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Hollow Sun Classic Keyboards

Akai-format Sample CD-ROMs By Nick Magnus
Published October 2005

Hollow Sun's vintage keyboard sounds go against all the current sample-library trends, being supplied on CD-ROM rather than on dedicated hard drives, and weighing in at Megabytes in size, not Gigabytes. But how do they sound...?

Hollow Sun Classic KeyboardsIn an age when sample-library producers are increasingly concentrating their efforts on enormous software-based libraries, it is rather reassuring to come across these new libraries from Hollow Sun which demonstrate that there is still plenty of mileage to be had from hardware samplers. With care and attention to detail (and of course sufficient RAM), these 'old beasts' can still give software samplers a run for their money.

This collection comprises five separately sold CD-ROMs, each dedicated to a specific 'classic' instrument. At the time of writing, they are only available in Akai S5000 and S6000 format, which is also readable in Akai Z4 and Z8 hardware samplers, and also in MPC4000 sampling workstations (but not in the older S1000, S3000 or their derivatives). However, as I write this, plans are apparently afoot to make the sounds available in Native Instruments' Kontakt 2 format, Emagic/Apple EXS24 format, and possibly others.

For the majority of this review, I used an Akai Z8; this way, I could be sure that the sounds I was hearing were the way Hollow Sun intended them to be. However, Kontakt 2, my software sampler of choice, claims to be capable of importing raw Akai S5000/6000-format samples, so while I was at it, I couldn't resist trying out the libraries on my software sampler, just to see how accurately the sounds were translated (see the box at the end).

Library Contents


'Natural', 'Chorused', and 'Swept' samples.


Contains the following Mellotron sounds: 'Boys Choir', 'Brass', '8-voice Choir', 'Flutes', 'Mixed Strings', '3-Violins', and 'Watcher' (a string/brass mix).


Contains 26 root sounds, many of which have specially programmed variations.


Consists of 11 folder categories: 'Bass' (22 Programs), 'Bells' (nine programs), 'Clavinets' (seven Programs), 'SFX' (three Programs), 'Strings' (five Programs), 'E-piano' (11 Programs), Guitar (eight Programs), 'Leadlines' (16 Programs), 'Organs' (15 Programs), 'Pads' (33 Programs) and 'Percussive' (14 Programs).


Consists of two folder categories: 'Combis' (31 Programs) and 'Programs' (33, well, Programs).

Definitive CP70

The CP70 must be an elusive sound to capture; the sampled renditions of this instrument that I've encountered so far seem to lack a certain je ne sais quoi, somehow failing to convey its unique character convincingly. It's notable then that Hollow Sun have rendered this amazingly accurate and instantly recognisable representation, which is a real pleasure to play. Every note has been sampled at its natural length with no looping, using two velocity layers. Employing some judicious velocity crossfading and subtle velocity-sensitive filtering of the 'hard' samples, the dynamic response is surprisingly wide, smooth and realistic. Key velocity also modulates the 'soft' sample start points, so that the hammer thump is gently attenuated at the softest playing levels. As on a real CP70, the high notes (above A6) ring on undamped when a key is released. For all notes below A6, a key-off damper release noise rounds off the illusion rather nicely.

Three representations of the CP70 are offered here: so-called 'natural' samples, sounds sampled with chorus, and 'swept' samples. The last of these does not incorporate some gratuitous filter sweep, but is the sound of the strings being 'thrummed' using a fingernail or plectrum with the sustain pedal held down — very Hammer House Of Horror. The CP70 disc is by far the most RAM-hungry instrument of Hollow Sun's libraries, needing 180MB for the full natural instrument and 188MB for the chorused version. For samplers with rather less RAM than that, 'Lite' (with two velocity layers but fewer multisamples) and 'Ultralite' natural and chorused versions (with just one velocity layer) are provided, requiring just 69MB and 39MB of RAM respectively.

Newtron Bomb

The Mellotron surely needs no introduction. Seven of its iconic original sounds are presented here: 'Boys Choir', 'Brass', '8-voice Choir', 'Flutes', 'Mixed Strings', '3-Violins', and 'Watcher' (the mixture of '3-Violins' and 'Brass' used on Genesis's 'Watcher Of The Skies'). Each sound is presented in 'A' and 'V' versions. 'A' is for 'authentic', in other words, with an organ-like amplitude envelope, and with no velocity-to-amplitude routing, just as on a real Mellotron. Perhaps these could have been given an extra touch of authenticity by the addition of a velocity-sensitive attack time; as it is, the 'spit' at the notes' start is always present, whereas notes on a real 'tron can be 'coaxed' into life by playing gently. Still, you can always program that detail in yourself if you feel strongly about it! The 'V' versions also have the organ-like envelope, but with velocity mapped to amplitude response. With the exception of the Brass, alternative 'A' and 'V' versions are provided for each sound with slowed attack and release times for instant big and washy soundscapes, and you can, of course, tailor the envelopes to your own taste. The starkly gothic 'Mixed Strings' (a blend of '3-Violins' and 'Cello') include a bonus Program, 'Phaedra Strings' that utilise the Z8 synth engine's built-in Phaser effect to recreate the classic dreamy Tangerine Dream 'tron sound from their album of that name.

