For some people, this year’s NAMM was amongst the more exciting of its kind. In addition to the now undeniable return of analog synthesizers, it will probably be remembered for the successful appearances made by smaller manufacturers. The German-based company Radikal Technologies is, amazingly, still an unknown for a not inconsiderable number of synthesizer enthusiasts. Jörg Schaaf and his “team” are having a go at changing this with the ACCELERATOR, shown at the NAMM and newly available.

Radikal Technologies ACCELERATOR

The ACCELERATOR is, in the basic version, an eight-part digital, virtual analog synthesizer. The five-octave instrument, which is solidly finished, can be extended with the optionally available voice expansion in two steps by 12 voices each time, to a maximum of 32 “real” voices. You may wonder about the use of the word “real” … well, if you are playing a 256-voiced instrument in the highest hierarchy of sound and your fading sounds are cut off abruptly, you will know why “real” is emphasized in the case of the ACCELERATOR.

A welcome side effect of this expansion is the organ emulation additionally available upon installation of the first expansion card. And doubly so, as the 61-fold polyphony of the organ emulation has no effect on the polyphony of the virtual analog sound generation. Above and beyond this, the first expansion stage brings an increase in the multitimbrality from two- to eightfold.

Radikal Technologies ACCELERATOR

The ACCELERATOR made available to us was a basic version (v1.52) and therefore featured eight parts with twofold multitimbrality. At this point I would note that the organ sounds of the audio demo “factory sounds 3″ come only from the subtractive sound synthesis.

Before we come to the tonal structure, a few words on the ACCELERATOR’s underlying sound production. As mentioned, the Accelerator is a virtual analog synthesizer. Radikal Technologies has decided to use floating point representation. Jörg Schaaf explanantion for this decision: “fixed-point numbers are perfectly suited for performing linear calculations. In acoustics, however, there are no linear processes. If you want to calculate, for example, a dynamic range as wide as possible with almost arbitrary precision, you quickly reach the limits of linear numbering systems. But if you have a number with many decimal places and exponents, you can calculate a markedly higher range of values with almost any degree of accuracy. The story of how Jörg Schaaf was unwittingly used as a tester for both calculation methods (fixed point versus floating point) by his programmer Andreas Tofahrn will follow another time. So much can be revealed at this point: it was related to the quality of the internal effects, which we will discuss later in this test report.

How is the sound put together for each voice of the ACCELERATOR?

The three oscillators have sweepable waveforms (Sine – Triangle – Saw – Square). Aficionados of the “supersaw” or other special waveforms will not find it here straightaway. However, a variety of different spectra can be created from the basic waveforms with the help of the time linearity modulation (TLM), phase modulation (PM) and the ring modulation (RM) between the oscillators 2 and 3 as well as the oscillator synchronization (sync to OSC2) available for OSC1. This adds some very intersting spectra, reminding on DX and PPG like sounds, to the classical waveforms. The TLM serves to compress and stretch the output waveform. You assume correctly: in the case of a square waveform, this leads to the well-known pulse width modulation. The TLM of the ACCELERATOR, however, can be applied to all the basic waveforms. Incidentally, phase modulation and oscillator synchronization can simultaneously act on the waveforms.

Another feature of the oscillator is the linear fine-tuning of the frequency, which is available in addition to coarse- and fine-tuning. As we are now discussing the oscillator section and in the ACCELERATOR these are mistakenly referred to as “VCO”. It is noted for completeness’ sake that obviously neither in the case of the so called VCO and nor of the VCFs and VCAs these are voltage-controlled elements of sound production. The names are misleading. The main criterion is of course another, the sound quality, and it raises the question of what is going on there. At this point so much: whilst other instruments involuntarily enrich the sound with artifacts even at lower levels, in the case of the ACCELERATOR you notice the cumulative computing power. Aliasing is, if at all, only noticeable in the very high frequency range and is not a real problem for the ACCELERATOR. The signal leaving the oscillators in the direction of the filter can be described as clean, but by no means hard or cold.

Radikal Technologies ACCELERATOR

The two multimode filters per voice can be used as low pass (12dB/24dB), band pass (12dB/24dB), high pass (12dB/24dB) and notch (12dB/24dB) filters. The filters can be connected in series or in parallel and the usual suspects are available as parameters: cutoff, resonance, EG depth and key scale. A positive feature is that the cutoff frequency offers an edit range from -255 to +255. Filter FM or filter distortion are not currently offered. But there is another, special filter. For this you move the cursor on the easily-readable display to the next tab, “STR”. Those who associated “strings” with this are already getting close to what is on offer. Thw filter is named as a “String Filter” because it sounds like a plucked string when noise is used as sound source. Actually it is digital delay with damped feedback loops with the ability to attenuate the treble and bass range of the feedback. You have probably already heard the guitar and flute sounds on the manufacturer’s website or on YouTube. These “noisy” sounds are due in part to the use of the string filter.

