Software Synthesizer

Published in SOS May 2011
Bookmark and Share

Reviews : Synthesizer

The original was a diamond in the rough — so is PolyKB II a highly polished gem?

Gordon Reid


in October 2010's SOS, I reviewed the original PolyKB soft synth from XILS Lab in France. This modelled analogue instrument was intended to recreate the rare, early '80s PolyKobol, created by French company RSF, and I complimented its sound and versatility, but also noted some bugs and unfinished ideas. Now here we are, less than a year later, and the company have released PolyKB II, which claims to address many of the points I raised, as well as enhancing numerous features and adding new ones. The excellent oscillators and filter have survived unmolested, but much of the rest of PolyKB has been improved, including the modulation matrices, X/Y and spatial modulators, arpeggiator, sequencer, the effects section, and the user interface. If you didn't see the original review, by the way, my comments will make more sense if you read it first, at /sos/oct10/articles/xils-lab-polykb.htm

What's New?

PolyKB II showing the zoomed‑in sequencer page.PolyKB II showing the zoomed‑in sequencer page.

Let's start with the GUI. That of the original PolyKB was dim and overshadowed in places, so I'm delighted to report that the PolyKB II interface is a big step forward. Although it contains more controls and more options than before, everything is brighter and clearer. There are three display options, the smallest of which will be particularly good for users with older, lo‑res monitors. On my Mac, Digital Performer 7.22 displays all three correctly, but only the largest is displayed in Plogue Bidule, so you might want to check that all is well on your system before purchase.

Moving on, let's turn to the Modulations section in the centre of the panel. If you look at the switches here, you'll see that red/green 'LED' pairs have replaced the single on/off indicators of PolyKB. Press a button once to link a source to a destination and the red light comes on; the source is now connected with negative polarity. Press it again, the green light comes on and it's connected with positive polarity. While I would have reversed the order (positive first and then negative) I'm not going to criticise, because this answers one of my major concerns regarding the original PolyKB: that velocity sensitivity could only be applied positively, so, for example, a higher velocity meant that, while your filter cutoff frequency went up, your contour times were extended and the response slowed down.

If you look even more closely at the Modulations panel, you'll also see a small icon above the velocity VCA button. This is shown as either [+] or [x] and allows you to determine whether the MIDI velocity is added to, or used as a multiplier for, the VCA value. I like this. Other improvements in this section include a couple of additional modulation destinations, plus the mono‑mod LFOs promised when PolyKB first appeared.

The most creative enhancements to the modulation facilities lie in the 'Programmation' section that houses the X/Y modulation, spatial modulation, sequencer and arpeggiator. In my original review, I commented that it would be great if the voice positions in the X/Y modulation page (now called PolyMYX) could themselves be the destinations of other modulators, and that they needed to be bipolar (a position one side or the other of an axis could increase the value of one parameter while decreasing the value of another). Well... the bad news is that the positions are still not destinations; the good is that they are now bipolar, as are the positions in the renamed DynaMYX spatial modulation window.

There are two new, spatial modulation modes in DynaMYX: Aquarium and Magnet. When the first of these is chosen, the voices swim around in the 'room', while the second causes them to respond as if they are all attracted to or repelled from one another. You can control the amount and speed of movement in either mode, as well as the degree of phase shift that occurs as the voices move about in the virtual space. However, the propagation delays, reverberation and pitch shifting that would occur in a real space are not calculated, no doubt because to do so for multiple voices in real time would require significantly more computing power than even the fastest CPUs can yet provide.

The arpeggiator has had its bugs ironed out and has been enhanced, boasting its own programming window. This adds the option to choose an octave range, a poly mode, swing, chord arpeggiation and more. It's now a powerful system with many more creative possibilities than before. Likewise, the sequencer has been enhanced with improved controls and a larger display that appears in the centre of the GUI if you click on the magnifying-glass icon. You can use the arpeggiator and sequencer together to create some fascinating, complex patterns, but you'll have to work at this to create useful results, or be lucky enough to stumble across something musically meaningful.

