Effects the little magical boxes that change the sound of our guitar. In this "White Paper" we will be talking in general terms about maximizing the effects units. This is not a paper on the actual effects and what they do but more on how to obtain the best results with an effect.
What is an effect, by definition an effect would be any device that alters the original sound of the guitar. Reverb, delays, chorus and flanging all are known as time effects. This means that the equation of time enters into the picture via preset or by manually setting the controls to get a given result. Distortion the stack in the box device. The distortion pedal is probably one of the most used and misused effects today. (See the White Paper on Distortion)

Lets look at getting the most out of a small effects unit, we will use the Boss CE2 Chorus pedal for this example. The guitar is non-discripte at this point so insert favorite model here as long as it can be plugged in. The amplifier in this case will be a standard type with an effect loop.So where do I plug this in to get the best sound? Let's talk about effects loops for a minute, there are two kinds of effects loops Passive and Active. Both types of loops can have send and return controls, a feature that is highly recommended due to the different types of effects units on the market. Think of the effects loop as a mixer. The active effects loop is the better of the two, but to quote Kevin O'Conner "A properly executed active loop only has the "potential" to integrate effects and dry sounds into one. The user has to know how to optimize the effects he is using, regardless of the loop being a mixing-type or series-type."
You will not find effects loops on your mid sixties Fender Twin or Marshall's, they where a product of the late 80s and early 90s with the rack unit craze and as of lately starting to disappear.
I have done some testing with rack units over the years and found that they have thinned the sound out even when the unit was not active. The unit was just plugged into the loop (passive) and turned on but not activated. In this documented case the amplifier was a Soldano Hotrod Fifty;(I have done the same test on Fender amps) the rack unit was a Korg SD3000 delay. When I removed the cables from the jacks the amp sounded, bigger and fuller in tone. I have tried this on numerous amps with much the same results. On some amplifiers you will see a send and a return control, this is the active or buffered loop. The send and return will allow for increasing or decreasing the signal to and from the rack unit but will not allow you to overdrive the next stage. If you clip the input of the rack unit you will get an ugly metallic distortion that is not very pleasing, even the metal guys cringe. The recover stage of the buffered loop is more forgiving but will not give you the gain that you get in your pre amp section. By design the effects loop whether active or passive is put after all the gain stages and right before the phase inverter. Since the phase inverter has no real gain to it the effects that are active in the loop are sitting on top of the guitar signal.

I can see this question coming "So how do I get the best sound out of my effects and amplifier?" Let's do a simple test, take a chorus pedal and plug it into the effect loop. Set volume and tone controls to the desired tone. If the loop has send and receive controls adjust till you get the best sound. Now with out changing any control settings take the chorus pedal, plug your guitar into one side and the other to the input of choice on the front of the amplifier. Usually input jack 1. You will notice that the chorus is fuller in sound and that the guitar and effect are a complete sound. Not like the chorus was an after thought in the first part of the experiment that sounded thin. The difference is a little less noticeable with an active loop but the problem is still there.

Do the exact test over with the distortion pedal and you will probably never use an effects loop again. For those who like the convenience of loops there are two units that seem to have good reputations
1: The Dumbelator built by eccentric Howard Dumble. Rumor has it that Howard is not building amplifiers any more and a used Dumbolator would probably cost you thousands of dollars.
2: Kevin O'Conner at London Power has a good reputation from the news groups postings I have read. I have seen the schematics for his effects loop and it is definitely better than the rest. It works! You can contact Kevin at amps@londonpower.com.

One thing about effects loops if you want one, it means drilling holes and modifying your current amplifier to work. Think about it very seriously before going ahead as the holes are unreversable. Even if you get an outboard loop like the Dumble type (rack mount unit) you will still have to come up with 2 holes for 1/4" jacks to interface the effects loop.

I guess you have figured out I do not like effects loops of any kind, I'm a stomp box person. Lots to choose from, analog or digital, inexpensive and a Fuzz Face sounds like a swarm of bees in an effects loop.
Robs theory on this is that if you put the effect before the amplifier much like the traditional stomp box, you guitar signal and effect are amplified by all gain stages equally. There for you end up with one large signal that has been amplified through all gain stages, not a guitar signal amplified and then the effect added. If you want to see the maximum results of this test use a distortion pedal.

Now I can see some people are going to get bent out of shape over the last couple of paragraphs. There are rack type units that are pre amps that include effects built into them. By design these where meant to be used to be plugged directly into a power amp. There fore you would have guitar; pre amp with built in effects other effects could be added and the designers here where a little smarter and added some gain after the loop, then your power amp and finally your speakers.

Today at some "New Country" concerts you will only see pre amps and antennas (wireless units) in road cases at the side of the stage. They get there sound from the monitors and the audience gets the emulated Fender / Marshall/ Vox sound through the P.A. This is a great concept for a clean stage or the Vegas type shows with big name celebrities and the band in the orchestra pit where space is limited. For most of us the stomp box and amplifier are still king in our quest for tone nirvana.

So Rob, "How do I use my stomp boxes to get maximum sound?" Use your ears. Start by plugging in effects in different orders. I will give you some tips but depending on the effect units you have the order could change. First in line any high gain devices wah wah pedals distortion and fuzz boxes. I will put my wah wah first if I am using one then my distortion pedals. I have found I get a fuller wah sound if I have the distortion on and it is after my wah pedal. This works for me. I did not like the distortion before my wah, sounded a bit thin.

Now you could have multiple distortion / fuzz boxes in the signal chain, Tip: Eric Johnson has his tube screamer before the fuzz face giving it a smoother sound. Again these are only suggestions. You should try different devices in different orders to get the maximum sound that suits your needs. Next time sensitive units such as reverb, chorus, flanging and delays. The tremolo pedal has been making come back and would be added in this part of the chain. A word of caution: The more pedals you add can degrade the signal strength and line boosters may be needed to build the signal back up if you are using some of the vintage effects. I would have no more than 6 units maximum to keep signal degradation to a minimum. Currently most of the players I now use on average between 2-4 effects and some seem to be able to just use there hands and no effects at all.

Effects used wisely add colour and interest to the overall music. Used wrongly they can be seen as a crutch to hide lack of imagination or poor playing. The distortion box falls into this category. Tip the gain control does not have to be on 20 to get the desired effect. Some times the desired effect is fatter not buzzy sounding. Remember the effects are to enhance the performance of the music as a whole, whether it be Blues, Rock or Disco, not to be the only sound of the music.
Use your ears wisely and choose your effects selectively to suite the mood of the music.