After the recent release of the new Boss GT-8 Guitar processor, I noticed a flurry of adverts on Musicads and in the newspapers, selling off the older (but still good) Boss GT-6 and other similar processors. Now for some, the reason for doing this is to help finance the upgrade - we've all been there! However, for those who can afford to keep their older FX processor, there is a very attractive option available - using the older unit in parallel with the new to do some very nifty things indeed. While this article is written specifically with guitar in mind, this is not only something guitarists can use!

Parallel Effects revisited
You will remember a while back I wrote an article on parallel effects - If not, you can find it here. To sum up: When running effects in parallel, we drive the inputs of two or more effects with the same source signal by splitting it into two or more 'branches' or 'chains'. Then the outputs of the two branches can be combined using a mixer. This gives a range of sound combinations not available with series processing - allowing more than one different sound  (like a clean sound and a distorted sound) to be mixed together.

With two multi effects processors, you have the freedom to take things further than you can with a few pedals - each branch can have it's own overdrive and distortions, and even dedicated reverbs - which are often to processor intensive to be able to have more than one in an effects unit. The icing on the cake is that, with most FX processors made in the last 10 years or so, there will be amplifier, speaker and even microphone modelling. The upshot of this all is that you can give each branch it's own, distinct sound - in effect, making it sound like two different amplifiers and even (with the right tricks) making it sound like a double-tracked guitar part. All live and real-time.

The return of Splitting the Signal
The methods I previously mentioned for splitting the signal into two chains were: splitting buffers (sometimes called 'Spluffers'), DI boxes, stereo mixers and stereo effects. All these will still work, but with many multiFX processors you have even easier and more flexible methods, namely:

Buffer Outputs - Many units have a "buffer" output, specifically for driving other processors or amps. These outputs give you an identical copy of what you are putting into your input, and are obviously perfect for this application.

Tuner Outputs - Some units have tuner outputs, which are basically glorified buffer outputs.

Effects Loops - Finally, we have the humble effects loop, which is designed to allow you to insert one unit in the internal signal path of another. Normally this is done with a send jack and a return jack (often two returns, to allow for the return signal to be stereo). However, wiring it up this way places the second unit in (plain old boring) series somewhere in the signal path of the first. To use the second in parallel, you don't use the return jacks on the first unit - you plug the outputs of both units into a mixer and the mixed signal to the amplifier. Of course, you could use two amplifiers, one for each, but it is usually more practical to have one.

Conventional method of using a second effects unit in the loop of another, effectively placing it in series	Connecting the second unit so it is connected in parallel

Where the effects loop is really powerful is that the settings for the loop (on/off) can be written into a patch on the master unit (usually your newer one) so you can have your second unit set up to work on one patch and be switched out of the next - a very powerful feature. You will often be able to bypass the effects loop via a pedal on the master unit too, allowing the second unit to be bypassed with a floor pedal switch without changing patches.

Many better effects units will allow you to specify where the loop is placed in the internal chain of effects, allowing you to use it before amplifier and speaker emulation (for instance) in one patch and after it in another.

The Bride of MIDI
If your master effects unit is capable of sending out a MIDI program change message, it is easy to plug a cable from the MIDI Out on the master to the MIDI In on the second so that changing a patch via the pedal on one changes the patch on the second at the same time. Take some time to read the manuals and find out if a nifty feature called patch mapping is supported as this lets you have the second change to a different patch number from the first.

The Return of the Son of Tips and Tricks

• Try a short (1-12ms) delay on the second unit. Use only the wet signal, no direct - this can really make the two stand out from each other.
• Building on the last point, longer delays can be made to sound really different from the original  by using different amp and speaker sims.
• If you are working in studio (or anywhere where you can experiment with stereo), take the time to position things carefully to get the best separation between the sounds. I often like to have a dry sound panned on or near centre with the second panning around the extremes.
• Keeping one sound relatively dry and tight with fewer and more subtle effects will make sure that you can mix things to make it stand out, regardless of how many effects are used for the second sound.
• Using similar reverbs on both sounds will make them mask and blend together better - sounding like they are both being played in the same space. Using different types of reverb can make them stand out from each other.
• Experiment and keep an open mind, some of the best sounds are found by "happy accident"

Audio Examples
For some audio examples of what can be done, visit www.ratcliffe.co.za - I'll be putting up some example mp3 downloads there.