Finally, PolyKB II boasts two new effects: a phaser and a parametric EQ. I'm delighted that the first of these has been added, although, to be fair, it doesn't emulate the deep swish of vintage stomp boxes. Nonetheless, it's very flexible and you can enhance its effect greatly using the two‑band (low/high) EQ, which is also a welcome addition.

In Use


PolyKB II feels more polished than its predecessor. Numerous niggles have been corrected, and serious imperfections such as the omission in the key tracking (which previously affected only the Attack stages of the envelopes) have been corrected, making it a much better synth than before.

Of course, it's not perfect, and I'm mildly disappointed by the lack of a unison detune knob, and concerned by an occasional propensity for inserting small glitches at the starts or ends of notes, especially when the system is stressed by the use of unison and the X/Y effects pages. There are also small graphical anomalies when the larger sequencer window is displayed. But notwithstanding this, it has become a very fine soft-synth, warm and engaging, and it simply sounds nicer than most of its competitors.

Another bonus is the fact that PolyKB II is a free upgrade for existing users and can be run using the same licence as the earlier version. What's more, it will load and use PolyKB patches, although there will, of course, be small differences, particularly in the area of modulation. Interestingly, if you have installed PolyKB II as an upgrade, you can run both versions simultaneously, as well as the forthcoming PolyKB II Player (see box). This means that you can retain the use of your PolyKB patches without any changes, while reaping the benefits of PolyKB II. One of the major pitfalls of upgrading — "sure, it's better overall, but I've lost such‑and‑such, which is a real pain...” — is not an issue. Bravo!


At the end of my PolyKB review I wrote that, "once the bugs have been zapped and all the features are finished, I expect it [PolyKB] to be one of my favourite soft synths”. Well... the bugs have been zapped and the features are finished, so if you're thinking of buying a soft synth that emulates a vintage polysynth, I strongly recommend that you evaluate PolyKB II.  

Sound Bags

XILS Lab have released two libraries of sounds to complement PolyKB II. Bag 1 ($23) concentrates on exotic pads and effects, and provides an interesting opportunity for users to see how things can do things to other things within PolyKB II. Bag 2 ($28) offers more patches and a wider palette of slightly more conservative, and therefore more immediately useful, sounds. If you're looking for something to get you started or are stuck in a bit of a rut, these may be worth trying.

The PolyKB Player

XILS Lab have pre‑announced a patch player for people who want to access the sounds of PolyKB II but don't want to programme it in depth. It was still in development while this review was being written. Based on the PolyKB II synth engine (and therefore not available as a stand‑alone player), it will retain the arpeggiator and effects, and allow users to control up to eight automatable parameters per patch. The player will be supplied with the PolyKB II's factory sounds and will also import XILS Lab's sound sets, including the recently released Sound Bags. Its projected price is $35, and an upgrade path from the Player to PolyKB II is promised.

XILS Lab PolyKB II €149$199
It's a great-sounding soft synth.
It boasts a significantly improved graphical user interface.
There are major improvements in the modulation sections.
There are improvements in the arpeggiator and sequencer.
There are two new effects.
Most, if not all, of PolyKB's bugs and omissions are now history.
There's still no stand‑alone version.
It glitches occasionally.
I liked PolyKB very much. I like PolyKB II even more. If you're looking for a soft synth that emulates a vintage analogue synth but goes a step (or three) further, try the free demo version. I'll be very surprised if you don't like it too.
€149, or free upgrade for PolyKB I users.
$199, or free upgrade for PolyKB I users.
Test Spec
Apple MacBook Pro 2.6GHz Intel Core 2 Duo with 4GB RAM and Mac OS 10.6.6.
Plogue Bidule v0.9708.
MOTU Digital Performer v7.22.

SOS Readers Ads


of Second-User Gear for sale now — don't miss out!

Roland GR55

Guitar Synthesizer

Thumbnail for article: Roland GR55

Roland have put elements of their two very different approaches to guitar synthesis in a single box. Could this be the best guitar synth ever?

