Relationship volume and tone controls

Discussion in 'Technical Side of Things' started by lectric, Oct 23, 2020.

  1. GHook

    GHook Gretschie

    132
    Sep 3, 2010
    wnc
    I don't think it has to be a tube amp. But sound from a speaker into a room is way more organic than headphones. I admit digital amp reproduction is amazing tech but pumped thru a speaker cab is what allows you to control your guitars imput and allow for tone and texture. There is nothing wrong with learning to play and learning about tone at the same time.
     
  2. jarrodtaylor

    jarrodtaylor Gretschie

    394
    Mar 14, 2019
    Delray Beach, FL
    It’s hard to say exactly without seeing how your guitar is wired but maybe a primer on some of this will help.

    And if I have any of this wrong, someone please correct me.

    Start with a simple setup. 1 pickup and 1 volume pot. Let’s say the pot is a 500k (the usual for humbuckers). That means the resistance is 500k when the volume is all the way up on 10. Rolling down the volume pot lowers the volume by running part of the signal to ground (dividing the voltage). On a linear pot that means when the volume is on 5 you’re at 250k and half your signal is running to ground instead of to your amp.

    An audio taper pot will roll off at a non-linear rate, but that’s also how you hear volume changes so it works. There are lots of different tapers (even reverse tapers). We’ll stick with linear since it’s simpler to talk about.

    Not all frequencies roll off at the same rate (regardless of taper). Highs get cut off faster than lows. This has two important effects. First, rolling off your volume will darken your tone because it loses more highs than lows. And second, higher resistance lets more highs go to your amp. A 1Meg pot is brighter than a 500k pot which is brighter than a 250k pot. We’ll come back to this.

    Side note: Just as more lows can make your tone muddy, more highs can distort more. This has an effect on gain.

    Now let’s add a tone pot. Again we’ll go with a linear 500k. A tone pot is the same kind of pot as a volume pot, only it’s wired to divide frequencies instead of voltage. The value of the cap wired to the tone pot determines at which frequency it divides. When the tone pot is at 10 it’s not sending any signal to be divided. Roll to down to 5 and it’s sending half your signal through the cap. The cap splits the signal at a given frequency, sending the highs to ground and letting the lows keep going to your amp.

    Another side note: You can also wire a tone pot to send the lows to ground and let the highs through. This is a bass cut. It’s not common on guitars. G&L does it, so does Reverend. It’s good for focusing high gain and keeping it from getting muddy.

    So… Volume pots divide voltage, lowering your volume. Tone pots divide frequencies, controlling your highs (and sometimes mids depending on the cap value). Higher resistance lets more highs through (500k pots are brighter sounding that 250k pots).

    With modern wiring, your volume and tone pots are connected to the input lug of the volume pot. This means they’re wired in parallel so they work independently. Your volume controls your volume (remember that highs still roll off faster than lows) and your tone controls the highs of the entire signal.

    With 50’s wiring, your volume and tone pots are connected to the output lug of the volume pot. This means they’re wired in series (pickup -> volume pot -> tone pot). Now the volume and tone pots are interactive. There are a few big effects.

    First, the tone pot now only effects the amount of signal coming out of the volume pot. So as you roll down the volume the tone pot will make less of a difference.

    Second, the resistance is now the combination of both the volume and tone pots in series. Both pots at 10 will have a resistance of 1Meg. Because higher resistance lets more highs out to your amp, it’ll sound brighter. Rolling the volume to 5 is now 750k instead of 250k. And since it’s still a volume pot it’s still dividing the voltage in half. Half the voltage (volume) but a higher resistance (more highs). That’s why 50s wiring keeps your highs as you lower the volume. This works the other way around as well, where lowering your tone pot will change your volume along with dividing frequencies and cuttings highs. That’s what people mean when they say it’s more interactive.

    If you go with modern wiring and still want to keep more highs you could add a treble bleed. It’s a cap wired to your volume pot that cuts lows. Less lows makes it seems like you aren’t losing highs so fast.

    And all that's before the signal leaves the guitar!

