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EQ's, buffers...etc...i'm confused!

Discussion in 'Effects, Pedals, Strings & Things' started by trumpus, Jan 5, 2006.

  1. trumpus

    trumpus Supporting Member

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    So,

    I've been playing a while and using a ton of effects, and only recently have i picked up a line buffer (Doobtone microbuffer) and considered also getting an EQ pedal. Additionally, i recently purchased a Timmy, and noticed that it can be set as a unity gain buffer (which i have no idea what this means).

    Could someone explain the use and differences between buffers and EQ's?

    Can the timmy be used as a buffer/line driver?

    Also, where does the Zvex SHO fit into this equaion? I've noticed posts that liken this to the VHT plus a boost option?

    IM SO CONFUSED!!!

    I'm so confused!!! I have my Doobtone second in my line (after my RMC3), but i just don't know exactly what it is doing, and if it is placed in the correct position to optimize the benefits of it.

    If it helps, here's my setup:
    http://www.thegearpage.net/board/showpost.php?p=1068396&postcount=695

    The Timmy is now in place of the Small Stone, which has been moved to the FX loop board...

    How would you use an EQ in my rig (if you were me)? Where would you place the buffer? Do I need a separate buffer for my FX loop pedals (especially since these realistically have the longest cable runs - to and from the amp)

    Brian
     
  2. BrianB

    BrianB Member

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    I just wrote something about this so I'll quote myself... "buffer takes your passive – high impedance – guitar signal and converts it to an active – low impedance – signal at unity (same volume). What this does is allow you to run though all of your true bypass pedals and cables with less signal loss, high & low end loss and noise."

    Sure, the Timmy with gain/bass/treb all the way down acts well as a clean boost/line driver or buffer if you will; I'm not sure of the input or output impedance of the Timmy are so it might not necessarily be ideal as a buffer, but just by ear it does sound pretty clean.

    Similar to the way I described the Timmy, but in the SHO's case it has a very high input impedance, so it actually makes your guitar sound a little different (brighter, or sparkle).

    I like an EQ first in line. Some EQs might sound better near the end (Sea Blue EQ maybe, I think I've read people like it after drive), but others, like my Morning Dew work well first, extension of the guitar kinda thing. First is always best for a buffer so you can drive through all your pedals. Even before wahs as long as it doesn't have any weird affects. Oddly enough my MD Equalizer/Buffer does both of those things ;)

    The FX loop of your amp provides an active signal so you won't need one there. Hope this helps :)
     
  3. trumpus

    trumpus Supporting Member

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    Definately does! Thanks a bunch.

    An off topic question - i've had my eye on your Morning dew EQ (dig the antelope/MD ref by the way!). Any idea when this will be available again?

    Brian
     
  4. BrianB

    BrianB Member

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    Glad to help :) For the Dew I hope between the 15th and 21st of this month. They should look extra nice too :hiP
     
  5. StompBoxBlues

    StompBoxBlues Member

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    Just for anyone else reading that this still doesn't make sense for...a buffer if you use the classical analogy with electronics and water-plumbing...is like a way for transfer with the least signal loss.

    It would be like plumbing, but with some sections (input and output impedance) where the pipes are open, maybe going into a funnel. This is the best I can come up with...

    Think about a pipe like on a riverbank, open...water rushing out of it. If there is a pipe below it set to "catch" the water....if that pipe below is much smaller and has just an open pipe opening clearly a lot of spillage is going to happen...only a fraction of the water is going to get into the little pipe opening. Much better if you had a huge funnel and the receiving pipe was at LEAST big enough to handle the water coming from the source pipe. If it was bigger than the source pipe, no backup, no spillage, you have gotten all of the water (signal).


    This is a rough analogy, but this is what is meant by input impedance and output impedance.

    In electronics, to figure this stuff, they have what they call "approximations" and what you end up doing is simplifying. So for example a guitar into an amp, the amp is calculated down from the whole complexity to being represented by one resistor, the guitar signal another...these are the impedances and it ends up looking like a simple voltage divider. You want the most signal to come between the two representative resistors.

    Just for another way to look at it.
     
