Effects Loops - Serial vs Parallel

[9-Pin-Phoenix]

OK what is the difference between the two types of effects loops? When would I use one over the other? With what types of effects? Does one sound better? Just trying to get a handle on this. The amp I currenlty own doens't have one, but I am looking at an amp that has one of each, and I want to see if this is something I am going to make use of. Thanks.

[9-Pin-Phoenix]

Anyone?

[session_of_jam]

.........Good Question. I would be interested to hear the discussion on this aswell.

[MorePaul]

OK, basically the FX loop is an opportunity to connect something between the preamp section and power amp section of an amp

 

In this way, the preamp is treated almost like a "pedal" in that you can choose to put it wherever in the signal chain

 

 

A serial effects loop puts things after the preamp in a series connection (ie the signal flows from the preamp into whatever is in the loop, then to the power amp) and behaves like a typical "plug this into that into that" type pedalboard

 

A parallel FX loop has "parallel" signal flow (signals running 'side by side'). In a parallel FX loop the signal comes out of the preamp and is split

one signal line (let's call this line A) runs throught the stuff connected in the FX loop, just like a serial connection

The other line (line B) goes from the preamp right to the power amp

 

So what you get is a MIX of the "straight through" signal and te effected signal -- some units will have an FX loop mix control usually on the back

 

The design theory is that, with a parallel loops, you get your "straight through" sound, uncolored, adulterated, or "tone sucked" by whatever is in the FX loop

with the stuff in the FX loop offering some 'ehancement'

 

The parallel loop is probably "best used" (I put that in quotes, b/c I mean that in a design theory sense) with ambience type effects that put another "image" on top of the original sound...such as reverbs or delays

Other effects can get a lost or a bit more subtle as you have the "dry" sound is concert with the effected sound (which, in practice, can be a very nice thing as it can make some effects less obtrusive and tiring -- bass amps are good candidates for parallel loops as the "dry sound" is so often the foundation with just splashes ofcolor added by treatments)

 

[Note - while it is most common for "pedalboards" to be set up in just straight series, there's a lot of really nice xpressive potential in parallel routings even within the context of a pedalboard (with modern DSP multi-effects one can set this routing up in software) -- I believe Indocityoffunk uses a parallel connection around a filter on his current set up, as an example]

 

Setting mix (if avail) with a parallel loop can be important to get the desired effect

 

Notice that some effects (chorus,phasing,flanging for instance) are actually composed of parallel "images" internally, so you can "throw off" (the designed balance between the images) with the additional dry signal

 

effects like Delay, verb, etc that have their own dry mix control will also need to be readjusted for balance

[scott_335]

I prefer serial because my effects have mix knobs already, and if there is tone suck, the pedal will be in a TB loop

[MorePaul]

One thing about "tone suck" to bear in mind that I think get's underadressed

 

"tone suck" also happens when an effect is engaged

[9-Pin-Phoenix]

Originally posted by MorePaul OK, basically the FX loop is an opportunity to connect something between the preamp section and power amp section of an amp In this way, the preamp is treated almost like a "pedal" in that you can choose to put it wherever in the signal chain A serial effects loop puts things after the preamp in a series connection (ie the signal flows from the preamp into whatever is in the loop, then to the power amp) and behaves like a typical "plug this into that into that" type pedalboard A parallel FX loop has "parallel" signal flow (signals running 'side by side'). In a parallel FX loop the signal comes out of the preamp and is split one signal line (let's call this line A) runs throught the stuff connected in the FX loop, just like a serial connection The other line (line B) goes from the preamp right to the power amp So what you get is a MIX of the "straight through" signal and te effected signal -- some units will have an FX loop mix control usually on the back The design theory is that, with a parallel loops, you get your "straight through" sound, uncolored, adulterated, or "tone sucked" by whatever is in the FX loop with the stuff in the FX loop offering some 'ehancement' The parallel loop is probably "best used" (I put that in quotes, b/c I mean that in a design theory sense) with ambience type effects that put another "image" on top of the original sound...such as reverbs or delays Other effects can get a lost or a bit more subtle as you have the "dry" sound is concert with the effected sound (which, in practice, can be a very nice thing as it can make some effects less obtrusive and tiring -- bass amps are good candidates for parallel loops as the "dry sound" is so often the foundation with just splashes ofcolor added by treatments) [Note - while it is most common for "pedalboards" to be set up in just straight series, there's a lot of really nice xpressive potential in parallel routings even within the context of a pedalboard (with modern DSP multi-effects one can set this routing up in software) -- I believe Indocityoffunk uses a parallel connection around a filter on his current set up, as an example] Setting mix (if avail) with a parallel loop can be important to get the desired effect Notice that some effects (chorus,phasing,flanging for instance) are actually composed of parallel "images" internally, so you can "throw off" (the designed balance between the images) with the additional dry signal effects like Delay, verb, etc that have their own dry mix control will also need to be readjusted for balance

 

Great information! Thanks.

[Seano Porno]

Marked for later....i know it's OLLLD but I ain't read it yet.