Moog Minimoog Voyager XL

Analogue Synthesizer

Thumbnail for article: Moog Minimoog Voyager XL

There’s no more revered name in the history of synthesis than Moog, and the Voyager XL aims to cement their reputation for top‑flight instruments. Is this the Rolls Royce of the synthesizer world?

Dewanatron Swarmatron

Analogue Synthesizer

Thumbnail for article: Dewanatron Swarmatron

This is a synth like no other, eschewing conventional controls, nomenclature and even an ordinary on/off switch. Is it destined to become a cult classic?


Software Synthesizer

Thumbnail for article: XILS Lab PolyKB II

The original was a diamond in the rough — so is PolyKB II a highly polished gem?

Spectrasonics Omnisphere 1.5

Software Synthesizer

Thumbnail for article: Spectrasonics Omnisphere 1.5

Spectrasonics bring yet more goodies to the Omnisphere party, aiming to make their highly acclaimed synth even better.

M-Audio Venom


Thumbnail for article: M-Audio Venom

M-Audio's debut synth may have a pristine white exterior, but it hides a sample-based synthesis engine capable of getting down and dirty...

Waldorf PPG Wave 3.V

Software Synthesizer

Thumbnail for article: Waldorf PPG Wave 3.V

PPG's Wave series were sadly beyond the budget of most of us, but, through the miracle of software, the powers of these innovative synths may now be within our grasp...

Novation Ultranova


Thumbnail for article: Novation Ultranova

The Ultranova may be a return to Novation's roots, but it's still a very forward-looking synthesizer...

Yamaha Motif XF7

Workstation Synthesizer

Thumbnail for article: Yamaha Motif XF7

Yamaha's long-lived Motif range continues to go from strength to strength. Could the latest model be the best Motif yet?

Mode Machines Xoxbox

Analogue Synthesizer

Thumbnail for article: Mode Machines Xoxbox

Everybody, as Fatboy Slim so wisely notes, needs a 303. However, with originals becoming ever more scarce and expensive, the dream of universal 303 ownership was starting to look unlikely — until now...

Vermona Mono Lancet

Analogue Synthesizer

Thumbnail for article: Vermona Mono Lancet

The peculiarly named Mono Lancet is an analogue synth of the old school, boasting two oscillators, a filter with a debilitating debt to Moog, and knobs galore!

Tom Oberheim SEM

Analogue Synthesizer

Thumbnail for article: Tom Oberheim SEM

Tom Oberheim has returned to the analogue synth fold with a revised and updated version of his classic 70s monosynth, the celebrated Synthesizer Expander Module.

Korg Monotron

Analogue Synthesizer

Thumbnail for article: Korg Monotron

Its their first analogue synth in 25 years, but is Korgs Monotron a toy or a tool?

Roland Gaia SH01

Analogue Modelling Synthesizer

Thumbnail for article: Roland Gaia SH01

If you don't like programming synths via obscure two‑line displays and arcane menu systems, the Roland Gaia SH01 could be just what you're looking for...

Moog Taurus 3

Bass Synthesizer

Thumbnail for article: Moog Taurus 3

The resurrection of Moogs stellar bass synth has caused a considerable stir. Can the Taurus 3 live up to the venerable reputation of its ancestor?

Doepfer Dark Energy


Thumbnail for article: Doepfer Dark Energy

The latest product of Doepfers modular know-how is the Dark Energy: a compact, powerful and hands-on desktop analogue synthesizer.

Cwejman Synthesis Modules

Modular Synth

Thumbnail for article: Cwejman Synthesis Modules

Wowa Cwejman is already in possession of a fine reputation for esoteric synth modules, but he hasn't run out of ideas yet. Join us as we take a tour of his latest creations...

SMS Planet 7 System

Modular Analogue Rack Synthesizer

Thumbnail for article: SMS Planet 7 System

Synthetic Music Systems have a unique approach to designing modular synths that are both high in quality and, wait for it, low in price. Let's investigate...

Analogue Systems Synthesis Modules

RS420 Octave Controller • RS100 MkII Low-pass Filter • RS370 Poly Harmonic Generator

Thumbnail for article: Analogue Systems Synthesis Modules

Analogue Systems' modules continue to develop and evolve. We take a look at a selection of the latest designs.

