But the volume control is smack dab in the middle of the filter that's created circuit wise, so changing it changes the frequency response of the system. Dial it back, and the resonant peak that you get at full on the volume control is damped. At Mid volume (where the volume cotntrol is giving you half of the pickup's output), the impedance of the resistance in the circuit has its maximum effect - in that region, you not only are damping the resonant peak, in addition there's a rolloff from the resistance of the pot and the cable capacitance forming a low pass filter that doesn't exist at full volume.
Raising the pot value gives you more of that resonant peak (it's damped less) at full on the volume control. But when you dial it back, a higher value pot affects the frequency response even more - it's less of a volume control, and more of an (unintended) tone control.
That's the P bass situation. The VVT (jazz bass) circuit is worse - to give you two volume controls, the circuit shunts the pickups at less than full volume, which loses even more high frequencies.
All of this is because.....Leo designed his instruments in an era when they had tube amps that were noisy. To get the system to be as quiet as possible, he wanted to overwhelm the noise with signal. Doing that, He made a circuit that loads easily, and has all these tradeoffs. it was an OK decision in 1950, but today, we can do better.
I wire my basses differently. Being a guy who designs pro audio gear for a living, we do things differently. By using lower impedance pickups (most of the time, just doing a parallel connection will help tremendously), doing most of my capacitive loading on board the bass (before the volume control), and using lower value pots (with lower impedance pickups, this works fine), I get a resonant peak that doesn't get affected as much by the volume contlrol, and I avoid most of the filtering affects of the pot's resistance and the cable capacitance at mid volume positions. I can also, by choosing tcircuit vales carefully, get a higher peak on the resonance - essentially, what that means is your tone control now goes to....11 (maybe even 12).
None of this is the least bit controversial - I can find you a couple dozen folks at my company that would be completely capable of discussing what I'm talking about (once I explained the situation to them). The only thing that would surprise many of them would be that we've been making instruments with all these tradeoffs for so long, when the solutions to them are very well known (having existed for decades) in the pro audio world.
Raising the pot value gives you more of that resonant peak (it's damped less) at full on the volume control. But when you dial it back, a higher value pot affects the frequency response even more - it's less of a volume control, and more of an (unintended) tone control.
That's the P bass situation. The VVT (jazz bass) circuit is worse - to give you two volume controls, the circuit shunts the pickups at less than full volume, which loses even more high frequencies.
All of this is because.....Leo designed his instruments in an era when they had tube amps that were noisy. To get the system to be as quiet as possible, he wanted to overwhelm the noise with signal. Doing that, He made a circuit that loads easily, and has all these tradeoffs. it was an OK decision in 1950, but today, we can do better.
I wire my basses differently. Being a guy who designs pro audio gear for a living, we do things differently. By using lower impedance pickups (most of the time, just doing a parallel connection will help tremendously), doing most of my capacitive loading on board the bass (before the volume control), and using lower value pots (with lower impedance pickups, this works fine), I get a resonant peak that doesn't get affected as much by the volume contlrol, and I avoid most of the filtering affects of the pot's resistance and the cable capacitance at mid volume positions. I can also, by choosing tcircuit vales carefully, get a higher peak on the resonance - essentially, what that means is your tone control now goes to....11 (maybe even 12).
None of this is the least bit controversial - I can find you a couple dozen folks at my company that would be completely capable of discussing what I'm talking about (once I explained the situation to them). The only thing that would surprise many of them would be that we've been making instruments with all these tradeoffs for so long, when the solutions to them are very well known (having existed for decades) in the pro audio world.
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With a 50 cent capacitor (chosen for the same capabitance as the extra length of cable) wired inside his guitar, I could give him that same sound through a short cable, or into a wireless transmitter.
I posed a similar statement in a guitar-player's forum & they were having none of it, & insist it's not the same, LMAO!
Some players actually mimic Santana & have certain instrument cables for certain instruments or certain performances, it's maddening!
Some players actually mimic Santana & have certain instrument cables for certain instruments or certain performances, it's maddening!
The "volume" is just voltage level. An oscilloscope will show you the difference in the the positions as well as a frequency graph. The voltage level can make different frequencies sound louder or quieter for sure. Especially when you realize your ears do not hav a "Flat Response" and even if it did, your brain does not directly convey the waveform without its own "filtering" as well.
I wouldn't say all basses will, but my Fenders certainly get significantly brighter when turned up over 80% open.
I have a friend with a Jazz box guitar where he didn't want it to ever be completely wide open - he like the tone backed off just a touch. I added a resistor so when he was at "full volume" it really wasn't - essentially I modder his guitar so it went to....9. He was happy as a clam.
LOL! That's what I was referring to in post #14. I added a bypass switch around the resistor, too.
I understand that works for passive tone controls, too. Find your preferred tone that's not too bassy/muddy, measure applicable resistance, add resistor of ~equal value. Now at extreme end of tone pot, you hit your desired tone. Haven't tried it, but makes sense.
Yes. Guitar players who like tube amps have known this all along. And tone control affects volume. Even some thing as surgical as a recording desk channel strip, with full para and all kinds of shelving
So.... what I need to do is have a treble bleed, then a second tone knob which actually a volume knob without a treble bleed but with some sort of make-up gain... It's getting complex. Luckily I have the bits for a couple of the Passinwind preamps which allow me to sweep and modify resonant peaks, I hope. maybe I need to add an additional passive tone to that.
Can I add a negative resistor of 1 so mine goes to 11?
I see a market opportunity for what I described, then - a knob which is a blend type with a passive volume on one side and a gain control for an active pre on the other for make up gain. And some switches to add capacitors in. The switch can then be marked 'pure tone', 'Santana', etc. Dallas RangeMinimizer in a sense
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Before I understood the relationship of the volume pot to the overall tone, a great sound guy told me to dial back my volume pot a touch and it would make the bass sit better in the mix. It worked that night and I've used it pretty regularly since. Sometimes you want full volume and sometimes not. Depends on what you're looking for.
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