Are buffers used to clean up your sound?

Discussion in 'Effects, Pedals, Strings & Things' started by Jeebustime, Feb 16, 2012.

  1. Jeebustime

    Jeebustime Member

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    Tell me if im wrong, but I think buffers are just adding extra power to your chain. Does it just strengthen your singal so there's less "noise". I've been haveing a problem with some noise in my chain and im wondering if that will fix it. I'm currently running my epiphone sheritan into my tuner,wah,compressor,drive,envelope,phaser,and 2 delays. Only 2 of them are not true bypass. Is a buffer in this chain a good idea to imporve my tone? If not, what is?
     
  2. standingzero

    standingzero Member

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    I'd recommend doing a signal test.

    Plug straight in to the amp first, and listen closely to your signal. Then add one pedal after another and see how and when the noise starts coming in. It could be a pedal, could be a cable, could be the power supply, could be the grounding of electricity in a building (serious, my home buzzes crazy); could be a mixture of multiple factors.

    Start with that and also check your cables and input jacks of the pedals.


    Buffers change the impedence of your signal which in a nutshell helps with high end tone loss; so your tone does sound clearer; but not because there's "less noise" - but because more high end dynamics are coming through.

    good luck!
     
  3. Jeebustime

    Jeebustime Member

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    Thanks a lot for the imput. I'll check that out when I get the chance. I kinda have some suspision that it may be some poor cables.
     
  4. chervokas

    chervokas Member

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    Nope, a buffer won't help with noise (not to mention it sounds like, from what you say, you already have two buffers in your signal chain). All a buffer does is keep one part of the circuit from loading down another. So the guitar is loaded by the input impedance of the buffer, and the output impedance of the buffer drives the next device in line. That way none of the capacitance of the cable after the buffer will be loading the guitar, nor will the input impedance of any device after the buffer load the guitar. It doesn't strengthen the signal at all. In fact most buffers you'll come across in guitar signal chains are actually slightly less than unity gain, plus, of course, there's insertion loss, so you'll actually lose a tiny amount of signal.

    What kind of noise are you experiencing? You're probably just using a lot of gain and amplifying whatever noise there is in the system. If you were to further boost the signal it would probably make things noisier.
     
  5. Farbulous

    Farbulous Member

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    I live in an old house as well, and after upgrading all my cables (building them myself with soldered connections) the same buzz is still there. My power supply has isolated outputs so unless one of my pedals is the culprit, which I doubt because most are true bypass, the source of the buzz must be the socket in the wall. I've tried other sockets and it's always the same. Is there anything that can be done to get around this?
     
  6. chervokas

    chervokas Member

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    Well, does the buzz change or go away when you move or turn the guitar volume down? Is is present when you're plugged in straight into the amp with no pedals in line? Is it present in the amp when nothing is plugged into it? Do you have florescent lighting? Lighting on dimmers? Computers and other EMF radiating gear in the room? Are devices sharing the electrical line like refrigerators or condensers? First thing you need to do is isolate the source of the buzzing.
     
  7. Farbulous

    Farbulous Member

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    I'm having trouble isolating it, but I can tell you the following:

    The buzz does not change or go away when I move, but it does go away when I turn the amp volume down to zero.
    It is present when I am plugged straight into the amp with no pedals.
    It is present when nothing is plugged in, except with the volume off.
    I do not have fluorescent lighting, or lighting on dimmers on that floor, although there are dimmers in other parts of the house.
    I do have a computer plugged in (iMac) in the same room, but through a different socket.
    The amp is plugged directly into the wall and is only sharing the other socket with the power cable to my pedalboard.
     
  8. Farbulous

    Farbulous Member

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    And if it's not wired properly and I'm a renter? I'm not going to redo the wiring in this place. Are there any alternatives?
     
  9. chervokas

    chervokas Member

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    Ok, so you know the problem relates to the amp. Not the pedals or guitar or anything upstream of the amp. It could be a problem with line noise on the house ground -- you might be able to try an isolation transformer, although that's a relatively expensive solution. Does the amp have the same problem in locations outside your house? If so it could be an internal problem with the amp that could be anything from a bad tube, to a cracked solder joint, to leaky caps, etc. What kind of amp is it?

    BTW, make sure the lights on dimmers in the other part of the house are switched off, just to make sure and power down the computer, even unplug it from the wall. In fact, unplug everything from the circuit into which the amp is plugged for starters just to be sure -- not just the socket but the same 15A breaker circuit the amp is plugged into.
     
  10. spentron

    spentron Member

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    You only need 1 good socket (and a noise-free environment). Extension cord?

    But sounds like problem with amp itself.
     
  11. jnepo1

    jnepo1 Silver Supporting Member

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    Get a power conditioner and plug your board and amp into the conditioner. An Ebtech hum eliminator could help as well.
     
  12. Marrrty

    Marrrty Member

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    I count 3 non true bypass, DD7, Dynacomp and Carbon Copy. The buffer in the DD7 alone should rid you of the need for a dedicated buffer. Isolation test is in need i feel...
     
  13. Fred Farkus

    Fred Farkus Gold Supporting Member

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    Buffers drive current. That's it. They will provide all the benefits as well as disadvantages of driving more current. Originally they were used to drive a guitar signal through a long cable, like on a big stage for example. This kept the millivolt-level guitar signal from degrading as quickly for long cable runs. With a high impedance signal like a passive guitar pickup and the capacitance of a long shielded cable, eventually you will start hearing the high frequencies roll off and the sound gets duller. A buffer is typically used in that situation to restore clarity.

