Anyone want to explain true bypass pedals, buffers etc?

Discussion in 'Effects, Pedals, Strings & Things' started by Wibcs39, Dec 4, 2013.

  1. Wibcs39

    Wibcs39 Member

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    I am fairly new around here and just trying to understand some things that I see mentioned. I have always sort of thought true bypass=good. But I am seeing people mention how too many true bypass pedals need a buffer, etc...and I don't understand that whole thing. I currently use a boss tuner into 5 true bypass pedals. So, what is the boss TU2 doing in this scenario as a buffer? And what is the basic reason behind a bunch of true bypass pedals causing problems with tone? Thanks, and sorry for creating a thread that has probably already happened many times!
     
  2. justnick

    justnick Supporting Member - Gold

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  3. justnick

    justnick Supporting Member - Gold

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    And, in case you don't want to watch the video, a very short answer.

    Instrument cables have an electrical characteristic called capacitance.
    In combination with the characteristics of passive pickups, this capacitance can make things sound darker once the cable lengths get beyond around 15-20 feet (depends on cable, pickups etc.)
    True bypass pedals are basically acting like additional cable when they are off (just a few inches each+patch cables etc.). So it's not the pedals, just the length of conductor/cable.
    When you put a buffer in line, or any powered effect that is switched on, it electrically isolates your pickups from the capacitance of subsequent cabling and, if the first cable isn't too long, prevents high end roll off.
     
  4. Belmont

    Belmont Member

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    think of your guitar cable like a garden hose.
    think of each true bypass pedal like a valve that allows most of the water through but restricts a tiny bit.
    add up 5 of these and the water pressure coming out the end of the hose isn't as strong as it was.
    putting a buffer first in line is like taking the water tap and turning it up so that the water pressure is strong again.
    a buffer is like a littler booster preamp.
    lol, hope that helps.
     
  5. justnick

    justnick Supporting Member - Gold

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    This is actually not what happens at all. No offense, I know you are trying to be helpful, but there's a lot of confusion around this issue and a lot of it is due to this paradigm. Here's another video (I know, me with the damn videos!) This one explains why our signal "chain" is not like a hose at all and why understanding it differently will make a lot of things about guitar electronics easier to understand:



    The problem has nothing to do with the signal getting "weaker." It's to do with the components in the circuit, including the cable, tuning the circuit's frequency response. We actually don't care much about how much current is flowing. Consider the fact your pickups have 4-10,000 ohms of resistance and you'll see that the issue is not a restriction of current flow here.
     
  6. JParry335

    JParry335 Member

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    Just Nick,
    Great videos! Very informative.
    Thanks for sharing your knowledge and experience.
     
  7. chervokas

    chervokas Member

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    I'm sure Nick's vids will tell you all you need to know on this score.

    Basically, the total amount of cable capacitance between a guitar with passive pickups and the first switched-on device (be it a buffer, pedal or amp), will have an impact on the frequency response of your system. More capacitance will tend to make the frequency balance warmer, less capacitance will tend to make it brighter (especially with single coil pickups).

    If you have a 10-foot pedal to your pedal board, five true bypass pedals connected with 1-foot cables, and a 20-foot cable from pedalboard to amp, that's 34 total feet of cable.

    Say you're using cable with a capacitance of 30 pF/ft and all the true bypass pedals are switched off. That's 1020 pF of capacitance connected between the guitar and amp (34 ft X 30 pF), because with true bypass pedals when the pedal is switched off the signal is just passed straight from pedal input to pedal output.

    A buffer is a circuit that keeps everything after it from loading what's in front of it. The TU2 is a buffered bypass pedal, that means even when the pedal is switched off the buffer circuitry is still active. If you stick that in the front of your pedalboard in the scenario above, now only the capacitance of that first 10 feet of cable between the guitar and the TU2's input buffer (300 pF of total capacitance) is affecting the guitar's frequency response and the frequency balance will be brighter than before when 1020 pF of capacitance was involved. That's what the TU2's buffer is doing in this scenario, reducing the amount of cable capacitance loading the guitar when all your effects are switched off.
     
  8. rancid.keone

    rancid.keone Member

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    I read the heading on this thread thinking (this subject again!!)

    Thumbs up for the videos though...
     
  9. Wibcs39

    Wibcs39 Member

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    Thanks for the helpful and informative responses! I am gonna watch those videos later tonight. I have been using pedals in various combinations for close to ten years and never really learned any of this! Luckily, I have no desire or intention to ever use more than a handful of pedals (when the gig/situation allows, I use basically no effects) but even with my current setup, I feel i lose some of the warmth or depth of the tone and it can be frustrating.
     
  10. Vishnu

    Vishnu Member

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    I will guarantee you one thing........I'll bet Hendrix never gave such issues a 2nd thought........"Hmmm, where will I put this wah in the signal chain?"

    play about with things and if it sounds good to YOU........you have hit a home run
     
  11. walkerrn

    walkerrn Member

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    Translation: Just do whatever, or actually read, watch and learn from people like Just Nick and come away a smarter person.

    Alternatively, we should all be Hendrix.
     
  12. chervokas

    chervokas Member

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    Maybe -- although he had people around him, engineers and the like, who did think precise about those questions -- guys like Roger Mayer who modded gear for him and obviously in the studio Eddie Kramer. And Hendrix still had lots of equipment problems on the road, especially with radio breakthrough and noise. Just because someone, as great as he was, did something 45 years agodoesn't mean doing it the same way today is still a best practice, especially when it comes to tech.
     
  13. Loop-Master

    Loop-Master Member

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  14. drbob1

    drbob1 Silver Supporting Member

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    Actually, whether it was Mayer or Hendrix who set up his signal chain, he made some inspired choices. Try plugging a stratocaster straight into a Sunn amp with 6550s and JBL speakers. The treble will take your head off. Now add a treble booster? No fun at all.

    Now take the same guitar, run it thru a cheap, 20' coily*cord and 3 or 4 unbuffered (and not true bypass) pedals, all of which suck some treble, and see how much more pleasing the guitar sounds.

    It's not that buffers are better, it's that you want to be able to predict how your guitar is going to sound. And it CAN be a problem if you've got a bunch of pedals sucking treble, then you turn on the first pedal and all of a sudden all that treble comes flooding back-if that first pedal doesn't have a tone control life can be difficult!
     
  15. 7 Electrons

    7 Electrons Member

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    I wrote this article for Premier Guitar last year. It may help shed some light on the subject.
    http://www.premierguitar.com/articles/The_Truest_Bypass

    -terry
     

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