the answers

Great questions, John. There are a couple of really important threads that form the backbone of any discussion on effects loops. Firstly, not all loops are created equal – far from it. They differ in level and in how they’re buffered, driven and recovered, all of which has a massive effect on how they sound, which can be very different from amp to amp. Secondly (and crucially), the common ‘standard’ way to order effects is with the wet effects (delay and reverb) after overdrive and distortion. Which means that if you’re using a distorted preamp in the amp itself, you may well ‘need’ an effects loop to place the reverb and delay after the OD/ distortion. For example…

01 Think about the vast majority of classic amps: AC30s, old Fenders, Marshalls… none of them have loops because they hadn’t been ‘invented’ yet. Loops didn’t turn up until the late 1970s, almost right alongside heavier/cascaded gained preamps. So let’s say you’re using an overdrive pedal and your delay pedal comes after those. It’s all hitting a relatively high-headroom preamp section that – while it may be overdriving very lightly – isn’t into heavier distortion. This is the sound of ages: early rock ’n’ roll, 60s and 70s pop, Mr Gilmour, etc, etc,etc, not forgetting the fact that those old delay units (Echoplex, Echorecs, Memory Man) all had very specific preamp sections/ sounds that were a great contributor to the overall tone in addition to the effect, run straight into the front of the amp.

02 Let’s come forward a decade or two. Companies such as Mesa/Boogie and indeed Mr Dumble start putting overdrive into their amps. Placing delay before an overdriven preamp usually results in a fairly gritty/messy sound that isn’t to everyone’s tastes, so the amp companies needed to find a way to get the delays (and other wet effects in some cases) after the drive. Hello effects loop: a send and return point placed after the preamp and before the power section. And therein lies the key advice. If you’re running a vintage-style analogue-type delay into a high-headroom amp front end, it’s going to sound most ‘authentic’ into the front of the amp. If you’re running a more modern digital delay with a more heavily gained amp, you may well prefer the sound of the delay in the loop. However, effects loops can vary greatly… A series loop puts 100 per cent of your signal through the loop; a parallel loop enables you to mix the effected sound with the dry sound and are best used when your effects have a 100 per cent wet or ‘kill dry’ function.

An ‘instrument level’ (high impedance) loop works well with most pedals, while a ‘line-level’ (low impedance) loop works well with pro rack gear and can cause regular pedals to distort. Most amp loops these days are series/instrument level and may or may not have a send and/or return level to deal with overall levels.

You may also want to try an additional buffer/boost in the loop if you’re running long cables and the sound seems ‘weak’. We hope this helps!