Fx Loops

hotpickups

Am I right in thinking that any modulation i.e. Tremolo, Phaser, Delay etc is fine going into an amp's fx loop? But never an overdrive pedal etc?

viz

Yep. (Some do put OD in the loop but it’s not advised / nice)

hotpickups

viz said:

Yep. (Some do put OD in the loop but it’s not advised / nice)

Damage the amp I suppose if one did?

viz

hotpickups said:

viz said:

Yep. (Some do put OD in the loop but it’s not advised / nice)

Damage the amp I suppose if one did?

I recall ICBM and others saying some OD/amp/loop combinations are safe, but it’s better not to just in case. 

ICBM

Yes, it is possible in rare cases to damage the amp if you put an overdrive (or distortion, fuzz, or external preamp if it's creating distortion) in an amp's FX loop. The cause is signal from the return of the loop leaking back to the send via the amp's circuitry (usually the power supply) - if whatever's in the loop has enough gain, it will re-amplify that signal and can make the amp feed back internally, usually at an extremely high frequency outside the audio range, and self-oscillate at full power. This will make the sound very odd and/or compressed, and in the worst case it can overload components which aren't normally expected to have to handle that much power.

More commonly, it will just sound bad, but it's not a good idea to try just in case - if it feeds back outside the audio range you won't be aware of it until you try to play something, and the damage can have happened already.

It *is* safe to simply connect the output of an external preamp, multi-FX with distortion or whatever to the amp's FX return, *without* coming from the send first - because there is then no way the signal can feed back to the input of the unit.

markr76

I pop my delay and my tc electronic  spark boost into the loop. I use the boost to get a volume lift for solos. I used to use an eq pedal and push the mids a bit for the solo boost. But find the spark does a better job. 
I only use this if there's another guitar player in my band, which there is at the minute. I use a badcat hotcat 30r. If I was only using the clean channel I'd pop the boost up front after the od pedal. 
Everything else I prefer in front of the amp.