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VSL Synchron Strings Pro & Synchron Percussion

Sample Libraries By Dave Stewart
Published May 2021

Vienna Symphonic Library Synchron Strings Pro & Synchron Percussion

The Vienna samplemeisters expand their Synchron orchestral range.

For VSL, 2020 was something of a Viennese whirl. After the successful launch of the free Big Bang Orchestra in Autumn 2019, the company ploughed their way through a galactic alphabet of 26 themed libraries featuring a 70‑piece orchestra, 48 singers and six percussionists. These inexpensive, colourful pre‑orchestrated starter editions were a welcome distraction from earthbound troubles in a difficult year, giving new users an opportunity to dip into VSL’s vast sample universe at entry‑level prices.

During this period, long‑time Vienna users were excited to see the expansion of the company’s pro‑level Synchron series, the most recent entry being Synchron Strings Pro. We’ll take a detailed look at that library and its predecessor here, and also give you an overview of the two Synchron orchestral percussion titles issued to date.

These sample collections run exclusively on the free Vienna Synchron Player, which works standalone on your desktop and as a plug‑in in your DAW. Capable of handling surround sound formats up to 9.1, VSL’s proprietary player software replaces the Vienna Instruments player — and before you ask, the prospect of a Kontakt version is about as remote as Katie Price marrying Jacob Rees‑Mogg.

Synchron Strings Pro

Following the release of Synchron Strings I, VSL enthusiasts might have expected a second companion volume featuring muted con sordino versions of the articulations, as was the case with several of the company’s earlier string libraries. That never happened: the new Synchron Strings Pro collection supplies a newly recorded set of articulations which augment and extend those supplied in the first library. As yet no sordino samples have surfaced, but given VSL’s commitment to that mellow and evocative timbre, I’d be surprised if they don’t provide them at some point.

Synchron Strings Pro (SSP for short) was performed by musicians from the Synchron Stage Orchestra in the building formerly known as Synchronhalle, now transformed by VSL into a state‑of‑the‑art recording facility. Fourteen first violins, 10 second violins, eight violas, eight cellos and six double basses were conducted by Johannes Vogel, with each section separately recorded from multiple positions using 13 microphones. The Standard Library requires 122.7GB of disk space and the Full version 237.8GB (more details in box below).

In addition to the new articulations, a few performance styles are taken from Synchron Strings I. Users of that library are offered a crossgrade price for the new library, while a comparison chart on VSL’s website makes it clear what articulations are included in both libraries. To save Synchron Strings I users the bother of downloading samples they already own, VSL have created an ‘optimised content’ version of the library which removes the redundant articulations incorporated in SSP, thus saving space on your hard drive.

The Vienna Synchron Player’s ‘Dimension Tree’ switching system shows all available playing styles for an instrument.The Vienna Synchron Player’s ‘Dimension Tree’ switching system shows all available playing styles for an instrument.

Artic Elation

A welcome feature of SSP is that articulations are identical across its five string sections, making it quick and easy to get to grips with the performances. Another advantage are ‘tutti’ presets which give access to the entire string orchestra over a full seven‑octave B0‑D7 range, with the sections artfully overlapped so that you can’t hear the joins — a boon for two‑handed keyboard players like myself. It gets better: you can opt to control dynamics with velocity rather than the mod wheel, thus freeing up the left hand for its natural biological function of performing bass lines.

I mainly used a tutti full‑range preset to audition the instruments, and was knocked out by what I heard. Short notes sound tremendous across the whole range, ranging from emotional one‑second detachés and all‑purpose regular staccatos to short staccatos which will propel rhythmic passages. While the fortissimo staccato patches sound quite harsh, quieter staccato deliveries have a lovely, full‑sounding brushed quality and a magisterial tone which is apparent even in their emphatic, businesslike bowing. For composers operating in the overworked ‘cinematic’ genre, the cream of the crop is the newly minted spiccato articulation: played shorter than the staccatos, energetic and spirited, it adds a sharp focal point to SSP’s armoury.