What is probably a pressing question at this point, whether the ACCELERATOR also features noise, can be answered with a clear and simple “yes!”. The noise source has its own multimode filter section independent from the other filters. Not bad, especially since it can be modulated separately and thus contribute to further enriching the sonic possibilities. Therefore the ACCELERATOR really has three multimode filters and one string filter per voice. For the connection of the different filters please have a look at the Voice Architecture above.

Now the question arises of just how they sound. At this point let us refer to the audio files. So as not to avoid a short resumee – the filters all sound excellent. If I had to make one criticism at this point then it would most likely be that the filters sound a little hard at high resonance. To avoid any possible misunderstanding, we are talking about great-sounding filters, which make some of their competitors look pretty old!

Radikal Technologies ACCELERATOR - back

According to the classic structure, the filter section is followed by the VCA section. This is designed in stereo i.e. the two filter outputs can be independently distributed in the panorama. As could be expected, it can create beautiful broad sounds, of which there are several in the work programs. It would not be the ACCELERATOR if there were not a plus in the VCA section. This is a fully parametric, three-time EQ that can give the sound that final polish.
What would all this be without modulation? Radikal Technologies had the same thought and sent the ACCELERATOR on its way with six envelopes and four LFOs. Two of the six envelopes are hardwired to VCA1 and VCA2, but above and beyond this they can of course also modulate other targets. The AHDSR (H = hold) envelopes are not loopable and cannot be dealt with nearly as fast as they are. At this point let us refer once more to the audio demos, as some of the drum and percussion sounds equally underpin the speed, such as the sound “Peter Baumann”. For those who want to convince themselves on the instrument itself these programs are recommended as examples: A9.7 “conga slap”, A9.8 “ElectronicFrmDrm” or several of the bass sounds. The envelopes are among the fastest of their kind and play their part in a very good and powerful sound.

Radikal Technologies ACCELERATOR - solidly finished and good design

Now for the LFOs. There are three of these per voice, with the fourth LFO serving to modulate the entire PART. The low frequency oscillators are well-behaved and do honour to their name. Here, I would have preferred to see a much higher frequency range (listen to their max speed in the audiodemo) and I hope for a future update to that effect. The LFO waveform can be stagelessly adjusted from sinewave to triangle, sawtooth, square and in the case of the LFO also to random. Modulation depth can be controlled by using the keyboard’s channel aftertouch or via modulation wheel or pedal.

ACCELERATOR monochromic graphic display with RGB backlight

And so we have already reached the modulation matrix. This would not have been readable if we had provided it as a photo in our maximum display size and is therefore available as a pdf File. To operate the ACCELERATOR, and this brings us to the controls, you have to click through the “MOD” list using the “up/down” arrow keys found on the left of the display. The large number and variety takes its toll, so if you want to edit the MOD source and target at the bottom of the list you will find no way round operating the “down” cursor 31 times. Admittedly, this eventuality will not arise often, but it is cumbersome. Radikal Technologies is aware of this and is working on a solution in the form of an editor. Jörg Schaaf was nice enough to provide us with a Screenshot of the editor in advance, which you see in the figure below.

preview ACCELERATOR Editor - VCO ©RT

As well as the modulations discussed above, effects have become an indispensable component of modern synthesizer sounds. This factor is accommodated by the ACCELERATOR by internal effects. The four FX buses are available even in the basic version and are utilized to the extent that no truncation of the reverb and delays arises. This feature, designated as “Voice Remain”, also makes it possible to select a new sound while holding a chord, without cutting the old off. An advantage not to be underestimated, especially live. Also beneficial is a limiter found in the bus, which should not go unmentioned.

By pressing the FX/Dry slider once, you reach the effect menu. The choices on offer are distortion, delay, phaser, leslie, chorus, reverb and EQ. They are all from good to very good quality. That the reverb does not sound as pro as a dedicated specialist a la Briscati, Lexicon or TC goes without saying. For good reasons as some of them cost more than a fully expanded ACCELERATOR. As it is in continuous use in the audiofiles, I will leave you to judge for yourself. Chorus and phaser are excellent, and distortion and delay are their equals.

