Distortion in effect loop

[one]

So today i went to my local music centre to get myself some new leads for my effect loop, and after talking to the owner for a while he asked my if i will be running a distortion in my effect loop, i replied yes. After this he told me that i should not be doing this a i will damage my amp.

He had previously phoned Marshall up about running a eq pedal through a effect loop on a marshall sysem, spoke to the main designer of the amp/s and he told him not to run any eq/distortion/over drive/fuzz through a effect loop. He said eq's/dis/od/fuzz are done by boosting the signal and signal boosts are not intended to be put in a effect loop and the signal should stay a constant through the loop.

I trust the owner of the store and i was wondering if this is entirely true for every make of amp, bass/guitar, etc? has anyone else heard this?

if this info is true, then unplug those eq's and distortions and put them infront of your amp!
(just thought some of you might like to know this info as i didn't know about this!)

 

[DbNBassist]

erm, i dunno, never heard it before, but i know Matt Bellamy and Tom Morello both run EQ's in the effects loops, and as for distortion, i dunno what it does, but i tried it once in the effects loop and it sounded horrible.

 

[excane]

Distortions sound best the way the hot signal hits the front of your preamp.
Modulation effects tend to work fine in the effects loop.

 

[EricF]

If it's a gain pedal (OD, dist, etc.), it's probably designed for an instrument level signal and therefore should be before the preamp. Generally speaking, the effects loop of your amp will want things that are designed for a line level signal.

 

[niftydog]

Firstly, I doubt you're gonna blow anything up, but it is a remote possibility I suppose. What you will do is overload the return circuit causing unwanted clipping. However, set the volumes right and you won't have a problem.

Secondly, disto sounds terrible in FX loops because it's post preamp and EQ (in some amps) and it just doesn't work.

Thirdly, FX like EQ and distortion aren't achieved by boosting alone. Set correctly, your EQ pedal will produce the same volume but with shifted frequency response. So, while I agree there is the potential to overload the FX loop return circuit, done carefully there's no issues at all. You can easily set up your disto and EQ so that the signal level is constant through the FX loop.

Further, distortion actually plays a little trick on us. Say you set up your distortion to have the same apparent volume as your bypassed sound. Then, record both sounds and analyse the waveform and you're in for a surprise. Distortion causes severe compression of the waveform. While you are hearing the same average volume level, the reality is that the peak amplitude is actually much less than that of the bypassed tone.

As it happens, I have an example that I made using Marshalls own Guv'nor pedal. (So, that guys explanation left a lot to be desired as he should have been well aware of this phenomenon!) Note the first third of the waveform is clean, bypassed tone, the second third is natural decay, then I switch on the Guv'nor and start playing normally again. Note the drastic difference in peak amplitude even though I'd set it up so the volume appeared to be the same.
Link Removed

 

[jasonbraatz]

Most distortion pedals don't sound good in the FX loop, but the Sansamp RBI has the ability to switch between line and instrument level, plus a nice blend control and footswitchable bypass.

I just got one and hooked it all together, and it is SMOKIN.

 

[EricF]

niftydog - That might be the most informative piece of info I've seen in a long time.