All 35 notes of each sound have been sampled, the keygroups being authentically restrained to the Mellotron's original 35-note range. Slightly less authentically, but in my book very usefully, all notes have been looped, enabling you to sustain them infinitely — unlike on the original Mellotron, where the tape loops ran out after eight seconds! The loops are beautifully executed and utterly seamless, thanks to Hollow Sun's use of Antares' Infinity looping software. The purists out there may spontaneously combust with rage at this revelation (indeed, Mellotron samples per se are usually sufficient to cause this disturbing phenomenon) but let's be reasonable — you're not obliged to play notes for more than eight seconds, and can simply stop playing them after that time has elapsed. Or failing that, you can set the amplifier envelopes to close down after eight seconds...

I found the overall character of these samples to be superb. The '3-Violins' are perhaps a tad bright for my taste, but applying a soupçon of two-pole low-pass filtering soon had them sounding just right. In comparison to my extensive personal collection of Mellotron sounds garnered from numerous sources, this set beat mine hands down for sheer presence and clarity within a mix. Whilst some of the Mellotron sample material generally available has often been processed in some way, and hence removed from what you'd hear if you simply plug a 'tron straight into a mixing desk, these 'raw' samples, taken directly from the output socket of the real thing, demonstrate how magnificent this instrument can sound.

Definitive PPG: Selected Highlights

  • '5ths': Chunky and analogue-ish, with a pleasing digital 'twang'.
  • 'Aaaah Bell': It could only be a PPG!
  • 'Big': Huge bass end, also great for majestic prog-rock chords.
  • 'Chime': This was all over pop records of the '80s.
  • 'Mello Swell': The PPG wears its analogue hat, and gets warm and cuddly.
  • 'WT Brittle': Gritty wavetable antics.
  • 'PPG Vox': Like a Roland VP330 vocoder, but without the ensemble effect.
  • 'WT Soft Sweep': An intriguing chime with a modulated wavetable.

Definitive PPG

Just as the Mellotron provided what became iconic sounds of the 1960s and '70s, the PPG Wave 2.2 did the same for the '80s. Expensive and sometimes unreliable, ownership was very much a status symbol in the early part of that decade. Perhaps now isn't a good time to mention that I couldn't afford one...Hollow Sun Classic Keyboards

The PPG's wavetable synthesis made possible a new generation of off-the wall sounds that, being unique, were not always easy to define or categorise. However, its hybrid digital/analogue design made it equally adept at masquerading as an analogue synth, as some of the Programs in this set demonstrate. Each folder on the disk contains a basic sound Program, often accompanied by supplementary Programs specially created to use additional synth processing in the host sampler. Sustained samples are long and looped (seamlessly as always) and multisamples are generally taken at every minor third. To ensure a consistent timbre for the entire key range, Hollow Sun have applied positional crossfading between keygroups, and it works extremely well. The transition from one sample to the next is virtually indistinguishable, with no unpleasant phasing problems or overly apparent transposition of time-based movements in the sounds. Essentially, these are classic PPG sounds, which you can further filter and modulate as you wish.

FS1R Collection

Released at the end of 1998, the FS1R module was the last of Yamaha's dedicated hardware FM synths, and probably the best specified of them all. Powerful features such as formant shaping, formant sequences, eight operators, three effects processors and four-part multitimbrality took it far beyond the original DX7's concept of FM, yet despite all this it curiously failed to capture the public imagination, and rather unjustly faded into relative obscurity. Backwards compatibility with the DX7 enabled it to produce all the classic, clanky FM tones, but it was especially adept at creating complex, layered evolving sounds, with its formant-shaping capabilities placing the emphasis on vocal textures.

This collection is a broad illustration of the FS1R both in classic FM guise as well as its more unfamiliar, otherworldly personas; clanky basses, delicate electric pianos and shimmering bells rub shoulders with evolving pads, haunting sound effects and warm, analogue-style textures. All 'decaying' sounds are sampled to their full length, and all sustaining sounds have been looped to Hollow Sun's usual high standards. Positional crossfades provide a smooth timbral progression across the keyrange. Although a few of the 'classic'-style FM Programs will already be familiar and accessible to most people by other means (using a DX7 or NI's FM7 software), the real inspirational content of this set is to be found amongst the various pads, organs and sound-effects-type textures, although I'd perhaps like to have seen more demonstrative examples of the formant textures unique to the FS1R.