The Synchron Player’s suite of effects includes a convolution reverb based on VSL’s MIR Pro technology.The Synchron Player’s suite of effects includes a convolution reverb based on VSL’s MIR Pro technology.This large string ensemble’s beautiful tone reaches full bloom in the long sustains, which are technically and musically perfect. You can crossfade on the fly between conventional vibrato, expressive ‘molto’ and no‑vibrato styles, or dial up the sighing soft attack patch for a romantic ballad. A marcato attack option (which sounds like a programmed layer) adds strong definition to long‑note passages and would help string pads to hold their own against a rock rhythm section. VSL’s aggressive sforzatissimo style is not included, but if things turn nasty you can always dial up the insanely forceful and arresting ‘Bartok snap pizzicato’ articulation, played here with maniacal intensity.

By contrast, SSP’s standard plucked pizzicato style is pleasant and mellifluous, an ideal timbre for a children’s TV theme. The col legno hits are a bit feeble; I can’t believe this healthy band of players couldn’t muster more welly when hitting their strings with the back of the bow. A workmanlike set of played crescendos and diminuendos does what it says on the tin, or you can easily create your own dramatic long‑note surges and fades by engaging the mod wheel.

Tremolo & Legato

Though there are no played runs or phrases, this library contains some handy performance samples: ‘measured tremolos’ are exciting, back‑and‑forth 16th‑note bowings originally played at 130bpm which were doctored to create convincing 120, 140 and 160 bpm variants. You can further customise these performances’ tempo by using the Synchron Player’s time‑stretching feature. An interesting, rarely used style is tremolo harmonics, a wispy, spooky articulation which generates strange little high frequencies reminiscent of alien radio signals in the background. Meanwhile, semitone and whole tone trills generate their usual stirring, shimmering soundscapes.

You can use the Synchron Player’s built‑in time‑stretch feature to edit performance tempos, the speed of portamento pitch slides, and so on.You can use the Synchron Player’s built‑in time‑stretch feature to edit performance tempos, the speed of portamento pitch slides, and so on.

Since its invention by VSL back in the day, the revolutionary, interval‑specific legato note transition system has been widely adopted throughout the industry. Designed to smooth out melody lines, the original Vienna legato patches were monophonic, but in recent years the company added a polyphonic mode which has now become the default legato setting. If you prefer the old monophonic mode, you can simply re‑select it.

VSL used a new recording method for SSP’s legatos: rather than performing single‑interval movements starting on each note of their instrument, the musicians played longer phrases from which the makers extracted the requisite interval transition samples. The end result is excellent: you can choose between ‘bold’ and ‘agile’ attack variants (the latter of which is optimised for fast runs), or select the ‘auto‑speed’ setting which switches automatically between the two according to your playing speed. Either way, melody notes sound fluid and convincingly joined‑up.

Portamento pitch slides are another welcome addition: these can be used to insert small swoops between notes, or less subtly to emulate the exuberantly gliding Bollywood string style. Glide speed can be altered with the time‑stretch function. If you study Guy Bacos’ video demo of these legato articulations, you’ll see how he instantly switches between straight legato and portamento slides on the fly, often inserting a slide for a single quick passing note. Hats off to Mr Bacos for his endless stream of imaginative VSL‑powered compositions, and big kudos to the musicians, producers, engineers and programmers who created this superb strings library.

Synchron Percussion I

Rewinding the clock a few years, VSL’s debut Synchron Stage release was the 406GB Synchron Percussion I, featuring 16 essential percussion instruments and drums. This was the first Vienna orchestral library to be recorded outside of the company’s Silent Stage studio, and the first to feature multiple mic positions. Synchron Percussion II (341.6GB) followed in 2020. The full contents are listed on VSL’s website; here’s an overview which pulls out a few personal highlights.

Synchron Percussion I contains 16 essential orchestral percussion instruments divided into six categories.Synchron Percussion I contains 16 essential orchestral percussion instruments divided into six categories.

Synchron Percussion I’s timpani preset uses nearly 50,000 samples (a record for that instrument?). The timps’ powerful, ringing ultra‑clean strikes include excellent dynamic rolls and some nice boingy glissando pitch‑bends. The Kolberg 36‑inch orchestral bass drum delivers a classic, skin‑flapping big wallop, and also provides fabulous soft beater hits, useful single and multiple upbeats and a great set of thunderous rolls.

