Your Amplified Violin Not Working with Effects Processors?: The Problem is With Your Pickup! (Don Rickert Musician Shop)
This is an update of an article published in 2015.
Many violinists with an “amplifier-ready” (i.e. has a pickup) instrument try to use effect processors to extend their sound palate. Effect processors are usually called “guitar effect boxes”, because such devices have historically been marketed to electric guitarists. In recent years, there has been a growing number of effect processors marketed for use with amplified acoustic guitars. Such devices are often referred to by their nickname, “stomp box” (referring to the way they are activated, by stomping on a switch with one’s foot). Many amplifiers come with a selection of common effects built into the amplifier housing.
Widespread Mistaken Beliefs
Study of a large number of discussion threads on online violin and fiddle special interest websites reveals that there is a lot of misinformation about violins and effect signal processors on the web. Widespread wrong information on the web?...say it ain’t so! Here are a few:
- Most effect processors do not work with violins.
- A bowed note is different from a plucked not and, therefore, somehow does not “track” with many effect processors.
- All guitars, regardless of their pickups, do work with most effect processors.
Hopefully, this article can dispel these mistaken beliefs and set you on your way towards using just about any effect signal processor with your violin. Warning: You may have to get another violin. This may be the first time that many of you would have to spend serious money in furtherance of your art. We know that it is virtually a part of the fiddlers’ unofficial creed that one should not have to spend money on just about anything. This includes decent strings, tuning pegs that work, good bows or even a quality instrument.
The Classic Effects
These are effects that have been around in one form or another since the 1960s and, in some cases, even longer. They include things like tremolo, reverb, delay, compressors, limiters, overdrive, distortion, echo and basic chorus. The main difference between effects of this sort made 50 years ago and those made today is that the newer ones are more electronically sophisticated and work better. In fact, the earliest echo and reverb units were completely electro-mechanical in nature and prone to mechanical failure (e.g. broken echo unit loop tape or disconnected reverb unit spring)
What the classic effects have in common is that they do not do any heavy duty signal processing that require the processor to accurately detect the frequencies that comprise the input signal. These old school processors will take just about any signal thrown at them, including human voices via microphones, and do whatever it is they are designed to do.
The Classic Effects and Violins
These effects, needless to say, work flawlessly with guitars with just about any kind of pickup(s). Further, I know of no situation where a violin, whether it be an acoustic violin with a pickup or an electric violin (even the cheap ones), has failed to work with any of the “classic” effect processors.
Unfortunately, these effects that DO work with most violins are NOT, with some notable exceptions (e.g. Eileen Ivers' artful use of distortion and a wah-wah peddle), of much interest to violinists and fiddlers. Really, does a violinist really need a "sustain" effect or a desire for distortion.
The Problematic Effects
The Problematic Effects are those that many violinists desire. We call them the “Cool Effects”. They are also the ones that DO NOT work with most violins. Included in this group of effect processors are:
- Octave converters (generate notes 1 or even 2 octaves lower than the unprocessed signal)
- Pitch shifters
- Detuners (aka “anti-chorus”; by mixing a processor generated note that is slightly pitch-shifted with the original note, simulates two violins playing in unison)
- Exotic effects, such as an effect that generates the sound of sympathetic strings (can make a violin sound like a viola d’amore or a Hardanger fiddle)
What do these “problematic” effects have in common?
All of the effects mentioned above, and ones similar to them (e.g. overtone generators; sub-harmonic generators, etc.) involve heavy-duty signal processing. It is essential that these signal processors determine, in near real time, the fundamental of each and every tone in a signal. Put another way (and anthropomorphizing a bit), the signal processor needs to “know” exactly which notes it is dealing with…and really fast (a millisecond at most).
Why these effects are a problem for violins
Violins and guitars have this in common: the tones (notes) they generate are NOT a single frequency. Rather, they generate notes that are comprised of a fundamental (the note that is perceived by a human), together with a large number of overtones, which are called “harmonics”. A fundamental and its set of associated harmonics is called a “frequency spectrum.” The human brain is really quite amazing its ability to organize the apparent chaos of a frequency spectrum, allowing a person to perceive a single note. A number of people have deficits in their ability to process and organize auditory stimuli and are, thus, very disturbed by sounds, especially music.