    When I read this earlier I didn't catch that a Boss GT-10 isn't an amp. Yes, less watts will overdrive faster. Solid state amps and tube amps handle this in very different ways. Most headphone options don't work very well, unfortunately.

    Check out a Yamaha THR10C amp. It's a lunchbox size combo amp that simulates a few classic tube amps and has some useful built-in effects. You won't need any pedals, you can play it at bedroom volumes, it has a nice sounding headphone out, and a second input so you can plug in your phone (or stereo or iPod or whatever) and play along with a song.
     
  3. michelb

    michelb Gretschie

    Age:
    30
    423
    Mar 27, 2020
    Belgium
    I don't know how well the boss simulates effects, but I'd say you can test it by selecting an overdrive pedal, not a distortion pedal and turning de gain low to about a third or something and compensating with the pedal volume. That way the pedal should barely overdrive the signal. Then if you play your guitar soft I should sound clean-ish and when you play hard it should overdrive.

    The idea of selecting the output wattage is indeed to dial the amp like you want it and then controlling the output wattage to lower the volume. That way the amp can do it's thing and come to live, it'll just lower the output to the speaker so you don't blow out your windows and eardrums.
     
    Last edited: Oct 26, 2020
  4. lectric

    lectric Electromatic

    51
    Apr 7, 2020
    Belgium
    First of all, thanks for the helpful post! Regarding the way my guitar is wired, I have had it wired as the guitar in the first video I posted.

    I follow you on the linear vs audio pots, that's why I assumed my volume pots would've been audio pots, but when I asked to be certain, they said they were linear pots, as these are mosty used for volume pots, and the original volume pots were also linear pots. I understand that my tone control has influence on the volume in the 50's wiring, but I still think it's strange that my tone control has more influence on the gain than my volume control... At the moment playing hard with gain is no problem, playing soft without gain is only possible with the tone know all the way down, from the moment I turn the tone knob to get some high frequencies, the sound distorts.

    No, correct, the Boss GT-10 is an older flagship multi-effect pedal. Since an amp isn't an option at the moment, I figured that if I bought that unit, I had all I could wish for for now ánd for the future. Amp simulations are in the unit, and all possible effects I can think of, so if one day I buy an amp, I don't have to wory about pedals/effects either and in the meantime I can play with headphones. So I figured it 'd be even better than an Boss Katana amp...
     
  5. lectric

    lectric Electromatic

    51
    Apr 7, 2020
    Belgium
    I tried it with just an amp simulation, no pedals involved and with just gain on the amp sim and still had the same results... no clean sound if I turn up the tone knob.

    Regarding wattage: OK, thanks for confirming. So I assume the BluGuitar Amp 1 is not the best solution for home practice at low levels?
     
  6. RomanS

    RomanS Gretschie

    404
    May 26, 2010
    Vienna, Austria
    For home practice at low volume (apartment level, late at night), the Yamaha THR series is really one of the best options out there.
    No experience with the BluGuitar on my part.
     
  7. lectric

    lectric Electromatic

    51
    Apr 7, 2020
    Belgium
    I have the idea to at some point in the future buy some studio monitors. I guess hooking these up to my GT-10 would be good (or maybe even better) too, no? Or am I missing something?
     
  8. GHook

    GHook Gretschie

    132
    Sep 3, 2010
    wnc
    They would be better than no amp. You could probably pick up a starter amp like this Orange, for about 100.00 bucks. Decent low end monitor speakers will run about $100-150 each. Screenshot_20201025-132743_copy_720x1011.png
     
  9. jarrodtaylor

    jarrodtaylor Gretschie

    394
    Mar 14, 2019
    Delray Beach, FL
    The part that’s missing is the amp itself. Monitors would work better than headphones.

    Guitar effects (whether they’re pedals or a big digital effects board) are usually designed to work with a guitar amp. Guitar amps do more than just make your guitar louder. The preamp and power amp sections both do a lot for your tone and the speakers are designed to work well with the frequency range of a guitar. An amp is just as much part of the tone as the guitar and the pedals.
     
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  10. michelb

    michelb Gretschie

    Age:
    30
    423
    Mar 27, 2020
    Belgium
    You'll indeed not be able to get around this. I'd get a modelling amp and figure out what sound you want, to eventually buy a proper amp.