Though crisply recorded, the library’s snare drum is not the most commanding I’ve heard, but you could use its brush hits for jazz if you solo the close mics. For those seeking battering rock sonorities, I can recommend the library’s eight Yamaha concert toms, which sound positively explosive when harnessed to the ‘Comp‑Boom‑Saturation‑Reverb’ mixer preset. The Djent‑friendly Meinl Heavy piatti cymbals also make a decent melodramatic splash, while an extra‑large tam‑tam contributes awe‑inspiring, roaring dynamic rolls. In a more insinuating vein, the cymbals and gongs also provide the atmospheric scrapes, swishes, screeches and superball‑induced groans needed for horror soundtracks.

The tuned percussion department is distinguished by a twinkling glockenspiel and an impeccably sampled xylophone, with the latter’s leather beater hits providing a nice melodious attack. Despite a tremendous deep sampling job the celeste didn’t immediately win me over, but after some judicious mic rebalancing and EQing I managed to attain the magical sparkle I associate with the instrument. A nice set of wood blocks and ethereal, ear‑catching triangles are also included, along with some cool shaker patterns which you can use to program light Brazilian grooves.

VSL’s large percussion collection pictured at the Synchron Stage. Imagine trying to get that lot in the back of your car!VSL’s large percussion collection pictured at the Synchron Stage. Imagine trying to get that lot in the back of your car!

Synchron Percussion II

Clocking in at 341.6GB, the second Synchron Percussion collection adds new instruments to each category. Timpani soft mallet performances offer a nice, doomy‑sounding alternative, with two‑drum octave hits sounding good and strong. A smaller Lefima orchestral bass drum combines a clean attack with a big, forceful low end and all the performance variations you might possibly want, accompanied by a fine array of combative taikos. If you’re a fan of epic low drums, some of the mixer presets’ EQ and compression treatments will raise the roof (and possibly destroy the rest of the building into the bargain), but a set of six Rototoms adds a lighter touch.

Synchron Percussion II adds extra instruments.Synchron Percussion II adds extra instruments.

SPII’s metals turn to the East for inspiration — to China, where a 70cm tam‑tam gong contributes some big, auspicious hits and ominous rubbed superball effects, and to Burma, ancestral home of a four‑octave chromatic set of tuned gongs. The latter’s quaint chime could pass for an English Edwardian dinner gong, but when played softly in the upper register, these small gongs create an intriguing, delicate and unusual bell‑like timbre.

A chromatic five‑octave set of plate bells are another ear‑grabbing texture. I found that adding modulation and a long reverb to their straight hits creates an entrancing otherworldy chime, while the bowed effects sounded amazing. I also loved this library’s vibraphone. Sampled with and without its iconic tremolo effect, its pure, floating tones are a delight, and the bowed samples are a great, Radiophonic‑style sci‑fi texture. A two‑octave set of crotales (tuned mini‑cymbals) also make a lovely, clean and penetrating ethereal sound.

The library bows out with a large miscellany of unpitched percussion. Among the more useful items are a rainmaker whose slow delicate trickle would work well in an Amazonian nature documentary soundtrack, and some nice, distinctly pitched log‑drum hits. I can also reveal that the ‘Lion’s Roar’ is a large cuica‑like drum which produces a monotonous bassy groan, and that the Waldteufel (literally, ‘forest devil’) emits frog‑like croaks reminiscent of a detuned guiro. Good names for a pub quiz question?

The libraries uphold the high standards set by this pioneering outfit since 2000, giving professional users the tools required to create detailed, dynamic and expressive orchestral arrangements.


If you want to run simultaneous multiple mic positions, these libraries will test the limits of your system — one Synchron Strings Pro tutti preset I auditioned contained over a quarter of a million samples! Consequently, VSL’s minimum system requirements stipulate an SSD drive for the sample content, without which these massive instruments will fall over. You’ll also need a minimum 16GB of RAM (32GB is recommended).

Some users have complained of excessively long install times as the Synchron Library Installer converts the downloaded files into playable instruments. VSL say that the hard drive is usually the bottleneck, and warn against using ExFat‑formatted drives — apparently Mac OS extended (Journaled), HFS+, APFS and NTFS formats are OK. In such circumstances, the company also suggest that users turn off their anti‑virus software during installation.

Technical caveats aside, I can wholeheartedly recommend VSL’s Synchron strings and percussion collections. The libraries uphold the high standards set by this pioneering outfit since 2000, giving professional users the tools required to create detailed, dynamic and expressive orchestral arrangements. If you’re wondering how they stack up against the older Vienna Instruments libraries, I’d say that the Synchron Stage hall acoustic adds a vital aura, resonance and sense of size which was absent in the Silent Stage samples, giving the percussion in particular much‑needed extra force.

