FX loop 101

[enuenu]

I have finally decided to just stop using my pedals the old fashioned way (strung together between guitar and amp input) and work out how the FX loop is used. I went to the manual but could make neither head nor tail of any of it. It is mainly the language used I guess. Processor's input, patching effects, unity gain, sends and returns. This is all Greek to me.

High quality cable to be used (= good guitar leads or speaker cab leads? Not sure what the difference is, but I believe they are not interchangeable).

I have technical knowledge in other engineering areas but this is new to me. I suppose I'm trying to say I'm not an idiot. I just play guitar.

Can anyone direct me to a dumbed down version of how to use the FX loop in combination with the footswitch controls? A few schematic diagrams showing how the cabling should be connected would be great. Then when I work that out I can start to consider why people modify their Recto's FX loop (and maybe do it myself one day).

 

[jbird]

You would mostly only need delays or reverbs in your loop! Things like distortions, od's, boosts, wahs, compressors, and tuners would stay in front! Modulation effects ( chorus/phasers) are subjectible! Lower all channel masters and outputs, place the effects loop on ('HARD BYPASS" off), start with the effects loop send level on the rear at 50% (usually indicated "normal"), place a patch cable/instrument cable from the send jack on the rear to the input of the 1st effect, and so on, then the output of the last effect back to the return of the effects loop on the rear! Set your channel masters moderately (10:00?), you'll have to balance the channels, use the master output for overall volume! The send level on the rear is really for fine tuning the channel master levels (effects send) to the effects units, most people would probably do fine around noon as mentioned! You'll have to balance/ see what works with the individual levels of each effect!
Of note: there is a sound degradation associated with empoying an effects loop on any amp, but with some effects like delays/reverbs, if you must, then you'll have to compromise, of course, having a bunch of effects up front is degrading too, sooo....
Anyone else add....

 

[thunda1216]

might add that speaker cables are *not* suitable for patch cables as they are not shielded and may introduce rf(radio frequency) noise into the signal chain...

 

[harem_theater]

I hope this picture can help you

As you can see, an amp is made up of two parts, a pre-amp and a power amp.

In short, the preamp dictates the overall sound of your tone i.e gain, eq and general shape...

...and the power amp pushes it through speakers loud enough so you can hear it.

somewhere along the line, there needs to be a wire connecting the two together (the brown line, also known as 'hard-bypass')...is this state, the fx loop is inactive and any fx in the loop will not be heard.

IF you wish to have fx AFTER the preamp and BEFORE the power amp (which is generally the "preferred" way for time-based fx like delay, reverb, chorus, flanger and sometimes phaser), you can then utilise the fx loop in the amp.

"SEND" obviously 'sends' the signal out of the amp to the fx and return takes the output of those fx and 'returns' them back into the power amp

There are 3 different types of FX LOOPS:

Serial - when active, 100% of the signal runs through the fx loop...great for external EQ pedals, harmonizers etc. When inactive, obviously the signal bypasses the loop and goes straight to the power amp.

Parallel - this is a little more complicated as it has a 'mix' knob which blends the fx loop signal with the direct signal. great for when you have a delay that has no dry signal passing through it so you can get your dry signal by lowering the fx loop signal

hope this helps

 

[konstantine RK]

stick to the serial loop type.... less headaches with technical stuff and the levels when using effects and running your amp dry. Parellel loops can be a pain in the ear!

 

[enuenu]

I hope this picture can help you

As you can see, an amp is made up of two parts, a pre-amp and a power amp.

In short, the preamp dictates the overall sound of your tone i.e gain, eq and general shape...

...and the power amp pushes it through speakers loud enough so you can hear it.

somewhere along the line, there needs to be a wire connecting the two together (the brown line, also known as 'hard-bypass')...is this state, the fx loop is inactive and any fx in the loop will not be heard.