A simplified ideal frequency spectrum for a single violin note, as perceived by a average human, is shown below.
Note that sub-harmonics (harmonics with lower frequencies than the fundamental) are not shown in the example graphs for the sake of simplicity.
Electric guitars that are set to “flat” (EQ set to neutral for all bands) and the tips of violin bridges (where the strings contact the bridge) produce well-organized frequency spectra where the fundamentals have the highest amplitude (volume), which is usually measured in decibels (dBs).
The following idealized frequency spectrum graph illustrates this:
A frequency spectrum graph of the sound emanating from a violin top is not even close to a graph based on measurement from the bridge tip. See the illustration below, which shows (using the color red) the points at which the overtones actually have higher amplitude than the fundamental.
The following illustration attempts to convey the magnitude of the difference from what is recorded from a violin top and what is measured from its bridge tip.
It is noteworthy that all of the above frequency spectrum graphs are based on actual frequency spectrum graphs for a specific Stradivarius violin. So we can safely assume that instrument quality is not an issue here.
There is no way that a signal processor whose operation depends on “knowing” the note it is dealing with to do anything useful with such a frequency spectrum emanating from the soundboard (top) of a violin. Interestingly, as mentioned earlier, the human brain’s auditory processing system has no trouble reorganizing the apparent chaos captured in the above illustration into a sound that makes sense. In other words, what a human hears is closer to energy recorded from the violin bridge tip.
The next illustration shows the difference from a violin soundboard (top) frequency spectrum and what is ideal for a signal processor. The heavy blue line indicates the ideal.
So, Where Are We?
We know that, for any given note played, measurement of where violin strings contact the bridge yields a very different frequency spectrum graph than a graph based on the sound emanating from the instrument body, particularly its top. It is only the former (i.e. strings touching the bridge) that produces energy that can reliably and consistently be interpreted by certain signal processing devices (i.e. the cool but problematic ones).
All of what has been said appears to explain why effect signal processors work fine with electric guitars, but only with a minority of violins. With electric guitars, generating a signal is all about changes in electro-magnetic energy in response to string vibration. It is the vibrating strings interacting with powerful electro-magnetic pickups that produces the signal. This signal is at least predictable enough for effect processors to do their jobs.
This brings us to violin pickups.
A Brief Survey of Attempts to Make Violin Pickups
Buidling a Better Violin Pickup
Over at least the past 50 years, there have been countless attempts to invent violin pickups that actually work. Generally, there has been no major difference between pickups used on full-on electric violins and so-called acoustic-electric violins.
Curiously, while there have been attempts, magnetic violin pickups similar to those used on electric guitars have never caught on in any significant way.
Most magnetic pickups for violins, since the beginning and today, don’t sound very good (by any definition of the word), at least not without the help of industrial strength equalizer/preamps and other signal processing equipment. Even then, some still sound thin and tinny.
In any case, every attempt that I know of to bring a magnetic violin pickup to market has ended up being mostly rejected by players. An even larger impediment to adoption than sound quality is the fact that magnetic pickups require strings with ferrous (e.g. steel) core and windings. Only a minority of violin strings are made primarily of ferrous materials. Violin strings have cores either of some type of polymer fiber or a non-ferrous (i.e. NOT MAGNETIC) alloy. The windings are more likely to be aluminum, titanium or silver than steel.
Overwhelmingly, pickup designs have, over the years, involved piezoelectric elements that are...
- Stuck to the bridge
- Wedged in the bridge wings
- Stuck to the violin body
- Situated between the violin’s bridge and top plate
- Cheap violin under bridge pickup (worthless)
- High-quality under-the-bridge pickup (sounds pretty good)
- Embedded into the bridge
- Single transducer epoxied into a hole drilled or routed into a regular bridge (probably the most popular type used on acoustic violins)
- Multi-transducer a la Barbera Transducer Systems
- Other strange methods
- What looks like a tire inner tube wrapped around the instrument mid-section
- Small mic on a gooseneck attached to the tailpiece ... mic aimed at violin top, the bridge or, in some cases, at a sound hole.
Images for some of the pickups listed above (click on any of the thumbnails for larger views.)
