Friday, June 11, 2021

VST SYNTH REVIEW: Cherry Audio Eight Voice. SEM VST Emulation.


Cherry Audio's instrument VST releases are coming thick and fast at the moment, having only got pen to paper on this review that the new PS-10 was announced (a polyphonic Korg MS-10 emulation with upgraded patch section and on-board effects). 

Now, before starting, I have to admit straight up that I've never played a real life, hardware Oberheim 8-Voice, 4-Voice, or 2 voice, or indeed a real life hardware Oberheim SEM. The nearest I've come is extensive use of the Hy-Plugins Mono SEM synthesizer VST which I happen to love. So authenticity is a difficult one to gauge here. 

Incidentally, Hy-Plugins Mono SEM is freeware and can be downloaded here:

The original Oberheim SEM was developed as a keyboard-less synth that could be controlled via a sequencer (probably Oberheim's own DS2) or via a keyboard. By mounting multiple SEM units into an enclosure with keyboard, it was possible to assemble polyphonic synthesizers and so the 2, 4 and 8 Voice synthesizers were born.

Whilst the synths were capable of awesome sounds (the 8-Voice had a total of 16 oscillators) they did have one major drawback, which is happily overcome with this software emulation. The controls are not 'multiplexed' across all voices which meant that to adjust the filter cutoff, for example, you had to adjust the filter of all 8 modules (for an 8-Voice). 

Whilst this actually opened up some creative possibilities, with every voice of a 'sound' having completely different settings and sound, the cons really outweighed the pros. 

Thankfully, controlling eight SEM modules in 2021's software realm is far easier than with 1977's electronic hardware technology, so controlling the 8 SEM modules of Cherry Audio's Eight Voice flexible and easy using two voice groups to determine which SEM modules are 'linked'. You can create stacks or splits or combinations of the two with this flexible voice architecture and control. A modern patch storing and recall system further enhances this concept which was unavailable to the hardware designers in 1977. 

Voice Assign, Key Range, and Link Group Controls. 

The bottom section of each SEM module and the Link Group buttons in the master section are the new software additions that make the Eight-Voice much more usable than it's seventies hardware counterpart. 

These sections allow much more flexible control than seventies hardware electronics allowed. These three sections allow the individual SEM modules to be linked (and unlinked) instantly so you don't need to adjust the parameters of every unit used in a 'patch'. They also determine whether the module is triggered by the keyboard or the mini step sequencer, select from three mono and two poly modes, and obviously, the key range determines the playable note range for each SEM module. 

So I guess at this point, I'm thinking, and maybe you are too.....why not just build an 8 voice polyphonic SEM with 'multiplexed' parameter control. Or maybe something with two 8 voice SEMs, one with the mini sequencer or for another stack/split sound. It would certainly be a smaller, more manageable GUI. Well I guess the answer is that the software Eight Voice gives you the best of both worlds. You can set up the basic sounds using linked modules and then unlink them and dial in some subtle (or not so subtle) differences to each module. I guess authenticity is also a factor here. Maybe a single 8 voice SEM would just be seen as a bit of shortcut and of no historical significance since it never existed. 

Oberheim SEMs.

So since the Eight-Voice is essentially eight synthesizer modules contained within a flexible system of control, it makes sense to focus on a single SEM module and imagine it repeated 8 times. 

Each SEM module is a two oscillator, filter, dual envelope and LFO synthesizer. 

The syncable oscillators offer saw and pulse waves with 4', 8', 16', and 32' pitches and frequency detune with pulse width setting and modulation. 

The filter section is a 12db/oct state variable resonant filter with fully variable type control from low-pass to high pass via notch filtering. Band pass filtering can also be employed via a dedicated switch. The filter section also acts as a mixer, adjusting the levels of the two oscillators saw and pulse waveforms. It might be worth mentioning at this point that the Oberheim filter here is a bit of a departure from most American hardware synths of the seventies which usually employed 24db/oct ladder filters a la Moog. Maybe one of the factors that gave the SEM and it's keyboarded offspring their unique sound.

Each SEM has 2 envelope generators fixed to modifying amplifier and filter respectively. They are slightly different as they are three stage with the decay section doubling as both decay and release. 

Each SEM has an LFO (1) with a fixed sine wave. This can be assigned to each VCO or the VCF frequency cutoff. Because these are available on each SEM they can have different rates. A global LFO (2) with a number of waveforms is also available. This can also be assigned to the VCO frequency of each oscillator, or the VCF cutoff, but as it's a global LFO, only a single rate is available. 

Below the LFO and envelope generators is the voice assign and keyrange section which we dealt with earlier, plus an output section with pan, solo and output level settings. The solo function is really useful when programming so you can silence other modules and monitor each SEM individually with a single button push.    

Eight Voice Master Section.

Master Section (Left)

Eight Voice's Master section starts with master tuning followed by a filter offset control. This closes or opens the filters of all the SEM modules by the same amount. Quite handy for instantly brightening or darkening things. 

The two link groups follow with the poly assign mode switches underneath. These determine how notes are assigned and 'stolen' if you go beyond the 8 note polyphony. 
Portamento is dealt with in the next section with various polyphonic and mono portamento modes. You can assign portamento to one poly group but not another so some notes glide and others don't. With maximum 8 voice polyphony, polyphonic glide effects can be a little limited.