IF you wish to have fx AFTER the preamp and BEFORE the power amp (which is generally the "preferred" way for time-based fx like delay, reverb, chorus, flanger and sometimes phaser), you can then utilise the fx loop in the amp.

"SEND" obviously 'sends' the signal out of the amp to the fx and return takes the output of those fx and 'returns' them back into the power amp

There are 3 different types of FX LOOPS:

Serial - when active, 100% of the signal runs through the fx loop...great for external EQ pedals, harmonizers etc. When inactive, obviously the signal bypasses the loop and goes straight to the power amp.

Parallel - this is a little more complicated as it has a 'mix' knob which blends the fx loop signal with the direct signal. great for when you have a delay that has no dry signal passing through it so you can get your dry signal by lowering the fx loop signal

hope this helps

Thanks a lot, very helpful.

This part I don't quite understand;
Parallel.......great for when you have a delay that has no dry signal passing through it so you can get your dry signal by lowering the fx loop signal
Not sure why time based pedals are suited to the parallel loop. Is the reason that they all have "no dry signal passing through"? I didn't realize my non-time based effects DID have dry signal passing through when they were switched on. The previous two sentences may be nonsense. Got to look silly to learn sometimes

 

[UnderJollyRoger]

No, actually, most Delays I know have a mix knob to adjust the dry/wet ratio ...

IF there would be one with only wet signal, you would need a parallel loop to be able to hear the dry signal ... doesn't make sense to me anyway, since without a parallel loop, you would only be able to hear the wet signal which sounds quite confusing ...

 

[harem_theater]

The point i was getting at is the best way to use a parallel loop which in my opinion would relate to...


when signal runs through a pedal that is turned on, in most cases (like with delays and reverbs), the tone in that signal is compromised (slightly at least).

When you have a "mix" control on one of those pedals and you're running it through a serial fx loop, 100% of that signal is passing through the pedal, therefore any tone degredation caused by the pedal (even when the mix control on the pedal is at 0% leaving no intended effect on the signal) is completely unavoidable.

HOWEVER, a way to get around this is to use the supplied parallel fx loop on your amp, set the 'mix' control on your pedal to 100% wet, and then you can use the 'mix' control on your parallel loop to control how much of the fx signal passes vs the dry signal.

See how the red line (being the purest signal possible) runs all the way from pre to power with a parallel loop (on the left) whereas with a serial loop (on the right) you have no choice but to accept any tonal alteration made by your fx as it's ALWAYS running through your pedals.

I hated the fact that Mesa only had parallel loops on there amps before as i use a G major with a volume pedal to control fade in/out and it NEVER worked properly on a parallel loop because the mix only goes up to 90% which left 10% of my unaffected signal still running through so i could never completely cut the volume out.

But with the serial effects loop, you don't have the option to blend pure signal in with pedals for the sake of recording and so forth.

I would have preferred they use a serial/parallel loop (essenatially a parallel loop but the mix can go to 100% wet) so both of these options were available...but the serial loop they have now is still pretty damn pure. Just gotta make sure you run goood quality fx so the tone doesn't turn to poo.

Confusing??

 

[enuenu]

harem-theater, thanks a lot for taking the time with the great explanations. I will re-read all the posts and the manual carefully and come back if I am still in the dark on anything. Thanks again.

 

[harem_theater]

happy to help. i don't post much but i know fx loops can be tough to knuckle so it's a pleasure

 

[cheameup]

Hey man

Biggest thing to remember is the loop is after the preamp distortion . So before the amp your distorting the effect , in the loop your effecting the distortion .Makes a big difference to how the pedals will sound

I like the mesa loop as i keep it on 50% mix between dry and loop . I was maxing the loop mix for a while but I'm back to 50% (12:00) . It sounds better for most things for me . I also have my loop send at 12:00

I have in front of amp - tuner, EHX Hog , MXR EQ (which I am using as a clean boost for heavy chugging sections )
In Loop SIB Vibrato, DD20 delay and Spring chicken reverb