  6. theHoss

    theHoss Member

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    I run my MicroBuffer 2 first just because of pedal space, but I think I might try it after my RMC2? Anyways, I A/Bed my buffer when I got it, and it is a very apparent correcting the signal loss. It is my secret weapon. I really like mine as a buffer, and that leaves my Timmy to do anything it likes =)
     
  7. Kaiser

    Kaiser Member

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    I still don't understand, on another thread about this someone posted an tech article by Craig Anderto and still I don't really get it with your plumbing explanation, I'm an engineer too, so when electricals are talking I understand them just the techy stuff is hard for me, I don't know why I still don't get it. WOULD you mind trying to explain it one more time, maybe with apples and oranges, like I'm a five years old?

    Thank you very much in advanced!!
     
  8. dividedsky

    dividedsky Member

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    Morning Dew is an EQ and a Buffer...it's great.
     
  9. gregovertone

    gregovertone Member

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    where does one find the doobtone?
     
  10. StompBoxBlues

    StompBoxBlues Member

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    Okay...the water thing is pretty abstract. I can try more like what it really is, see if that helps.

    In any electronic circuit (and keep in mind I am not great at ascii art)
    where you have resistance in a circuit, to ground, the voltage drops before it hits ground.

    So, if I put 5 volts on a line going through a resistor, to ground I will measure 5 vols on the top of that resistor, and 0 volts on the bottom of the resistor.

    If I have 5 volts going first through one resistor, then through another it will be a voltage drop that is calculateable between them. IF they are the same value (say for arguments sake 500 ohms each) then the voltage drops will be equal. like this

    5 Volts

    0
    |
    | <------ measures 5 volts here...no resistance
    <
    >
    <
    |
    | <------ drop across the upper resistor, measures 2.5 volts
    | THIS IS ALSO THE POINT where the guitar signal
    < comes into the pedal, amp, etc. The lower resistor
    > is physiically inside the amp/pedal/whatever but it
    < is accurate to what is really happening.
    |
    | <------- drop across the second resistor (another 2.5 volts)
    | so this point measures 0 v, all the voltage is "used up"
    V

    Main thing to think about is that it always drops ALL the voltage, and it is a ratio of the resistances to each other. So if they are even, the point between the two resistors is always half whatever voltage is used.

    Here is the whole shebang now...let's say the lower resistor is almost no ohms...like 1 ohm, and the upper one is like 50000 ohms. I won't get into the calculations, but basically this would mean like 99.999% of the
    voltage will be dropped by the top resistor...leaving almost nothing at the point between the two...it would almost be ground. This is the point where the signal from the guitar gets into the amp or pedal. I know it seems weird, but it is because the electronics in the pedal are providing the resistance to ground which can be ruduced by calculation to represent that bottom resistor. This is what messes some folks up, they KNOW the voltage is ALL going into the pedal, but the pedal provides a resistance and path to ground. This is just like you can reduce (calculating) any complex system down to a simplified representation that is accurate!

    Anyway, in the example I gave (top resistor is very HIGH resistance (think impedance) and bottom is very low, you won't have much of the "signal" or remaining voltage after it is dropped by the top resistor.

    BUT...the opposite is also true. If that top resistor is very small in relation to the bottom...if that top one is 1 ohm, and the bottom 50000, THEN you will have the opposite. Which means measuring between the two, you will have ALMOST ALL of the 5 v still there. If you tap off of there into more circuitry (which we do...that is the signal that is getting amplified) then you keep almost all of the signal.

    The signal from the guitar is VERY low voltage (like 1 volt peak to peak or so). The main point to think about here is, the signal from the guitar is being tapped off between the point between the resistors. The guitar coils (in a passive guitar pickup) has an impedance that you can't do much about...I mean, it is what it is so unless you amplify it (active pickups) you have to have that as your deciding factor. So what you ideally want is to make the input to a pedal or amp, which is represented by the lower resistor but is many components, to be of such a high resistance IN COMPARISON with the upper resistance (the resistance from the pickup coils) that almost all of the signal is still available to be used.

    I hope that helps. It still works with water too though...

