Product Review  by Greigg Fraser

“PZ- Pre Acoustic Instrument Preamp” by Radial Engineering Ltd.

www.radialeng.com                                   info@radialeng.com

Radial Engineering (a Canadian based company out of Port Coquitlan BC) have created quite the buzz among musicians and audio experts alike for several years now, producing everything from cable assemblies and direct boxes to a full line of guitar pedals all with outstanding sound quality and durability.

The subject of this review, the “PZ- Pre Acoustic Instrument Preamp” is part of their popular “Tonebone” series of guitar pedals. It’s called an “acoustic instrument preamp” for good reason for although many would assume it’s primary function would be as a guitar preamp, it’s designed for almost any acoustic instrument imaginable; mandolin, banjo, violin, dobro etc. Lets talk features…

Housed in the standard “Tonebone” series 14 gauge steel stomp box, the PZ-Pre has 2 separate channels, (with a footswitch to toggle between them) 4 separate outputs including ¼ inch unbalanced outs for a tuner and stage amp and two XLR balanced outs; pre and post eq respectively. There’s also a 4 band semi-parametric eq, notch and lo cut frequency filters, separate level controls for each channel, a 10db switchable (and adjustable) clean boost, effects loop and a mute switch that cuts all outputs except the tuner out. There’s also a phase adjustment switch that inverts the signal polarity to match whatever instrument is plugged into the PZ-Pre. The input of channel one has a built in piezo buffer, activated by a small recessed switch. This allows the user to plug in an instrument that features either a passive or active pickup system. The PZ-Pre is powered by a 15VDC-400mA “wall wart” which is included as well as a clear and informative user guide/owners manual.

Now for the “Road Test.” Needless to say the PZ-Pre passed with flying colors! I play in an all acoustic classic rock band and the PZ-Pre meets my on stage requirements to a tee. Both my acoustic guitar and mandolin have separate channels so a quick change is never a problem. The boost is wonderful for solos…boosting my signal without coloring the sound one little bit. The effects loop (activated by the booster switch) allows me to add a delay pedal to “sweeten up” my solos and not be in my regular signal chain when I’m playing rhythm. The eq is both “musical” and versatile and with the notch and lo cut frequency filters, on stage feedback is never an issue. The unit is very quiet and powerful sounding providing a clean signal to both the mixing board and my on stage amp. It’s certainly made my life easier as it also has for John Jorgenson, James Taylor, Keith Sewell (Dixie Chicks) and a host of others. A truly great product…Thank you Radial!

“Just Plain Nuts”

The nut is one of the most important exponents in the overall performance of any guitar…electric or acoustic. A badly worn or poorly made nut can hamper the playability of your guitar as well as the tone and tuning stability.

Nuts are made from a variety of materials including; plastic, bone, micarta, brass and graphite. Bone is usually the number one choice for many guitarists and guitar techs alike, mainly because of the tone. For electric guitars with a vibrato system my personal choice is a nut made from a “low friction” and self lubricating  material such as graphite. (using the vibrato bar dramatically increases the chance of the guitar strings “snagging” at the nut)

The main reason for nut replacement is simply when the old nut is too badly worn, with the string slots carved so deep that the strings tend to “fret out”  or buzz at the first fret. This can sometimes be corrected by gluing a shim (a small piece of material about the thickness of a business card) under the old nut. However if the wear is too severe…a new nut is usually the answer.

A great way to check nut slot depth (and possible wear) is to press down any string down at the 3^rd fret. There should be enough clearance between the string and the 1st fret to slide in a piece of paper…or so. If the string is touching the fret, and you’re experiencing buzzing when you strike the string “open” then a new nut may be in your future.

Making a new nut from scratch is a tall order requiring an experienced guitar tech and about an hour or so of his/her time. The job calls for several special tools such as precision nut slotting files, razor saw, nut seating files, chisels etc.

Another alternative is to see if your guitar is a candidate for a “pre fab” nut. These nuts are manufactured with the width and height predetermined as well the individual nut slots already “roughed in.” If you find one that fits your guitar, installation is quicker and a bit cheaper.

Guitar Effects Primer

By Greigg Fraser

As a guitar teacher I am frequently asked a variety of questions about effects by my electric guitar students, such as; What are they? What do they do? Which ones should I get? (etc.) With this article I will cover “pitch shifting” or “modulation effects.”

“Chorus”  Perhaps the most widely used modulation effect, is so called because it makes your guitar sound like more than one…thicker and usually a bit “sweeter” sounding. This is done by electronically  “cloning” your original guitar sound and adding delay or “modulation” (which is shortening or lengthening the delay) to the cloned signal. Although it can be used as a solo sound this effect is generally used for a clean rhythm sound…I think of Andy Summers (the Police) and Adrian Belew (King Crimson) when I hear this effect.

