*I DID Search* Effects Loop

Fullmetal · #1 08-10-2009, 06:12 PM

This is something I have come across alot on the effects forum. Effects Loops. I know you can get switches so you can choose which loop your currently playing through, but heres something I've recently discovered.

A friend of mine has been using an MXR 6-band EQ + Boss SD-1 (he's a guitarist) for a while now, but he recently started using the effects loop through his amp. Now he's selling the SD-1 and adjusted his EQ settings completely.

Now I've spent quite a bit on pedals, and I don't wanna have to end up selling pedals or changing settings, but how does running through the amp effects loop differ from not running through the loop? I currently run my effects as - Bass -> Pedalboard -> Amp.

Is it neccessary to use the effects loop? Does anyone here do it and notice any change in sound? I did do a search but couldn't find much about Amp Loops.

**TheMutt** · #2 08-10-2009, 06:22 PM

Generally speaking, effects loops on amps are designed for signal processors that can handle line level signals. This is because the majority of effects loops are placed after the preamp and just before the power amp of the amplifier. Effects pedals are generally designed for use at instrument level, that is to say, running between the instrument and amplifier/preamp input instead of in the effects loop. Rack mounted effects, and some exceptions to stomp boxes (Eventide pedals for instance) can be used as intended within the effects loop, but I know that there are some on here who will tell you that they have been using effects in their amp's loop for XX number of years with no problems. AFAIK, it's not going to damage anything by running your effects in the loop, but they definitely won't sound the same as when run directly after the instrument.

niftydog · #3 08-10-2009, 10:13 PM

MODS! This should really be added to the FAQ - the info about FX loops is a bit lacking.

Your average amplifier signal chain goes something like this:
input > preamp > FX loop out > FX loop in > power amp > speaker out

(When no jacks are plugged into the FX loop sockets they effectively short together, feeding the preamp directly into the power amp. HINT: The failure of the switch is a very, very common amplifier fault.)

FX between your bass and the amp go before the preamp, hence they get fed a low amplitude, high impedance signal from your bass.

FX in the FX loop go AFTER the preamp, which means they generally get a higher amplitude, lower impedance signal from the preamp. This also means they are affected by changes to the amplifier settings (EQ, compression etc.)

Just about all FX pedals are designed for the signal coming directly from your bass. But that shouldn't stop you experimenting.

dingbass · #4 08-10-2009, 10:42 PM

Quote:

Originally Posted by niftydog

MODS! This should really be added to the FAQ - the info about FX loops is a bit lacking.

Your average amplifier signal chain goes something like this:
input > preamp > FX loop out > FX loop in > power amp > speaker out

(When no jacks are plugged into the FX loop sockets they effectively short together, feeding the preamp directly into the power amp. HINT: The failure of the switch is a very, very common amplifier fault.)

FX between your bass and the amp go before the preamp, hence they get fed a low amplitude, high impedance signal from your bass.

FX in the FX loop go AFTER the preamp, which means they generally get a higher amplitude, lower impedance signal from the preamp. This also means they are affected by changes to the amplifier settings (EQ, compression etc.)

Just about all FX pedals are designed for the signal coming directly from your bass. But that shouldn't stop you experimenting.

One additional thing to add here is that some tube amps (some of the Orange guitar amps and some other) will run pre-amp tubes for input/output of effects loop wich can really help to warm up tone.

newbold · #5 08-10-2009, 10:56 PM

MY FX loop is parallel and the circuit gets noisy when anything runs through it.

I wish it were in series so I could run the front end of my amp through my FX and not drive it so much with EF and synth...to be able to use it in line and bring out the strengths of my amp's pre and compressor, not to mention the onboard EQ.

It's all signal processing after all.

Mark Olson · #6 08-11-2009, 11:00 PM

Definitely. One of the first things to know about effects is not to run most of them through an effects loop. I was greatly irritated the other day when browsing effects reviews on musiciansfriend to read reviews of a certain bass fuzz pedal that received many low ratings because bass players were running it through their effects loops, which of course caused it to be very noisy not to mention not sound as intended. Reading that sort of stuff makes me lose faith in bass players in general.

bassplyr5150 · #7 08-19-2009, 07:12 PM

Mr. Olsen, all I can say is that some of us are not the sharpest tools in the shed. Myself included.

I have been wondering about the use and usefulness of effects loops all afternoon, and have finally stumbled across this thread.

I thank you and TheMutt for enlightening me on the subject.

Bassman203 · #8 08-19-2009, 07:22 PM

One very good use of an effects loop is if you have a delay pedal and use amp distortion. This way you can have the delay after the distortion, and I'm pretty sure that makes it sound less muddy. I haven't had personal experience on this, but I'm pretty sure I got my facts straight (at least for the most part)

shineofleo · #9 08-19-2009, 07:27 PM

Take BOSS DD-20 for example, it is a instrument level board right? So if it is put in the FX loop, a pre-amp is needed after it, to amplify the inst. level signal from DD-20 and send to FX return.

Is it correct?