Some Informal Effects Chain Advice

How should I set up my system if Im using a number of effects boxes? ( This could also be subtitled: An argument for buffering as True Bypass is not always desirable in a system) Most players rigs are a mix-and-match affair, which encourages individual personality in players sounds, as opposed to everyone using the same box and being homogenized. So with that in mind, the following advice is to keep musicians generally - and guitar players in particular - experimenting with their beloved (mostly analogue?!) stomp boxes, new and old, yet avoiding the pitfalls of such anapproach. I should say right away that if there's any real wisdom here, a lot of it is what I learned from reading an article on Pete Cornish (still the main man for Guitar Effects systems) and having chatted with him when I met him many years ago. The rest is my spin on it.

Disclaimer: What follows is my own summary of what I believe constitutes a good approach and system of connecting guitar effects, as we know them. You are of course, free to disagree! It assumes that even in the 21st century, most electric guitar players (being in some respects a bit conservative technically, though not always without good reason) have not yet done what many bassists have been doing for years and often still use passive, high-impedance pickups rather than active ones and tend not to use on-board guitar (active) pre-amps. I don't want to go down the "self-appointed guru" route and be drawn into endless discussions on this subject so please, not too many questions!! I have put this out merely to help, rather than hinder and just hope it will be a useful resource to some, perhaps even most of you guitar players and muso's with "gear".

A (fair) bit of technical, theoretical stuff The general requirements for loading a guitar's (passive) pickup are: a high impedance load of typically at least 1 Meg-ohm and ideally no more than a few tens of picoFarads of capacitance. The latter is usually more than adequately provided by the interconnecting cable (and then some - a standard 12 foot guitar cable may have several hundreds of picoFarads of capacitance across its terminals, especially if its a poor quality one; this capacitance causes irrecoverable treble loss when it gets too excessive).

A guitar amp input provides the right kind of load, and thus presents the instruments pickup with an optimum, unchanging high-impedance, ensuring the best possible sound quality and frequency response. However, all of this can go out of the window when using a very long cable (this in practice means two standard guitar cable lengths or more), and things can get problematic with the addition of even a small number of effects devices added between instrument and amp, unless the following advice is understood and applied: The ideal requirement for an FX pedal is that the impedance of the input is high (like a guitar amps input) and the output impedance low, typically just a few kilohms (like a guitar pickup) or even less in practice. This much does apply to pedals that use electronic buffer-bypass switching, such as the classic Boss and Ibanez pedals designed in the 1980s.

Since that era, pedal systems have come a long way, yet the latter-day argument for "True Bypass" has caused much confusion, especially when thrown into the equation of a multiple effects set-up. True Bypass means simply a piece of wire in bypass, so the effect circuitry is no longer in the signal chain, the idea being that this is going to improve the sound in bypass. Well, it might sound natural/uncoloured if you have one box and two short cables in your bedroom or studio, but it doesnt hold any real advantages if you are on a stage with say, half a dozen or more pedals and a long cable

run. The reason being that in all but the simplest set-ups, the act of switching the effect in question "in or out" will change the driving impedance of the system at that point, in relation to the various cable runs and their capacitances, resulting in a complex state of affairs regarding signal level, noise, quality and equalization as different effect combinations are selected. If all boxes are true bypass and selected Off, the guitar's pickup may end up driving the entire cable run, and will certainly struggle to do so without noticeable losses. However, placing a single buffer/line driver at the start of that chain would transform it into an ideal rig.. The system performance is always determined by the output impedance of the last active (here, meaning "signal generating") device in the chain before the cable that goes to the amp input (assuming Guitar at start, Amp at finish!) and its ability to drive subsequent runs of (lossy) cable downstream, whose length effectively alters as subsequent effects are switched in and out of the chain, owing to their differing impedance and bypass modes.

Also, there is no standard specification for the impedances of pedals, especially the older or ironically, some of the more recent ones, so it is feasible that an effect like this can have a very low input impedance of just a few kilohms, and other effects may have an output impedance of tens of kilohms, resulting in signal attenuation when such a pair are connected together (The venerable Fuzz Face TM and its modern derivatives being a classic example). BTW: Dinosaural pedals are all designed to have ideal impedances. The only way to totally avoid this problem and many similar scenarios is to have a buffer between each pedal. In practice this is not the best thing for the bypass sound as the signal is then going through a lot of unnecessary silicon a 1980s scenario that provoked the True Bypass backlash, and up to point, quite rightly so. Cascaded buffer circuitry gets noisy. So, buffering between each pedal can be overkill, and would outweigh any advantages of good impedance-matching, especially with many pedals in a line.

What's best to do? The best compromise is to use a single high-quality buffer or line driver placed directly AFTER the guitar cable, but BEFORE the first effect pedal. Having one other buffer at the end of the chain before the long cable run going to the amp would also be advantageous - desirable even - but is less crucial and can probably be safely ignored in a simpler system and with a relatively short cable run to the amp. Buffering just once after the guitar's cable (which should be the best quality cable you have - see later) will avoid many pitfalls, as the guitar pickup sees its optimum load at all times, and the controls on the instrument will work at their best, and consistently so. Maximum power transfer is thereby maintained in all conditions and the transient performance will always be good in bypass: surely, the bypass sound should be as good as any effect sound? Loss of signal quality rendered by the subsequent cable runs and their changing capacitances and susceptibility to interference and handling noise, etc will no longer be a major issue, because the cables capacitance will not significantly load the now-constant, low driving impedance. Because buffering provides a very low output impedance, the resulting sound, particularly in bypasswill be far clearer in the top end and generally gutsier than without. Ironically, this will be closest to the sound of your guitar plugged straight into your amp with a short cable than if you used true bypass on all your boxes and switched them all off, owing to the considerable signal and quality losses that would otherwise occur in practice.