    Think of resistance as being pipe inside diameters. You got 500 gallons of water in a tank (same as 5 volts of electricity). BUT the 500 gallons is water pressure (voltage) which is the "potential" it has...where the actual flowing is the same as electrical current...meaning when something restricts the water flow you get back pressure...when the pipe is big enough to not offer any resistance you have water flow but no back pressure (no voltage)... going through a big pipe (the wire...no real resistance) but encountering a restricted pipe (resistor) and keep in mind "ground" could be a lake surface. Once you reach ground you still have water but it is not longer useable as it has fallen all the way (no more potential).

    So if you have really small restriction on top (resistance) and the lower one is hardly restricted at all, all the water is gathering at the top, a little is getting through but once it clears that top restriction, it meets no more real resistance and there is no built-up pressure. If you "tap off of" that point between the two restrictions, and if you are interested in back pressure (this is where it usually isn't so intuitive...signal information in electronics is the pressure differences...the change in voltage) you aren't going to have too much pressure to do much. If it is the other (the ideal way...much less restriction on top pipe piece, much more on the bottom) then most of the water will get pressure up again, at the tap point.

    Sorry...that is the best I can do this time. If this was just muddled, I can try again.

    Hope this helps little.
     
  11. StompBoxBlues

    StompBoxBlues Member

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    Sorry...that ascii drawing got screwed because the website takes away spaces. With the words in the way it is hard to see but mainly it looked like this


    5 volts

    o
    |
    |
    |
    \
    /
    \
    /
    |
    | <---- between the two resistors, tapp off point also
    |
    \
    /
    \
    /
    |
    | <----- 0 Volts
    |
    V


    Or

    5 volts

    o
    |
    |
    |
    \
    /
    \
    /
    |
    |---------------------> Signal onward, to be amplified
    |
    |
    \
    /
    \
    /
    |
    |
    |
    V ground
     
  12. StompBoxBlues

    StompBoxBlues Member

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    Just one last little thing. There is no one defined impedance that is nominal "high impedance", it is all relative to the input/output ratio.

    But the lower resistor in my examples is the one in the unit. Like on a digital recording machine, sometimes will have "Hi-Z inputs", (Z is the symbol for impedance) and that refers to the bottom resistance. It is calculated to be a much higher resistance (impedance) in relation to the input impedance (the top resistor in the schematic I drew).

    Also, impedance is very similar to resistance, but it is frequency dependant. It is like a resistor that changes its value depending on the frequency.
     
  13. nashvillesteve

    nashvillesteve Member

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    I have a question:

    My switching system (which blends 4 discrete signals into stereo outputs- including a couple loops, a relay and on/off switches for output to each amp for all four signals, echo, dirty, clean, looped) has stereo outputs. I am using a lot of effects and at the end of the chain and signals bouncing around. Since I'm going to be closer to my pedalboard than either of my amps, I had WOBO put in a buffered output to each amplifier with a level knob to adjust the output. So, hopefully, I can give the signal some unity as it heads to the amps' input sections- is that an improvement over just having as many as four signals just find their way to the amp? I should be able to adjust the volume a little from the pedalboard this way as well for each amp.

    I have a Crowther Hot Cake which I know works as a buffer (essentially a unity gain signal strength boost- correct?). Paul has recommended to me that it be the first in line in the effects order. However, I want to use a vintage style wah in the very front, which may not like the buffer (actually it sounds fine, but this wah is not modded/upgraded yet). Also, the signal splits between clean and dirty signals, which means that using it as a buffer/boost for both will put it necessarily before my Hellbaby and Hellbilly pedals. The Hellbilly has a germanium transistor in its front end, so it may not like the buffered or boosted signal before it. I will probably have a KR Doubler in front of that at some point, we'll see how it likes it. Or, I could follow through with my plan of going wah->Deluxe Memory Man (dry output)->FUTURE Red Witch Deluxe Moon Phaser->FUTURE Emma Discumbobulator, split by Deluxe Moon Phaser into:
    -Clean: AnalogMan Ross Clone
    -Dirty: FUTURE KR Doubler, Hellbilly, Hellbaby, Hotcake
    My plan here is to set each boost/fuzz/od box progressively cleaner cascading into each other. The octavia sound is going to be nastiest most likely, followed by the Hellbilly's fuzz/treble boost, into the Hellbaby's mid-range clean boost with option of adding some good "chunk" gain for the amp to chew on, into the HotCake set for clean boost.