The aforementioned LFO2 controls come next followed by the 8 voice Mini Step Sequencer. Compared to most modern sequencer and arpeggiator applications this will seem a little basic, but it is in keeping with the vintage and era, and it is an integral part of the plug-in with the ability to assign the sequencer to single or groups of SEMs. Check out the default preset 'Reflective Mood' with a sequence triggered from the bottom section of the keyboard from SEM 8 and the rest of synth providing a seven voice pad above. The Mini Step Sequencer can be synced to the master tempo which in turn can be synced to the tempo of your DAW software.

Master Section (Right)


Finally, some modern digital effects are provided with a reverb and delay section. The delay section has enough control that it can also create chorus and flanging effects.

The Top Toolbar.

Top Toolbar (Left)

The top section of Eight-Voice deals with patch loading and settings including a 'New' patch function which sets the synth up with the all oscillators and filters fully open producing a saw/pulse polyphonic comp style patch. 

Undo/redo buttons are provided. Really handy.

The settings menu deals with global parameters including setting up the audio if you're in standalone mode. 

Midi lights and an 'all notes off' panic button is provided in case of any stuck notes if you change channels  while a note is sounding. I wish all VST synths had this!

Top Toolbar (Right)

One of my criticisms of Eight Voice was going to be that the large GUI is a little difficult to navigate and even with the zoom function you still can't see the lower controls in close up. However, this is fixed with the 'Focus' control allowing you to focus the GUI on pairs of SEM modules, the master control strip (left section), the Mini Step Sequencer, or the FX section. So problem solved. 

How Does The Cherry Audio Eight Voice Sound?

OK. So that's the 'nuts and bolts' of the Eight Voice, but what does it sound like?
Well as I mentioned earlier, I really like the sound of the SEM, although I've really only got the Hy-Plugins Mono SEM to go on. 

It offers a different kind of sound to many other synthesizers of the era which yo would expect. The oscillators and filters are very different to something like the Minimoog with fully variable pulse width and 12db state variable filters, which perhaps make it sound a bit brighter, not quite as warm as some other synths of the era. 

I guess at this stage it's worth pointing out that Eight Voice is available as a free 30 day demo version, so probably the best thing is to try it for yourself, and it comes with a healthy selection of factory presets. Some of my favourites include 'Diane Sawyer' a bass filter sweep a la Rush, 'Noisy Res' is a wonderfully squelchy bass patch and 'Good Ol Funk' is a fat 70s bass patch. 

The Mini Step Sequencer plays it's part in the factory patches with 'Who's There' offering Baba O Reilly in an instant, 'Dance Floor' gives is a thunderous take on the '4-on-the-floor' dance motif, and 'Solar Phases' offers some spacey ambience. 

As you would expect, a 16 stackable oscillator monster like this should be able to serve up some impressive leads sounds and 'Synching Lead', 'Sawblade' and 'Lyle Legend' don't disappoint.

For pads 'Angels Songs', 'Fluttering Fairies' and and 'Stellar Orbit' showcase Eight-Voice's abilities and 'Rock Poly' and 'Jump Higher!' are nice fat poly comps.


I guess all designers of 'vintage' synthesizer emulations have to walk the line between authentic and usable. When considering software enhancements to the hardware equivalents they have to weigh up what might enhance the capabilities of a synth (and, honestly, this path probably goes on forever) whilst keeping the authenticity that made the synth a classic in the first place. 

In the end, Eight Voice is a great sounding VST emulation with software enhancements that make the classic more usable and enjoyable whilst remaining authentic to the instrument's quirks and eccentricities that almost all vintage analog synthesizer all had, at least all the classic ones.
I guess the one thing I might have liked to have seen is if more polyphony could have somehow been built in. Obviously, polyphony is only usually only limited to a computer's CPU capability and RAM, so I don't think it would have been a problem from that point of view. Maybe a polyphony parameter for each SEM. But I guess that might have made the voice assignment ad poly modes more complex.
Anyway.....other than that, I really liked Eight-Voice. It's not difficult to find your way around it and program once you get the basics of the software enhanced SEM grouping and control. I would recommend tweaking some of the factory presets first and then moving on to some programming from scratch via the 'New Patch' selector. Oberheim's SEM is a synth module that rewards a bit of time and effort in spades.

Cherry Audio provide an excellent online manual if you get stuck. 

The other great thing about Eight-Voice, as with all Cherry Audio plugins, is it's affordability. $29 dollars (intro price) for a fully functioning version. So I would suggest downloading the demo version and check it out. Only difference is an intermittent burst of white noise with the demo version. 

Find out more and download the full or demo versions here:

Online user manual. 

If you enjoyed this post then why not consider liking my Facebook Page where you'll get all the latest news on future reviews, soundware, news and lots more!


The information contained within this blog post is offered on an informal basis and is correct to the best of my knowledge. I accept no responsibility for outcomes arising from the mis/interpretation or use of this information and/or associated download files. Always download files via security/scanning software. 

No comments:

Post a Comment