    You won't be able to cut the amp out of the equation, unless you use a Strymon iridium or actual software like amplitube. But that still won't give you the sensation of an actual amp pushing air.
     
  11. lectric

    lectric Electromatic

    51
    Apr 7, 2020
    Belgium
    @GHook, thanks for suggesting that Orange Amp.
    @jarrodtaylor: the part is missing the amp itself you say. If you mean "guitaramp", than yes, but I'm talking about active monitors.

    I might perhaps further elaborate on the monitor-thing a bit further. I am actually a drummer, taking up guitar. As said, my current situation doesn't allow me speakers and/or too much noise, so at home I'm playing an electronic drumkit with headphones. So the idea is to - when my situation has changed - to buy active studio monitors (and probably a subwoofer), so I can amplify my e-drums. In a far past, I took pianolessons that I had to quit after a year. Also, at some point in time, I'll probably be taking that up again too. Basically, the idea is to buy some studio monitors at some point, connect them too a mixing board, and have the e-piano, the e-drums and the guitar all going through the monitors. Hence the Boss GT-10 that has all these amp models in it as well.

    Jarrodtaylor, dumb question perhaps, but the preamp section of a guitar amp, what exactly is that? Obviously, the power amp part is the amp itself, the part that amplifies... The preamp section, that is? The different channels and the EQ-section? I know an amp also colours the sound, but that's one of the reasons why I'd opt for decent (!) studio monitors, so whether I play drums or guitar, I can shape the sound in my drum module/GT-10 and have that sound through my monitors, without the monitors changing that sound.

    @michelb: the GT-10 has dedicated amp models in it, you can check them here: https://www.manualslib.com/manual/497961/Boss-Gt-10.html?page=98 That Strymon Iridium indeed won't give me the sensation of pushing air, just like my GT-10. But I assume studio monitors will push air the same way a small guitaramp will, or even a normal guitaramp when there's a sub involved, right?

    For the ones interested in the GT-10, here are some great (IMHO) user clips:
    - David Gilmour:
    - Steve Vai tone:
    - Gary Moore tone:
    - Slash tone:
    - Eddy Van Halen tone:
    - Yngwie Malmsteen tone: https://www.youtube.com/watch?v=l5j5La4zDRY;
    - John Petrucci tone: https://www.youtube.com/watch?v=7bL3m9W22hg;
    - The Edge tone: https://www.youtube.com/watch?v=ML0_8olTtQI.

    IMHO, these sound clips are spot on, or in case not spot on, véry alike... So I think, sound shaping wise, that GT-10 is all/more than I need.
     
  12. jarrodtaylor

    jarrodtaylor Gretschie

    394
    Mar 14, 2019
    Delray Beach, FL
    If you have other uses for monitors, then by all means get some. It’s a useful tool.

    These two are related. What comes out of the speakers is tone that’s essentially already been mixed and produced. It’s like a 2D representation of a 3D sound, if that makes sense. Or playing a racing game through a TV instead of driving a car. No matter how good the simulation gets, it’s only covering the superficial sensations. And I say that as someone who owns an Iridium and thinks they did a very good job with it.

    Bringing this back around to your original questions, what it comes down to is that you can’t expect your guitar to interact with your GT-10 the same way it does with pedals and an amp. If it did, that kind of technology would’ve taken the guitar world by storm many years ago. Bring your guitar to a music shop next time you get a chance and plug it into an overdrive pedal and an amp. The controls will most likely work as you originally expected.

    For more info on preamps (again, they’re just part of a bigger equation) and on playing direct without an amp, I refer you to That Pedal Show. If you’re interested in this stuff and haven’t watched these guys, they have a *lot* of great videos.



     
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  13. GHook

    GHook Gretschie

    132
    Sep 3, 2010
    wnc
    You sound secure in your decisions to proceed. I'd say with all the excellent answers on this thread your decision will be at the very least, informed. Have fun as you proceed with guitar. I started out life as a bass player 50+ years ago. I love the idea you never arrive at your musical destination....fills in huge swaths of available time.
     
