Schertler A-Dyn-Set

Manufacturers of high-quality acoustic amplification solutions, Schertler offer a range of options suitable for acoustic guitar, including the new A-Dyn-Set, which comprises the A-Dyn contact microphone and A-Pre preamp.

Given the Swiss horological industry's pursuit of perfection (usually accompanied by reassuringly expensive prices), it shouldn't come as much of a surprise that a Swiss acoustic stringed instrument pickup manufacturer would share the same ethos.

Founded in the early 1980s by double bassist Stephan Schertler with the aim of reaching perfection in the reproduction of the sound of acoustic stringed instruments (and of finding the perfect pickup for his bass), the Schertler company nowadays produce some of the most unique and innovative transducers and associated preamplifiers available. In more recent years, Schertler have also expanded their interests into amplification, bass and cello strings, and even experimented with their own line of guitars. All Schertler pickups are designed and manufactured in Switzerland, and the 20-odd years of research and development that has gone into their development has also resulted in numerous patents.

Although Schertler amplifiers have enjoyed a low but nevertheless significant profile in the UK, their pickup systems have been all but invisible — apart, that is, from occasional appearances as OEM fitments in instruments from one or two manufacturers. That situation is now set to change, as Schertler have split their distribution across three companies: one specialising in recording applications, one addressing the classical market, and (the one that should affect us the most) Oswestry's Systems Workshop, who are tasked with looking after the live sound market. With these three companies working in tandem, I'd be hoping that Schertler's pickup profile will attain mainstream visibility.

Although their Bluestick undersaddle electrostatic condenser mic pickup system is perhaps the most unusual of their range, Schertler's most physically distinctive pickup range has to be their Dyn series of electrodynamic transducers. A Dyn transducer consists of a coil and a magnet, and is essentially a moving-coil dynamic microphone encapsulated in a circular housing that can be mounted on the body of an acoustic instrument and that picks up vibrations directly from the instrument. Schertler's original Dyn transducer line-up comprises of no less than 10 different units, whose frequency responses are tailored specifically to the instruments that they were intended to fit, from grand piano through orchestral strings, dobros, steel and classical guitars and the like. In addition, there is also a mind-boggling range of combinations and variants, with and without preamps.

The A-Dyn-Set includes cable supports (for violin, cello and double bass), floor clips for supporting the A-Pre, and putty for attaching the pickup to your instrument.

To help rescue us poor acoustic musicians from this miasma of moving-coil transducers, Schertler recently introduced the A-Dyn transducer and its custom preamplifier, which is capable of doing the job of any one of its 10 predecessors on any acoustic stringed instrument, albeit at some considerable damage to your wallet. The A-Dyn-Set (as the pickup/preamp combination in its trademark black Schertler wooden box is snappily named) is finished in a very fetching shade of metallic dark blue with white legending, and its looks certainly go some way towards justifying its price tag. The transducer itself follows the basic Schertler Dyn paradigm, but in this case the A-Dyn utilises a smaller, more powerful magnet that weighs in at seven percent of the weight of a corresponding magnet in the original Dyn transducer design. Although this new magnet gives an output some 8dB lower than its predecessor, it gives the A-Dyn a better low-end response and a flatter overall response than the original Dyn transducers, and also significantly reduces the size and weight of the transducer element itself.

The transducer element is decoupled from the outside world by a silicon 'spring' and its movement is air damped. This arrangement forms a mechanical 2nd order Butterworth filter with a Q of 0.6, which means, to you and me, that we get a flat response in the pass band (20Hz to 18kHz) and a gentle -12dB-per-octave roll-off below and above these frequencies. Being a dynamic transducer, we also get very high dynamic range (typically around the 142dB point), which will give a clean output on any stringed instrument that I can think of. As befits a low-impedance unit, the A-Dyn's output connector is on an XLR that can be connected directly to a mixing console or to an acoustic amplifier with an XLR output. However, Schertler also supply as part of the A-Dyn-Set the matching A-Pre preamplifier, and recommend its use for optimum results.

Featuring an XLR 'in' at one end and an XLR 'out' at the other, the cylindrical, phantom-powered A-Pre carries only three controls: a phase control to compensate for phase differences due to the distance between A-Dyn and amplifier; a three-position, low-frequency roll-off filter (flat, 100Hz and 200Hz); and a three-position gain switch (0dB, +8dB, +16dB). The audio specifications of the A-Pre are exemplary, with a frequency response of 16Hz to 50kHz and a Total Harmonic Distortion of only 0.005 percent — impressive to say the least.