Cwejman Synthesis Modules: Part 3

DLFO Dual LFO • RM2S Stereo Ring Modulator • VCEQ3

Thumbnail for article: Cwejman Synthesis Modules: Part 3

We conclude our three-part exploration of Wowa Cwjeman's new range of exclusive analogue synth modules.

Cwejman Synthesis Modules: Part 2


Thumbnail for article: Cwejman Synthesis Modules: Part 2

Part 2: We continue our exploration of Wowa Cwjeman's new range of exclusive analogue synth modules.

Cwejman VM1

Analogue Voice Module

Thumbnail for article: Cwejman VM1

Swedish designer Wowa Cwejman has built a reputation for exclusive analogue synths. Now he's going modular, starting with the VM1 Voice module...

Buchla 200e: Part 2

Patchable Analogue & Digital Synthesizer

Thumbnail for article: Buchla 200e: Part 2

We conclude our look at synth pioneer Don Buchla's extraordinary new 200e modular synth.

Buchla 200e: Part 1

Patchable Analogue & Digital Synthesizer

Thumbnail for article: Buchla 200e: Part 1

Alongside Bob Moog, Don Buchla is one of the founding fathers of synthesis, and yet much less is known of him and his instruments. With this two-part review of Buchla's latest synth, and a history of some of his pioneering work, we hope to redress the balance...

Analogue Systems RS370 & RS375

Polyphonic Harmonic Generator & Expander

Having built their reputation on knob-heavy modular synths, British manufacturer Analogue Systems surprise everyone by bringing out a menu-driven additive synthesis module! But don't worry — the optional expander is covered with things to tweak and turn...

Cwejman Sound S1 MkII

Semi-modular Analogue Synth

Swedish company Cwejman have recognised that there is no way to build a cheap semi-modular analogue synth for mass-market sale these days (if there ever was). Enter the premium, but meticulously crafted S1 MkII...

Doepfer A100 Modular

Synthesis Modules

Since the launch of their A100 modular synth in the mid-'90s, Doepfer have been quietly adding modules to the system, some fairly simple, others splendidly esoteric. We explore some of the latest...

Lassence µVentury II

Patchable Analogue Modular Synth System

Belgian company Lassence are seeking to gain recognition as a small modular synth manufacturer with their new patchable µVentury II system. But there's plenty of competition in the homegrown analogue market these days. Does the µVentury II have what it takes?

Vermona Perfourmer

Four-voice Analogue Rack Synth

Formerly the East German state synth company (a great concept in itself), Vermona re-emerged last year with the MARS monophonic analogue synth. Clearly determined to win back their reputation, they've already returned with the four-voice Perfourmer...

WIN Great Prizes in SOS Competitions!


Home | Search | News | Current Issue | Tablet Mag | Articles | Forum | Blog | Subscribe | Shop | Readers Ads

Advertise | Information | Privacy Policy | Support | Login Help


Email: Contact SOS

Telephone: +44 (0)1954 789888

Fax: +44 (0)1954 789895

Registered Office: Media House, Trafalgar Way, Bar Hill, Cambridge, CB23 8SQ, United Kingdom.

Sound On Sound Ltd is registered in England and Wales.

Company number: 3015516 VAT number: GB 638 5307 26


We accept the following payment methods in our web Shop:

Pay by PayPal - fast and secure  VISA  MasterCard  Solo  Electron  Maestro (used to be Switch)  

All contents copyright © SOS Publications Group and/or its licensors, 1985-2016. All rights reserved.
The contents of this article are subject to worldwide copyright protection and reproduction in whole or part, whether mechanical or electronic, is expressly forbidden without the prior written consent of the Publishers. Great care has been taken to ensure accuracy in the preparation of this article but neither Sound On Sound Limited nor the publishers can be held responsible for its contents.
The views expressed are those of the contributors and not necessarily those of the publishers.

Web site designed & maintained by PB Associates | SOS | Relative Media