“Flanger” As with the chorus effect, here the signal is split or cloned and a  short delay is simply added to the cloned signal…then mixed back in with your original signal. This delay has several repeats with the time of the repeats being lengthened and shortened at a steady adjustable rate. The resulting sound is usually much thicker than the chorus effect. Check  out the Queen song “Keep Yourself Alive” to hear it for yourself.

“Phase Shifter”  Once again your guitar signal is cloned… modulating the phase of the cloned signal and mixing it back with the original signal. As  a result certain frequencies are cancelled all together resulting in a “swooping” or “twisted” sound. Eddie Van Halen used this effect a fair bit

        on his early recordings.

“Vibrato”  With this effect the entire signal’s frequency is modulated creating a slightly “out of tune” sound at a steady and adjustable rate.

“Temolo” Similar to the vibrato effect where the entire signal is modulated, but this time the volume level of the guitar signal is what is effected…louder

“Pitch Detune”  Here again the original signal is cloned and the clone is electronically changed to another note all together, say a 5^th of the original sound creating a “parallel” harmony.” Listen to Trevor Rabin’s solo in the Yes song “Owner of a Lonely Heart” to hear this effect.

Modulation effects can greatly enhance your guitar sound and are a lot of fun to experiment with. You can get all of these and more in most of the multi effects pedal boards/units that are out there like the “Boss GT8”, “Digitech RP250” and the “Damage Control Glass Nexus”.

“String ‘Em Up!”

A much over looked but very important technique for any guitarist is how to properly re-string their instrument. In this article I’m going to focus on installing steel strings and leave nylon or classical guitar re-stringing for another time.

First off…be aware of the string gauge you’re using…in other words, what your guitar has been set up with. If you change the gauge you’ll likely have to re-adjust your truss rod and intonation. Also, it’s good to stay with the same brand of string once you’ve found one you like. Time and time again I’ve found that even if you’ve kept with the same gauge, changing brands can result in further intonation adjustments.

The first method of re-stringing we’ll discuss is the one I mainly use which I call the “Lock Wind.”  First, turn the tuning key until the hole in the string post is in line with the nut slot. Next, pass the string through the hole pulling it up so there’s about 2” between the fingerboard and the string…keeping the string taught at the bridge end. This should allow for about 2 or 2 ½ windings on the string post once you’re done. You don’t want anymore that…excessive windings can cause the strings to slip. Next you pull the string toward the centre of the headstock and loop it underneath and over itself up against the string post. Then start turning the tuning key…winding the string on the post. Be sure the windings go from the top down, thus creating a greater angle from the string post to the nut. This puts more downward pressure in the nut and increases your sustain. By installing the string in this manner, it will have wound around itself once giving it something to “hang onto.” Once properly stretched, you’re good to go!

Now we’ll talk about stringing a guitar with vintage Kluson style tuners, which have a split post (these are found on many Fender Strats and Teles). What you do, is pass the string through the bridge and pull it tight. Measure about 2” past the string post of the string in question (I use the handle of my plastic string winder to measure with) and cut the string. Now stick the cut string end down the centre hole of the post and start winding. Cutting the string like this will give you about 3 windings on the string post, and once again be sure to wind from the top down…

“Adjusting The Truss Rod”

Unless you own a guitar which sports a “composite neck” (such as carbon fibre, graphite or aluminum such as Steinberger or Travis Bean guitars) from time to time you will need to adjust your guitar neck’s truss rod. Most guitar necks are made of wood of course, and wood reacts to changes in both temperature and humidity…expanding and contracting. These changes can cause a variety of problems such as; fret buzz, high action, intonation problems and dead or “fuzzy” sounding notes. Often these problems can be corrected by adjusting the truss rod.

The truss rod is a long metal bar under your fingerboard, which extends through the length of your guitar’s neck. It is adjustable either at the headstock under a small plastic plate (as with a Gibson or PRS guitars) or recessed into the body on the opposite end of the neck (as with older Fender electric guitars and most brands of acoustics). The tool required will either be an allen (hex) key, a socket/nut driver, or a flat headed screw driver. Many brand new guitars come with this tool as part of the usual “case candy” from the factory.

To determine if your neck needs adjusting you can do two things. First, sight down the entire length of the neck from the nut to the bridge, along  the bass side of the fingerboard. What you’re looking for is any kind of bow or “hump.” If the neck appears fairly straight, you next view the neck from the side…fretting the 6^th string at the first and 15^th frets. This will turn the string into a straight edge between these two points. At approximately the 7^th fret there should be a small space between the string and the frets. This space is called “relief” and you need some if your guitar is to play and sound good! If this space is fairly excessive, the truss rod must be tightened (turn clockwise). If the string is touching the frets then the truss rod must be loosened (turn counter clockwise).

A bit of warning though…over adjusting can either damage your guitar or snap the rod off inside! If in doubt, be sure to have your instrument seen to be a qualified guitar tech.