If you also are among those who also want to find out quickly how the sound DRY sounds, then one press on the FX-BYPASS switch underneath the volume control will suffice. If you want instead to reduce the effect proportion quickly, turn the FX DRY/WET control to the right of the display. In the audio file “Factory Sounds 3″ I have made ​​plenty of use of it. From about 4:19 you will hear the phrase rehearsed first with a high and then with a low effect level. At the beginning of the same audio file you can hear the very good rotary effect, followed by a short oscillator sync sequence. In the sounds following this, reverb, distortion, delay and chorus are used. In short, the effects section is very pleasing.

ACCELERATOR - Direct Edit Section

Let’s look again at the controls of the ACCELERATOR. On the top left of the case is the DIRECT EDIT SECTION where you can undertake the sound programming as well as the programming of the included step sequencer. Plural? Indeed. Up to eight step sequencers with 32 (!) polyphonic steps can be programmed. So that this is not all, three additional sequencer lines for parameters automation are available. Arpeggiator? Well… there is not only just one, there are up to eight polyphonic arpeggiators. Nothing stands in the way of one-fingered compositions.

ACCELERATOR - Advanced Edit Section

To the right of the edit section, and therefore almost in the middle of the instrument is the ADVANCED EDIT SECTION. At its center is the monochrome graphic display, left of the cursor and below and surrounded by three encoders. What has remained unmentioned until now: if you hold any of the switches or controllers for about a second a “help” function appears that describes the particular function. Nice!

ACCELERATOR - Sound Organisation + Selection

On the right side of the casing surface is the SOUND ORGANISATION. I initially had some problems with this, which were rapidly solved on consultation of the manual. The sounds can be played Single, Split, Dual or Multi Mode and are stored in ten sound categories. What I miss at this point is a unison mode, which I herewith place on my wishlist. However, this would inevitably lead to a fairly restrained level of the ACCELERATOR, as the already high level would in this case probably blow one or the other of the speakers.

In the ADVANCED EDIT SECTION you will find the RANDOM function, which is worth to be described a bit more in detail. This function helps to get to new sounds quickly. In its implementation it rather corresponds to a “recombination”, because the sounds stored in the memory always serve as the starting point. From these sound elements the appropriate categories are used and recombined. Something which at first does not sound very spectacular but leads to a higher number of directly usable musical sounds in practice. In simplified terms, it works like this: the settings of the oscillators are taken from PAD A and combined with the filter settings of PAD B; from PAD C the modulation settings are taken and from PAD D the envelopes, and finally from PAD E the effect settings. Smart. To make this somewhat clearer, we have included a short Video. Of course, with all of this on offer you become greedy and wish for a “true” randomize function on top. Although the principle of recombination can also be manipulated by assigning the individual sounds to the wrong categories. The drawback of the matter is, of course, if you are playing live and want to quickly call on one from the PAD category, but have stored this elsewhere… Anyway, the RANDOM function could prove especially valuable in the studio and will probably not only wow me.

ACCELERATOR In- and Outputs: MIDI In, Out, Thru, Expression Pedal an Footswitch Inputs, galvanic isolated USB connector (USB MIDI class device), SPDIF digital output, four analog outputs (converters: PCM1754 from TI, 24 Bit, 192 KHz, although used @ 96 KHz + CS4265-CNZ from Cirrus Logic), two external balanced inputs (from microphone to line level), headphone output with a discrete headphone amp

The ACCELERATOR can also be used as a master keyboard and offers several features that will especially be appreciated in a live environment. In addition to the voice remain feature I would count the CHAIN ​​function as one of these. Each program can therefore save the play mode (single, dual, etc.) and quite easily call up the sounds in sequence. The 3D tilt sensor, which is dispensable for me, will probably be highly estimated by musicians playing live. Jiggling about with the ACCELERATOR in the studio will probably never be my passion, but you never know. A ribbon controller would have certainly raised more euphoria in me. Anyway … at just 9kg and with the above-mentioned features and very good finish, the ACCELERATOR could find quite a few friends amongst live musicians.