The only pickups that work with the cool problematic effects with at least fairly consistent reliability are those with piezo transducers embedded in a wooden bridge. The most familiar names associated with these bridge pickups are L. Baggs, Fishman, Schatten and Barbera. Other less familiar names (but great pickups) are Aceto-Violect (Ithaca Strings) and Bradivarius (Brad Higgens).
The only pickups that we know will work reliably and consistently with any effect signal processor we have encountered virtually 100% of the time are those by Barbera Transducer Systems or a custom pickup that is based on the same theory of operation. In fact, we have installed the Barbera pickups on a number of instruments, including experimental violins designed specifically for driving effect signal processors. The pickups have worked flawlessly with octave, harmonizer, detuner, overtone generator and sub-harmonic generator effects (all commonly deemed to be impossible for violins!). We have been able to simulate a contra-bass with a Barbera augmented violin by taking it 2 octaves down and driving a 400 watt bass amp outputting to massive sub-woofer system. This worked without a glitch in an instrument design competition live performance.
Most of the other bridge pickups above will work very well; albeit, not with the near-100% reliability of a Barbera pickup, with the most sophisticated effect signal processors. Pickups that contact the tops of instruments in any way (notably, the otherwise very good pickups by by Realist) are not generally suitable for live performance when advanced effect processors are involved. It is only the pickups with transducers embedded in a bridge that have a fighting chance in an amplified live performance situations with the cool problematic effect processors.
Why the Barbera Pickups DO Work Well with Signal Processors
Barbera pickups are based on a theory of operation that is the opposite of the approach taken by some other pickup manufacturers. According to Barbera, placing a single large transducer between the bridge and the top plate (the approach used for the Realist pickups) results in what is called a surface sensitization effect; whereby the resonant surfaces of the instrument become microphonically active (i.e. the top of the violin becomes a microphone, in effect). This results in an unfocused signal, as there is very little selectivity in the way that the vibrational information is collected. This means that everything gets amplified, and the very reason why Realist and similar pickups are so highly-regarded for their "realistic" acoustic violin timbre when amplified--sounds like an acoustic violin, only louder!
Barbera, instead of putting a single transducer under the bridge, embeds 2 or 4 (depending on the model) piezo elements PER STRING near the part where the string contacts the bridge. For a 5-string, that is 10 or 20 transducer elements. As one would imagine, the signal from a Barbera pickup is quite focused, and it is. The output signal contains unambiguous fundamental frequencies (higher amplitudes than the overtones). This is exactly what many effects that simply do not work with most amplified violins require, especially octave changing and harmonizer effects. These "impossible" effects work flawlessly with a violin using a Barbera pickup.
- Paradoxically, while producing very strong and clear fundamental frequencies for effects boxes, the Barbera pickups do, in fact, interact substantially with the vibrating top of the instrument to produce rich harmonics. It sounds very focused and "clean" to the ear when amplified. It is up to debate whether amplified sound is quite “natural”. It is definitely not exactly the same timbre as the unamplified sound of the same violin when played acoustically.
- With the right combination of effects boxes, equalizers, amplifiers and signal routing switches, a violinist or fiddler can realistically reproduce a very natural amplified sound of a cello, double bass or even contra-bass (the lowest instrument in the bowed string family). The musician can also do things like add sympathetic string chordal accompaniment in any of the octaves.
The Right Pickup for an Acoustic Violin Depends on What the Player Will Be Demanding From It.
The most important considerations are the following:
- Live performance, recording session or something else?
- Size of venue: Are you going to be playing in a pub, a large auditorium or an arena?
- How loud? - Will you playing a sound-reinforced version of what is essentially an acoustic performance, or high-energy and high-volume (really loud!) performance, such as Celtic Punk (e.g. Flogging Molly, Drop Kick Murphies) or something in between?
- Desire for a very rich and "natural" acoustic violin sound without requiring too much sound engineer magic - Be aware that you cannot always get what you want. If you are playing a high-volume performance in an arena, forget about a natural acoustic sound without use of special effects for simulating such.
Rating every pickup on every dimension is way beyond the scope of this article; however, I will offer some general opinions to guide you. If you wish to discuss your particular needs, that is what we are for at D. Rickert Musical Instruments. The email address is email@example.com and the phone number is 404-828-0136.