  14. GHook

    GHook Gretschie

    132
    Sep 3, 2010
    wnc
    What an articulate explanation as too voltage and freq. I never stop learning, thanks!. I owned a G&L Legacy and loved the 3D tone circuit set up,great feature.
     
  15. jarrodtaylor

    jarrodtaylor Gretschie

    394
    Mar 14, 2019
    Delray Beach, FL
    Thanks. I like writing that kind of thing because it forces me to clarify what’s in my head.

    If you want to add a G&L style bass cut to another guitar, it’s actually really easy. It’s the same principle as a regular tone control, only it blocks the other side of the frequency split so the lows don’t get through. Get a .0022 cap so it splits the frequency at the low end (and won’t filter mods) and order a 1meg reverse audio taper pot from G&L’s online store. You can Google the wiring diagram and it’s even simpler than a normal tone pot wiring.
     
  16. GHook

    GHook Gretschie

    132
    Sep 3, 2010
    wnc
    Thanks @Jarrod. I am way past wiring days. Just don't have the dexterity, but the knowledge is great. So much tone on my Corvette, LP and Fretless Ibanez 4 string Bass ( Portamento) come from minute tweaks of each pups volume knob and tone knob. On the Fretless I can even blend in Piezzo. The pups tone circuit is active on the bass although I would not choose them on any 6 string I own. A very under rated home based amp is Fenders Mustang GT40. It is perfect for apt playing as it can handle bass also, at low volume / gain of course.
     
  17. lectric

    lectric Electromatic

    51
    Apr 7, 2020
    Belgium
    Jarrod, thanks a lot for these videos, they were very informative. Maybe a stupid question, but still... you said I can't expect my guitar to interact with my GT-10 the same way it does with pedals and an amp. I assume that a guitar then won't react the same way with a modelling amp the same way it does with pedals and an amp, right? Since essentially, the GT-10 (or whatever multi-effects pedal with amp modelling) is in fact a modelling amp without the amp part...

    So basically, in case I 'd like to use studio monitors/powered speaker and want my guitar to act like with a guitar amplifier, you need something like that Kingsley Maiden, or AMT SS-20 (https://www.thomann.de/be/amt_ss20.htm). Thanks!
     
  18. jarrodtaylor

    jarrodtaylor Gretschie

    394
    Mar 14, 2019
    Delray Beach, FL
    I could go on for days about modeling amps, but the short story is this. The ones that try to model an already produced sound, like you’d hear on a record, tend not to work well. Some of the new ones that model just what an amp does tend to work a lot better. The Yamaha THR series and the Fender Tone Master come to mind as good ones.

    I don’t know enough about the GT-10 to say definitively one way or another. It could be the input impedance is off, your EQ could be off, the headphone out could be bad (most guitar gear involving headphones doesn’t sound very good).

    Maybe? You’d have to try it and see. But they aren’t cheap and for the same money I think you’ll be better off with a Yamaha THR or The Amp from Milkman Sound. You could play either through headphones or studio monitors. The THR has its own speakers that are bedroom level quiet. The Milkman Amp is actually a tube preamp with a class D power amp, so if you wanted to play loud sometime you could easily plug it into a guitar cab as well.

    Or for a little more a get Fender Tone Master and not have to think about any of this stuff anymore. Plus those come in blonde now.

    And a little meta rant: It seems like every time topics like this come up, the real solution is “get a good guitar, plug it into a 50 or 100 watt tube amp, and crank it up until the speakers move enough air to make your jeans flap in the wind and your ribs vibrate”. Which is of course the correct answer.
     
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  19. lectric

    lectric Electromatic

    51
    Apr 7, 2020
    Belgium
  20. lectric

    lectric Electromatic

    51
    Apr 7, 2020
    Belgium
    For the people interested... as jarrodtaylor already (correctly) - and I already confirmed as well - assumed, my volume pots are linear, that's indeed why I don't have the same result in going from gain to clean tone by changing the volume like in this video: . In the following video you can see and hear the difference between linear and audio taper volume pots, both in a clean and a gain setting: .
     
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