| Articles:
Electric Guitar Piezo Pickup Saddles & Bridges: Amplification |
| My name is Alan, and I'm an electric guitar
piezo bridge addict - and happy about it. I started out with the original hardtail
Fishman Powerbridge (the first model available locally), and have never looked back since.
Three out of my four 6-string electric guitars now have piezo equipped bridges, and they
have become an integral part of my sound and playing. In this series of articles, I'm going to take a look at all things piezo:
what they are, how they work, what you can do with them, amplification and FX, some ideas
and sound samples and some pretty advanced applications. |
A bridge fitted with piezo saddles.
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Amplification
Piezo pickups have different amplification requirements from
the conventional magnetic pickups used for electric guitar. Piezos sound best through a
full range system such as a PA, while magnetic pickups sound best through guitar amps.
Two different amps
So the ideal setup is to use two different amps if possible, one full range for the
piezos and a conventional guitar amp. Of course the downside to this is needing to carry
two amps to gigs as well as the additional trouble to mic up both amps in larger venues
and making sure volume levels are balanced.
Using two amps, a full range amp for piezos, and a
guitar amp. Simple but bulky.
Utilising the PA
Another option, which is probably the most commonly used, is to amp the magnetic
pickups as normal and just plug the piezo output into the PA system. This is a very
workable (and inexpensive!) solution, but monitoring must be balanced so you hear the
balance of magnetic to piezo sound accurately.
Using a guitar amp and the PA. Still simple, but
dependant on monitor system.
Using a single amplifier
It is possible to blend the two sounds together into a mono signal, but this means
they have to both go through the same amp, and you have to choose between a guitar amp or
a full range system. Unfortunately this is a bit of a compromise as neither amp can give a
good sound for both sources.
Guitar amp
If you use a conventional guitar amplifier for both sounds, the amp
and speakers do not reproduce frequencies above 4KHz very well, which is where a lot of
the acoustic detail and character lives. So the piezo sound is throttled and does not
sound very natural. Also, if you want to use amp overdrive, it affects the piezo sound
too.
Full range systems
Full Range Systems such as acoustic amps, keyboard amps, PA systems, powered
monitors or a recording desk have the added frequency range that the piezo demands, so
piezos usually sound great plugged into these systems. Unfortunately, through the same
system, the magnetic pickups will sound flat and lifeless and distortion sounds will be
very harsh and brittle.
Full range amp & modelling preamplifier
If you want to use a single amp, there is a solution: use a full range amp
and a modelling pedal or preamplifier for your magnetic pickups. The only additional
requirement is your full range amp must have at least two separate inputs - one for the
piezos and one for the magnetics.
Modelling preamplifiers and pedals (or "modellers")
simulate (or "model") the sound of an electric guitar amp into a full range
system. They usually have a lots of different electric guitar amp simulations, such as
Fender, Vox Marshall, Mesa Boogie and more. More often than not, they also have a range of
common guitar effects built in too. Well known examples of modellers are the Boss GT range
(GT-6, GT-8, GT-PRO), the Line 6 PODs (XT, XT Live, Pro), The Vox Tonelab and the
Behringer V-Amps.
Using a full range amp and a modelling pedal.
Simple and portable
Many electric guitarists will tell you that using a modeller
is a bit of a compromise, not quite the same as using a dedicated valve guitar amp, and
this is true. However, the flexibility, affordability, reliability and portability
advantages outweigh the disadvantages in this application. It will allow you to get a
usable range of sounds from both instruments without breaking the bank or your back. The
ability to take a direct line out from your full range amp into the main PA will also make
you quite popular with your sound engineer.
Connection and setup is simple: plug the piezos directly into
one amp channel, plug the magnetic pickups into the modeller and then plug the output
of the modeller into the second input of the amp.
Bigger systems
The most flexible amplification option is to use two rack modellers or multi FX,
one for each the piezos and magnetics, both feeding into a racked submixer. This is the
only way to go if you are also using a MIDI guitar (guitar synth) system, as it means
everything guitar related: piezos, magnetics and synths, can be kept in one rack and
submixed by a rack mixer, before going off to the amplifier and speaker system. It also
allows you to change sounds on all the gear at once using a MIDI footswitch.
A larger rackmounted setup with magnetic and piezo
sounds as well as guitar synth. Maximum flexibility and consistency, but fairly
complicated .
This system can be hooked into the PA wherever you play. Add
As a bonus, this system can double as your PA in a smaller venue. In larger venues you can
send the guitar mix to the house desk and use the power amp and speakers as a monitor
system.
NOTE: If you are using a modeller for the
piezos, make sure that the amplifier and speaker simulations are turned off for more
natural piezo sounds.
Software
One final option remains: using a software modelling "amp". Specifically,
Native Instruments Guitar Rig lets you process two guitar signals simultaneously, allowing
you to set up different effects and amplifier models for each. The key to doing this is to
use the powerful "Split" tool with the "stereo input" button turned
on. The channel with the electric guitar sound can be set up with normal amp models, while
the piezo channel is set up with a DI box model (one of the speaker simulation options)
and FX to taste for each separately and together.Unfortunately
very few computers are gig-ready yet - with the exception of some specially built, rack
mounted machines which tend to be quite expensive. I also have this nightmare of having to
apologise to the audience because my guitar amp has a virus! So this option is best suited
to using at home or in the studio for now, but definitely worth keeping an eye on. |
(click for large image)
Guitar Rig set up to process magnetics and piezos simultaneously.
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