Opinion 1: This is actually a rule. If you use ANY kind of piezo pickup, you MUST use a preamp designed for adjusting the signal impedance. Impedance is an extremely complex topic and my goal here not to bore you into a catatonic stupor, I will try to simplify. Impedance is essentially the degree to which an electrical signal is obstructed (i.e. impeded), so high impedance is not good. Impedance is usually expressed in Ohms. In general, paradoxically, the more powerful a pickup is, the higher its impedance. Piezo transducer pickup output impedance is always quite high.
The output impedance of a violin pickup can be up to 1 MOhm (that is 1,000,000 Ohms); whereas the typical amplifier works most effectively with something less than 4 KOhms (4000 Ohms) and a sound board (via DI box) NEEDS a signal of 4 KOhms at most. With an amplifier, NOT using a preamp will sound thin and lifeless. If plugging into a DI (i.e a "direct box"), it just will not work without an impedance-matching preamp. The good news is that impedance matching pre-amplifiers do not cost very much. You can get a really good mini preamp that clips onto your belt for $100 or less.
Opinion 2: If you are playing in a recording session and you do not require any of the cool effects discussed earlier, you are probably better off with using one or more high-end microphones used in recording studios and relying on recording engineer mojo.
Opinion 3: If you are going for a really natural violin/fiddle sound, and you are playing a sound-reinforced acoustic performance without effect processing in a small (e.g. pub, square or contra dance, wedding reception) to medium-sized (e.g. a 500 to 1000 sear auditorium), the Realist pickup, or better still, a Realist Pro Amplified Acoustic Violin is usually an ideal choice.
Opinion 4: If you play in any type of "plugged-in" band, the volume will most likely be high enough that feedback will be issue, any of the bridge pickups with embedded transducers mentioned earlier will work well. Further, with these pickups, some cool effect processing, such as as an octave converter, is possible.
Opinion 5: Regardless of the size of venue or the volume at which you will be playing, if you intend to make substantial use of the cool but problematic effects, you will need a Barbera pickup (or a full-on electric violin) in order to ensure reliable and consistent performance.
Opinion 6: If you have an acoustic violin with a Barbera pickup installed, you will want to designate it as a dedicated amplified performance instrument. Due to the mass of a Barbera pickup (about twice that of a normal bridge), the instrument will not sound as good when played acoustically.
Return to the Widespread Misinformed Beliefs Listed at the Beginning of This Article
Most effect processors do not work with violins.
Most effect processors DO work with properly equipped violins. Of the widely recognized top tier electric violins (Wood Violins, Jordan, Jensen, Vector, EVL Violins, Stratton, NS Design, Bridge, Yamaha and Fuse), the majority of these work perfectly with most effect signal processors. The best electric violins all use pickups that capture energy mostly from their bridge tips. It is not coincidental, that many of the top electric violins utilize Barbera pickups.
See the photo album on our Facebook page entitled Some of the Best Electric Violins.
Further, the several dozen acoustic violins and fiddles on which we have installed Barbera pickups, all have worked perfectly with any effect signal processor tried. All of the aforementioned pickups consisting of a bridge with embedded piezo transducer elements work well, as long as the overall volume in the room is not too high. What is too high is a bit of an unknown here; however, I can tell you with certainty that if feedback from the violin is a problem, there will also be problems with driving your effects.This gets us back to the Barbera pickups, which are the most feedback-resistant pickups made.
A bowed note is different from a plucked note and, therefore, somehow does not “track” with many effect processors.
Whether a note is bowed, or generated with a pick, has NOTHING to do with ability to function with effect signal processors. It is all about generating a signal comprised of frequency spectra with a dominant fundamentals (i.e. higher amplitude than the overtones).
All guitars, regardless of their pickups, do work with most effect processors.
We did not really cover this one. The fact is that all guitars do not work well with signal processors. There are older guitars with lousy pickups that fail to generate a signal compatible with effect processors. Further, most new “value priced” acoustic-electric guitars use under-saddle piezo transducers. These do not work any better with effect processors than under-bridge piezo transducers on violins.