AFD100 Marshall 'Slash' Amp Effects Loop

The AFD100 is one of the most anticipated amps to be released in recent times. Find out all about this Marshall Amp and is it worth the effort?

Marshall AFD100 'Appetite' SLASH Amp Effects Loop

The loop in the AFD100 is actually a pretty basic affair and does not really require much explanation. The loop is a SERIAL loop far more useful than a Parallel loop. I am pleased to say on this one Marshall made the right decision.

But you can, (if you don't install anything in the loop) use the loop as a basic boost channel for the lead guitar stuff. The loop has a 10db gain within the circuit so just put the loop knob on full, press the switch and hey presto a 10db gain boost.

You can also set the loop gain knob lower and reduce the volume. Bear in mind that the original amp #39 probably did not have an effects loop.

Below are some interesting facts about amplifier loops... check it all out it's all good educational stuff. 

Here's a little section from the Ultimate Metal Forum about loops:

Originally Posted by Eventide

In any of these scenarios, an FX loop might give an extra choice, particularly on more modern and better designed amps: SERIES or PARALLEL FX LOOP. The traditional FX LOOP is SERIAL, meaning that it is a real break between your combo's preamp and power amp! Consequences? Your pre-amped guitar signal will always go through the digital converters of the connected FX processor and you'll need to use the processor FX balance (dry/wet mix) to set dry and wet (=FX) levels.

The PARALLEL FX LOOP features a straight unbroken connection between the combo preamp and power amp, in parallel with a break between send/return , usually with a send level (to the FX inputs) and a mix level (an FX output level) or, more usually, this last level only. Consequences? Your pre-amped guitar signal goes straight to the power amp, untouched, unconverted into digital domain, staying as your main DRY signal...the real thing, dudes! Your FX processor output is managed in parallel to the dry sound, summed to it. The advantages are many: -signal levels are kept at their natural "levels" , without losing that "in the face" energy you all desire! -tone know what that is, don't you? Better signal/noise ratio!

The only trade-off in PARALLEL FX loops is that typical IN SERIES treatments/FX, like compression/EQ/wah, will be mixed with your dry signal...and this is not what you want when using these FX. Suggestion: use compression/wah/EQ between guitar and amp input, using other gear. Hope: someday a clever guitar amp company will build an amp with switchable and remote series/parallel FX day! If your combo amp does not have an FX loop...well, it must be a dinosaur with classic tones you love too much to upgrade to new technology. In such case the best advice is to have highly qualified guitar amp tech service to modify your amp, adding an FX loop; this is what most pros do. In case you don't want... you can only use your guitar > Eventide > amp front guitar input configuration, all unbalanced, on -10dB.

This is probably the worst possible setup you can use as technology has evolved and necessary adjustments are required to interface "the bold & the beautiful." A serious "con" of this setup is the limitation on using amp distortion: In fact if you are getting your favorite distorted tone from a 1959 Marshall Plexi (no FX Loop amp!) you'll be in trouble as your delays and reverbs will be destroyed, nuked by your amp distortions. In this case, distortion pedals should be used between guitar and the Eventide.

There are many other possibilities that pros use....quite expensive though, like miking an old amp and processing it on the PA..or having the "dinosaur" modified with an added line output that usually feeds digital effects units, going to a stereo power amps w/2 cabinets, strictly dedicated to effects. This 3-amps setup is also called Left FX/Center Dry/Right FX setup.


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