Now we come to use in the studio and with it to my second main criticism. The first demo recordings were quite difficult, if not to say tedious! For some reason the ACCELERATOR looped the MIDI data, looking for a “Local Off” did not help me either as there is none. This means that for recordings I always had to disconnect the MIDI to avoid MIDI data chaos. Using the USB connection helped once or twice, but it was not always the most reliable alternative. Fortunately the restart only takes approximately 5 seconds and I was therefore inclined to be moderate, especially since such problems only arose in connection with the DAW. However, that was the point where I made contact with Jörg Schaaf. Fortunately, within a very short time came not only a friendly but above all, a helpful answer. To keep this short, at the end was v1.54, which was quickly transferred to the ACCELERATOR via USB. With this version the MIDI problem seems to be solved. You often read or hear about the “service wasteland of Germany” (in Germany of course), which may be true for one or the other representatives of large manufacturers but in the case of Radikal Technologies this is definitely not justifiable. The service provided can only be described as exemplary. The core team is made up of only two people, Jörg Schaaf and Andreas Tofahrn and is characterized by competence and customer service. Here two people have come together who complement each other excellently … to which the ACCELERATOR bears witness to and with this you made it already to the

Radikal Technologies ACCELERATOR

Summary

With the ACCELERATOR, Radikal Technologies has brought a tool to market that is characterized by attention to detail. Obviously they have not only been thinking about possible features but have also put them into practice accordingly. The decision to go for quality rather than quantity is perceptible and can only be welcomed. The top priority should ultimately always be the sound quality of an instrument and here everything is in the ACCELERATOR’s favor. Warm, soft pads, dry or with a high effect level, broad sounds, you can find them all within the 500 single sounds. Anyone who is not happy with that can take up tools themselves or use the ACCELERATOR’s RANDOM function to coax out new creations. Bass sounds have the necessary power and energy as well as precision in the lower frequency range, cutting solo sounds as well as distorted one or 70′s style lead sounds is something it manages easily. Percussive sounds? No problem, good synthetic drum sounds are on offer as standard. Even the pitch bending is “different” compared to some other instruments. This struck me even after the first few minutes, that you can get down to regions that are dangerously low for loudspeakers and recording equipment.

I can already hear the questions, “and … does it sound like a Jupiter-8? “No. “Does it sound like a Prophet 5?” No. “Does it sound like an Oberheim …. ? ” No. Counter-question – does a Jupiter sound like a Prophet? There you go. The answer is, it sounds like the ACCELERATOR. What should not be taken to mean that it wouldn’t equal the corresponding sounds of the classics mentioned. I would tend to think that most of the factory sounds are drawn from this time. Which doesn’t go to say that it doesn’t easily manage sounds that would be suited to modern dance tracks. Only the factory sounds found on the test instrument are more in the classic direction. The “Factory Sound 2″ audio file tries to show that it can also sound “digital”. The opportunities the oscillators offer to generate different spectra and the variety of filters is, given the sound quality on offer, an optimal prerequisite for being happy with the ACCELERATOR for a long time. The few criticisms can be quickly enumerated again. There is the frequency of the LFOs, which is too low in my opinion, the missing unison mode as well as a local off function. The not insignificant MIDI problem seems to be a thing of the past since the version 1.54.

Let me come back to the somewhat provocative question raised in the title of this review. In fact, due to the new, faster processors, and above all to the improved algorithms, a new generation of virtual analogue synthesizers has appeared, it is not a quantum leap but an example of a new VA generation. The discussion of whether the allegedly insufficient number of voices in times where you can quickly record 64 tracks on an iPhone is hardly understandable, and with the installation of an expansion of voices you have 20 synthesizer voices as well as a 61-voice drawbar organ on top of that.

If you have the opportunity to play the ACCELERATOR in a music store, then take a pair of headphones, and above all the time. Be careful with the volume, by the way, because what comes out of the Accelerator comes with a decent level! I did not want to put another synthesizer in my studio, on the contrary, actually the plan was to reduce my equipment. But now I must find a worthy place for it, after checking my bank balance, because it seems that it will not be making the return journey.

list price ACCELERATOR: € 1,990.-              
voice expansion, available only from Radikal Technologies: € 299.-
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Addendum Feb. 14th 2012:
ACCELERATOR Editor News. Radikal Technologies develops a new Editor from scratch. It will be completely independent from Lemur Software.

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In all ACCELERATOR audiofiles only the internal EFX were used. Organ Sounds in “Factory Sounds 3″ are virtual analog sounds and NOT sounds of the Drawbar Organ Emulation. The “Drums” demo was recorded by using an AKAI MPC3000. All drum sounds were directly sampled into at, without any compression, EQing or additional EFX then those already part in the ACCELERATOR. The reason to use the MPC was the two part multitimbralitiy of the basic version. You can find all audiofiles also in our Listening Room with a list of the used Factory sounds.