    OTOH, low impedance input effects like a fuzz face or rangemaster for example purposely load the passive guitar pickup in order to get the "smoothness" in their sound. They depend on loading that high impedance signal to sound "good". Put a buffer between a passive pickup and an effect like this and it will sound like a jar of bees. Some people may like this sound so no judgment there, but it is definitely not "smooth".

    Some people claim there are all kinds of mojotastic tonal benefits of buffers. Unless you have some sort of impedance mismatch or capacitive loss in (most likely a long) cable- you're probably not going to notice any radical difference with a buffer in the chain. Conversely, some claim buffers degrade sound quality. Again, much of this depends on your personal circumstances and how your rig is set up. In general, buffers are tools that are used to solve specific problems.

    If you are happy with your sound, whether you have buffers or not, don't worry about it. If you already have 2 or 3 buffers in your chain, adding another one is certainly not going to make any discernible difference- unless you feel you need it inserted somewhere in the chain you don't have it now for some particular specific reason. If you're just shooting in the dark, wondering if adding another one is going to give you any particular benefit- I can say with 99.9% certainty- NO.
     
  14. Farbulous

    Farbulous Member

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  15. Bufferz

    Bufferz Member

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    lets look at what’s going on when you don’t have any pedals. Your guitar is plugged directly into your amp with one cable. Assuming that the cable is a good quality ten or fifteen foot cable, your guitar is most likely sounding good and strong. If we were to change that cable to a thirty foot cable and then maybe fifty foot something begins to slowly kill your tone. It’s called capacitance. This is a fancy name for “drag on your signal”. The more cable that is introduced between your guitar and amp, the more drag you will have. It’s a scientific principle that signal/energy/current looses its juice when it travels a distance. Your guitar signal from your pickups is no exception.



    Now that we understand our signal can be affected with just the cable we use, lets look at what happens when we add those fancy stomp-boxes. Imagine that you plug into a true bypass pedal and then from that pedal into the amp. When you have that pedal in bypass position your signal is as if the pedal was completely invisible. The input jack is hard wired with the use of a switch directly to the output jack. The result is pretty good in this situation- assuming you have reasonable lengths of guitar cable on each end. Lets add another pedal and another, and another... With a large board that has six true bypass pedals and five patch cables to connect them together, you have around five extra feet of cable in your path! You also have twelve points at which your path enters into a jack and out to the next. Assuming that all the switches are high quality, you’re gonna hear frequency loss. The high end will slowly begin to fade and that sparkle that made you love your amp may not be there any more.

    - pulled from jhs website
     
  16. chervokas

    chervokas Member

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    This is not really an accurate description of how the capacitance of the cable affects guitar tone.

    Yes the capacitance of the cable between the a guitar with passive pickups and the first active device -- be it a buffer, switched-on pedal or amp -- affects guitar tone. But it has nothing to do with a "drag on the signal" or loosing current or "juice."

    An electric guitar is a passive device. So, one way of looking at it is that the inductance of the pickups, resistance of the pots, and capacitance of the cable together form a kind of circuit called a harmonic oscillator. This circuit will have a resonant peak at a certain frequency and a steep roll off of all frequencies above that resonant frequency.

    The guitar is a passive circuit involving and inductor (pickups), resistors (pots), and a capacitor (cable), and the resonance of that circuit defines a lot of the high harmonic timbre of what we're hearing. Its the same kind of circuit you can use to make a radio tuner.

    With a typical electric guitar circuit the RLC's peak is in the 2khz-4khz range, above the fundamental frequencies the guitar produces, in the range of the guitar's upper harmonics. So where that peak falls in the frequency spectrum plays a big role in the timbre of the system.

    Adding more capacitance to that circuit -- by using cables of greater capacitance per foot, or longer runs of cable, or both -- will tune the resonant frequency lower, resulting in warmer, more mid focused tone. Reducing the capacitance will tune the resonant frequency higher resulting in brighter, more open tone. Think of it more as a filter or an eq, not like a loss over distance, which at worst is utterly negligible in this context, especially with regard to tone.

    Now, there's another effect that is sometimes at work. The output impedance of the guitar and the capacitance of the cable together also form a low pass filter rolling off frequencies above a cut off point. That cutoff frequency will rarely come into play with the guitar's volume knob on "10" and reasonable lengths of average capacitance cable. You can use this calculator to see how it works. So for a guitar on "10" with a nominal output impedance of say 5K ohms (and remember impedance changes with the notes you play, or as you switch between pickups etc), and 35 feet of 33 pF/ft cable, the cut off point is still above 26khz -- above the range of human hearing and well out of the range of frequencies the electric guitar is putting out.

    So the low pass filter effects of cable aren't often a problem but resonant frequency tuning of the RLC circuit is always going on. Still, too much capacitance in line can bring this cutoff frequency down into the range of the guitar's output.

    We might use a buffer ahead of a chain of true bypass pedals to effectively reduce the capacitance in the RLC circuit -- only the capacitance of the cable between the guitar and the buffer is part of the circuit -- in essence tuning the resonant frequency of the system to a point where it sounds brighter than it would without the buffer and with all the true bypass pedals switched off in which case all the capacitance of all the cable between the guitar and amp would be part of the RLC circuit.

    Sure, there's loss at the connection points along the signal chain and I guess there's friction loss or something, but current loss is minor and not the principal thing affecting guitar tone when it comes to cable. It's RLC resonant frequency tuning, and maybe RC low pass filter effects that are in play.
     
    Last edited: Feb 17, 2012
  17. Bufferz

    Bufferz Member

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    thanks chervokas, great insights
     
  18. standingzero

    standingzero Member

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    This is become a really informative thread on many levels, AOK! Funny how something like this can start with a simple question about buzzing; I love this place.
     

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