FS1R Collection: Selected Highlights

  • 'Glass Echo': Great for bubbling arpeggios in the upper range.
  • 'Nightmare': A brittle, scary, evolving texture — don't open that cellar door!
  • 'Big n Bright': Powerful mono lead which doubles as an Oberheim OB8-style polysynth.
  • 'Full Organ': Reminiscent of Tony Banks' Lamb Lies Down-era Hammond.
  • 'Nebulous': A glassy, dreamy pad with bells.
  • 'Starship': Phasey, vocal, undulating pad.
  • 'The Seeker': Delightful, rather querulous-sounding metallic vocal pad.
  • 'VocoTouch': Rich, swirling pad with modulating formants.
  • 'VoxPhase': This animated pad almost seems to be holding a conversation with itself!

M/01 Collection

The Korg M1 is surely the grandaddy of all sample-and-synthesis keyboard workstations, and spawned a long line of subsequent variants that now spans a respectable three decades. This collection features a broad selection of typical sounds from the M1 and 01 workstations (and their rackmountable spinoffs), and is divided into two folders, Programs and Combis. The former contains examples of classic two-oscillator M/01 Programs, while the latter contains examples of the more complex M/01 sounds that could be created by layering Programs together, with effects, in Combi mode. The samples include a varied and nostalgic selection of bells, electric pianos, string and vocal pads, atmospheres, basses, and hybrids of these. Curiously missing is that famous M1 patch, 'Universe' — nevertheless, this useful and versatile soundset does not suffer from its absence!

M/01 Collection: Selected Highlights


  • 'Airways': A whimsical, percussive vocal pad.
  • 'AnalogPad': Warm and stately.
  • 'DWGS EP': A Korg DW8000-type electric piano with velocity-sensitive tines.
  • 'Fantasia': Not quite a Roland D50, but very evocative of the '80s.
  • 'HarpsiFunk': Wear your periwig backwards and get down...
  • 'Space Wing': Delightfully atmospheric, highly detailed.


  • 'Nebulae': A Korg classic.
  • 'AnaStrings': Splendidly regal, in a baroque sort of way.
  • 'Bell Come': Rich, echoing bells with a brass pad.
  • 'First Snow': Edmund and Lucy couldn't believe it — they had found Narnia!
  • 'Sing2Me': One of Korg's lovely vocal pads.
  • 'Masterfisa': Just play 'Captain Pugwash' on this!


Notably, no compressors, high-quality channel strips, noise reduction, pre-sample 'sweetening' or other 'corrective' measures were involved in the sampling process for these libraries, so you are free to treat the sounds just as if they were coming straight from the source instruments. And yet, the quality of these instruments shines through. The CP70 and Mellotron discs are arguably the flagships of the set, the CP70 largely due to the relative scarcity of comparably realistic sampled alternatives. Newtron Bomb, too, is a winner, notwithstanding the current glut of similar offerings available. It sounds as good as Mellotron samples are ever likely to, and has potential for almost unlimited customisation. What's more, the musical functions of the CP70 and Mellotron are clearly defined and well understood — you know exactly what to expect, and these libraries deliver just that. On the other hand, the PPG, FS1R and M1 are each capable of a producing a vast palette of sounds, so nailing down 'definitive' representations of these is rather more subjective, and hence not quite so clear cut. Nevertheless, the collections here ably show off the range of these three instruments and should provide something for everyone, from bread-and-butter classics to some of the more exotic aspects of wavetable synthesis, FM or S&S stylings. If your curiosity is piqued and you need a little help deciding which to buy, try listening to the audio demos on Hollow Sun's web site — they may well decide for you.

The Libraries Under NI Kontakt 2

Loading the Akai Programs directly into Kontakt 2 produces a mixed bag of results. The structurally simpler Programs (those from the PPG, FS1R, and M1 discs) fare well — positional crossfades are imported correctly, and amplifier envelopes are mostly in the right ballpark. Filter settings, however, consistently needed adjustment. Velocity-to-sample-start-point sensitivity (used on the CP70 disc) also needed tweaking (the appropriate Kontakt Groups must be in 'sampler' mode for this to work at all), and velocity crossfading (also used on the CP70 samples) was not imported correctly. A number of Programs refused to load at all, causing Kontakt to crash. However, the libraries aren't designed for use in Kontakt 2, and this test was done purely to see if I could get them working on my software sampler. Apparently, by the time you read this, Hollow Sun will be offering 'native' Kontakt 2 versions of each library, which should resolve the problems I experienced.


  • Classic sounds reproduced to a very high quality.
  • Seamless looping.


  • Restricted to Akai S5000/6000-format at the time of writing (although others are supposedly on the way).
  • I'm trying hard to think of any more...


A high-quality, well-rounded collection of classic instruments, all of which deserve to become a valued part of any samplist's armoury. There are plenty of inspiring synth sounds, the Mellotron sounds are as fine as you'll hear anywhere, and the CP70 is especially outstanding.


Hollow Sun libraries, US $55 each, plus an $8 flat-rate postage and packing charge (a total of approximately £35 at time of going to press).