Completing the contents of the box that carries the A-Dyn-Set is a little tub of a green putty-like material, which attaches the pickup to your instrument, and a set of clear plastic accessories — cable supports for violin, cello and double bass, and a couple of clips to stop the A-Pre from rolling around on the floor. Personally, I'd have traded the floor clips for a belt clip, but I guess that you can always just loop the cable through your belt in time-honoured fashion.

Fitting the A-Dyn to your chosen instrument takes you straight back to junior school. The first thing you do is take an 8mm-diameter ball of the green putty and roll it out on a flat surface to form a 'worm' around 6cm long. You then place this worm in a complete ring around the centre of the bottom of the A-Dyn and gently press the whole thing onto the appropriate location on your instrument until you feel the bottom of the transducer touch the soundboard, gently twisting as you do so to expel some air, thus creating a slight vacuum.

As with all transducers that get their input from being placed on the front of an acoustic instrument, the single most important factor in obtaining a great sound is location, location, location. A soundboard transducer like the A-Dyn acts pretty much like a stethoscope, and you'll need to invest some time and effort in determining the best place to put it on your particular instrument. Invariably, especially on good instruments, I've found that this is anywhere but where the manufacturer recommends and you'll need to experiment until you find the best place. To give you an example, Chris Thile of Nickel Creek (arguably the most visible Schertler Dyn user of recent years) fitted his Dyn-M behind the bridge on the bass side of his mandolin, which coincidentally is where Ry Cooder used to mount his Barcus-Berry pickup some 30 years ago.

I tried the A-Dyn on both my Mike Vanden mandolin and on my venerable Gurian S3 acoustic guitar, and got very good results with both after a couple of hours of positional experimentation. The Schertler putty is non-mar, leaves no trace, and so I could move and re-move the A-Dyn to my heart's content. Finding the best spot on an instrument for a soundboard transducer is a combination of careful listening to the instrument at very close quarters and then using the transducer like a stethoscope until you finally manage to convince yourself that the last millimetre or so is really not making that much difference — at which point you stop and weld everything in place.

Despite careful placing and its price tag, I can't say that the A-Dyn sounds like an equivalently priced microphone, and neither does it sound like the piezo pickup/microphone combinations that already reside in the two instruments in question. The A-Dyn has a pretty neutral character, and after a bit of experimentation with the phase and roll-off switches and final miniscule placement adjustments of the transducer itself, I got a good, pretty accurate and natural sound characterised by an effortless handling of the instrument's dynamics.

Using my Jam 400 acoustic combo amplifier (coincidentally manufactured by the Schertler associate company SR Technology) and comparing the A-Dyn side by side with the existing setups in both instruments, I ended up being very impressed indeed with this new Schertler transducer system. The way that the A-Dyn responds to the subtleties of a good acoustic instrument's dynamics is pretty breathtaking when your reference is a solo piezo pickup, and it is only the fact that I've got a fairly high investment in good pickups, microphones and high-end rackmount preamps that has kept me (so far) from splashing out on an A-Dyn-Set

Assuming that you've got a good instrument and that you've put the effort into finding the right spot to attach your new A-Dyn, there's only one question that you need to answer: is it worth the asking price? That's a hard question to answer indeed. Personally, if I had just one stage instrument that I didn't want to drill holes in and I had to have a high-end pickup system to fit to it, my answer would be an unequivocal yes. However, with my usual selection of three to four instruments on stage at every gig, I'd find it hard to spend the amount of money required to outfit them all, given the amount of investment that I have in my existing systems.

Mind you, the thought of downsizing the overall size of my rig by disposing of my racks is extremely tempting and I'll have to give that route some serious thought. In the meantime, I'll just dream a bit and try to hang onto the review model for as long as possible while I try to make up my mind. While I'm prevaricating, you could be experimenting for yourself. An A-Dyn-Set isn't an impulse buy and you'll have to be pretty sure that it suits you, your instrument and your PA/amplification system before splashing out that kind of money. If I were you, I'd be getting in touch with Systems Workshop to find my local dealer and be off down there to give the A-Dyn-Set an audition. It might just get the part. 0

Schertler A-Dyn-Set

Acoustic instrument pickup