The Big Bang series saw VSL shake off their academic image and connect with contemporary users, while the deep‑sampled Synchron collections maintain links with the classical world. All the musical detail, performing expertise, engineering experience and programming skills one might hope for are faithfully represented, showing a company at the top of its game. Combining beauty, subtlety and power, these are orchestral samples for all seasons.

Synchron Strings I

Back in the carefree days before plague, pestilence and pandemics walked the Earth, VSL announced the first strings library recorded in their newly refurbished Synchron scoring stage. Featuring the same line‑up as its sequel Synchron Strings Pro, Synchron Strings I set out its stall with a full complement of articulations including long and short notes, a versatile set of legatos, delicate flautando sustains and an uplifting ‘cantabile’ (singing) melodic style for violins, violas and cellos played in a choice of strong and light vibrato. This large library’s standard version is 255.7GB installed, while the full version is a whopping 505.3GB. Order those hard drives now, folks!

A notable feature of this collection (which also accounts for its large size) is that it utilises considerably more velocity layers than Synchron Strings Pro. For example, the short staccato artic has eight velocity layers in Synchron Strings I, but only five in the Pro library. A VSL spokesman explains: “We tried to streamline Synchron Strings Pro in terms of performance, CPU usage and RAM space to make it easier to work with. While it seems counter‑intuitive that the Pro version has fewer velocities, it reflects the fact that professional composers want to work quickly without a lot of overhead, while enthusiasts who have more time on their hands to tweak samples will ask for more variations in their libraries. Workflow and ease of use was therefore one of the priorities when developing Synchron Strings Pro.”

Standard vs Full Microphone Positions

VSL’s Synchron range maintains the company’s two‑tier system of a lower‑cost Standard version and a more expensive Full library. Formerly it was common for standard libraries to omit the fancier performance styles found in the full version, but in the Synchron range articulations remain the same in both versions: the difference lies in the number of provided microphone positions.

The Standard libraries of the titles covered in this review include the following mic positions:

  • Close Mic (mono)
  • Mid Mic — Front row of ensemble (L/R)
  • Main/Room Mic — Decca Tree Stereo (L/R)
  • Main/Room Mic — Decca Tree Mono (Centre)

The strings’ Standard version has an extra ‘Back Mic — Second row of Ensemble (L/R)’ position. All of the products’ Full libraries contain these additional positions:

  • Main Surround — Stereo (L/R)
  • High Stereo (3D) — Stereo (L/R)
  • High Surround (3D) — Stereo (L/R)

Under VSL’s articulation‑based sales structure, a user might end up having to buy an entire full library merely in order to add one vital style to an arrangement. This system seems fairer: the standard mikings provide all the options one might need for a stereo mix, while composers who habitually create surround stems for cinematic productions will (one hopes) be paid well enough to cover the extra cost of the Full libraries.


  • Synchron Strings Pro combines a beautifully lush strings sound with superbly accurate performances.
  • The strings’ comprehensive articulation menu is identical for each section.
  • Programmed full‑range tutti presets and premier‑league legatos make the instruments a dream to play.
  • The deeply sampled Synchron Percussion libraries benefit hugely from the hall acoustic.
  • All libraries were recorded from multiple mic positions in a state‑of‑the‑art sound stage.


  • To run these libraries you’ll need a SSD sample drive and plenty of RAM.
  • The full collections are pricey.


VSL’s ever‑expanding Synchron range hits the jackpot with Synchron Strings Pro, featuring 46 string players creating a beautiful ensemble sound while absolutely nailing their performances. The powerful Synchron orchestral percussion libraries are also first‑class. Recommended for all those engaged in serious, pro‑level orchestral programming and composition, whether it be for a big‑budget movie or a price comparison website TV ad.


Synchron Strings Pro Standard Library €445, Full Library €740; Synchron Strings I Standard Library €445, Full Library €740; Synchron Percussion I Standard Library €495, Full Library €890; Synchron Percussion II Standard Library €495, Full Library €890. Prices include VAT.

Synchron Strings Pro Standard Library €445, Full Library €740;Synchron Strings I Standard Library €445, Full Library €740; Synchron Percussion I Standard Library €495, Full Library €890; Synchron Percussion II Standard Library €495, Full Library €890. Prices include VAT.