    Should I move the Hot Cake earlier in the chain? Was it a good move to have buffered outputs for the stereo outs, since the aggregate strength of the 1-4 signals hitting the front end may vary depending on how many of the signals are engaged at any given time- so maybe the buffer will provide a greater consistency in signal strength?

    Do I really want to use the Hot Cake as a buffer? I wouldn't mind using it up earlier in the chain, especially for a clean boost for both clean and dirty lines. The only problem is that this is before the signal split, so the boost would be before pedals like the phaser, envelope filter tremolo, fuzz/boosters and compresssor. My main concern here is for how it affects the fuzz/boosters, filter and the compression effects. Wouldn't turning the Hotcake on to go from buffer to boost in this case be cancelled out by the fact that the compressor will adjust the boost to be a lower output level, making it ineffective?

    Should I also think about moving the compressor earlier in the chain, also before the split? I have been thinking that the "dirty" side would have greater contrast with the "clean" side if the clean side had a compressor and the dirty side had none, just boosts for a different dynamic scheme. Problem with the way I have it set up is that if I select the "phase/tremolo" output of the Deluxe Moon Phaser to be sent to my "clean" channel, the compressor is after it and will squash the dynamic differences. Also, the envelope filter is tentatively going to be placed immediately after the phase output so that the tremolo sounds from the DMP cause the filter to work at an increased rate, which may not benefit from then going straight into a compressor. I could switch off the compressor in this instance (the organ sounds get hit with some of the heaviest/most low-fi compression imaginable- the walco chord & note sustainer, so they'll survive), or I suppose I could lower the "sustain" setting. Possibly just keeping the attack delay control all the way up on the compressor would allow the gist of the modulated dynamics from the phaser/filter to come through OK and it will sound fine running them into the compressor.

    If I really need to, I am not opposed to getting a dual buffer pedal made by WOBO to simply buffer both clean and dirty signals earlier in the chains, although I suppose the answer I am looking for is that I did the right thing with the buffered outputs at the end of the chain.

    So, I'm looking for feedback on:
    a) buffer at end of chain = good/bad?
    b) hotcake as buffer (off) or just leave it on as a clean boost (on)
    c) phase/tremolo/filter effects into compressor (attack delay set high)?
    d) 1-4 signals->buffer->amp = better than 1-4 buffered signals-> amp?

    I just got my Furman SPB-8 today, which is awesome! It has a 10-jack stereo patch bay that I may be able to manipulate to my advantage, though I am thinking of just letting my Deluxe Memory Man and the future Deluxe Moon Phaser do the main splitting necessary before the switching system takes over the routing of the signals. I also don't have cables to hook everything up at the same time (might as well save up for the DMP first, since I need it to split the signal into stereo for clean/dirty lines). I want to get a 2 in/2 out Loooper.com box with one stomp and two LEDs to "swap" the phase/dry outputs of the DMP so I can use DMP->Discumbobulator sounds on clean and dirty signals (clean signal will be used for guitar and organ sounds, dirty probably only for guitar).

    Thanks!
     
  14. StompBoxBlues

    StompBoxBlues Member

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    Was that any help or was I too confusing there?
     
  15. 56_Special

    56_Special Member

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    I know this is an old thread, but I just wanted to thank StompBoxBlues for writing such a detailed and helpful response.

    Martin
     
  16. enickma

    enickma Member

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    I am so not an engineer ... uggh ! I must have read this 4 times and I'm totally lost. All I can go off of is my ear, and for whatever reason, I like my Barber Lauch pad as a buffer at the end of the chain. In the front of my chain it makes no disernable difference in tone, but the controls are way less responsive. For instance if I want to have more volume on my signal, I have to crank the volume and sensitivity knobs to hear a slight volume adjustment. At the end of the chain the responsiveness is dramatic. I can use it as an attenuator, or a signal boost. Completely transparant. Really cool pedal
     
  17. StompBoxBlues

    StompBoxBlues Member

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    You are really welcome! Thank you for letting me know it helped someone...it's hard to tell, but would be much easier to show if we were in the same room.

    Thanks for the response!
     
  18. Lucidology

    Lucidology Member

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    Some good info here ... Stompbox & others are on it ...
     

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