Cables etc.Use a medium-length cable between your guitar and the buffer, and ensure that THIS one is a low-loss, high-quality, low-capacitance, low-noise OFC (Oxygen Free Copper) type (ideally with a semiconducting sheath for low handling noise) and uses top quality connector (s) such as Neutrik or Switchcraft. This is very important, as this single cable will now be the weakest link in your system, and will therefore determine the best available sound quality from your instrument.

Subsequent cabling will be less important in terms of capacitance losses and noise ingress, but its a good idea to make sure that the quality of these is at least pretty good and again, that the connectors are of high-quality. Keep your connectors free from dirt and grease by occasionally wiping them with a dry, lint-free cloth, such as Scotchbrite. Gold-plated connectors are really overkill in these situations, as the plating soon wears off with movement - its only a couple of microns thick! Soldered cables are probably better than unsoldered ones, purely from the point of view of mechanical reliability and low grounding resistance. Also, avoid treading on or stressing the cables, as this can (and eventually will) cause signal losses due to capacitance increasing between the core, dielectric and shield as they become deformed.

Effects

If you use a compressor, the forthcoming Dinosaural model would make an excellent start to the signal chain, as it uses a high quality low-noise buffer/line driver in bypass. Plug your instrument directly into this and whether selected on or off, it will have a buffered, low-impedance output - ideal to provide you with a trouble-free rig, as regards buffering. It doesnt matter then whether your other effects are electronic/buffered or true bypass, semi-true bypass, heart bypass, etc. A bit of a life-saver in all respects!

A suggested chain of (conventional i.e. series-connected) effects between guitar and amp could be as follows, borne of experience; 1 Guitar (via a high quality medium length cable)2 Buffer/Line Driver or a Boss/Ibanez electronic switched buffer bypass type effect (can remain off and still improve matters especially if #3 is an MXR Dyna Comp TM ).3 Compressor (if buffer bypassed e.g. Dinosaural you can omit #2)4 High Gain Fuzz or Distortion 5 Overdrive or lower gain Distortion (Dinosaural Tube Bender or Overdriven Preamp, etc)6 Modulation effect(s) i.e. Tremolo, Phasing, Chorusing, Flanging, etc7 Echo and/or Reverberation 8 Level Booster or Preamp for solos etc (e.g. forthcoming Dinosaural model/ Optional Buffer for a long cable run to the Amp (A Wah pedal may be inserted anywhere, but ideally between 3&4 or 4&5 for the most useful effects. Octave dividers and the like work best closer to - i.e. just after - the Compressor end of the chain).

This setup works best if you aim for a relatively clean/clear sound with the FX all in bypass.6 or 7 may of course be operated in the FX loop of your guitar amp if it has one, however:

Avoid placing most floor/battery type stomp box/FX in an Effects Loop on an amp, unless the Send and Return levels are adjustable, otherwise the signal-to-noise and headroom considerations would almost certainly be non-ideal. Ugly distortion and level problems may result from these low-voltage effects "running out of steam" at the higher line-level, and the fact that they are optimized to be used with lower level guitar pickup signals. You may also find that your amp is simply unable to provide its maximum power when configured like this NOT what any guitar player wants!!Only unity gain Modulation or Echo effects (or rather, the rack mount studio variants of these) are likely to work well in the Effects Loop of an amp. Avoiding Hum

On Pedal boards, DC supplies and Daisy Chain connections, while convenient, might cause hum-loop problems within the board itself. The Cable shields already connect each pedal ground together. Having the same ground connection duplicated owing to the DC connector daisy-chain ground is not necessarily a good thing, as mains hum/ground loops could result. If they do (and only if they do) check and determine the offending item by working backwards from the last effect, disconnecting the DC daisy-chain from that effect only and using a battery in it instead. This will isolate it and allow you to readily verify any improvement. If the hum does go away when you try this, then simply disconnect either the signal ground at the effects input jack OR the dc supply ground at the power jack on that pedal but not both! This is getting a bit techy so if it can be ignored, ignore it! Try to avoid running signal cables in-line with AC power cabling if unavoidable, cross them at right angles to minimize induced hum pick-up. Use separate AC Mains power strips for each band member, but try to make them all "begin" from the same origin (this is called Star Earthing/Grounding).

Following the above advice as general principles will help you to avoid future hum nightmares! Never be tempted to disconnect the mains earth/ground connection to a Class 1 mains appliance (i.e. those with metal cases and parts) in a bid to cut out hum loops but find a better signal connection method instead. Having no mains earth/ground connection can be very dangerous on guitar amps, especially valve/tube ones. Good Luck!

Dan Coggins/Dinosaural

Originally drafted: December 19th 2006, Updated : January 29th 2013