DSI OB-6 and Prophet-6 Modules

First came the keyboards, now desktop versions of the P6 and OB-6 are here! Dan ‘JD73’ Goldman checks them out…

Ifirst reviewed the Prophet-6 keyboard back in September 2015 and was impressed enough to go out and buy one myself, despite owning lots of other classic and modern polys. Since then, I’ve employed it on numerous productions where its high-quality sound has really come into its own. I’ve been using it for general polysynth duties such as warm pads and ’80s-style brass poly sounds (which it excels at due to its very upfront and punchy character, with plenty of high-mid presence and high-end sizzle), but I’ve also employed it for various mono duties – it can do very authentic, searing Minimoog-style leads and snappy, growling basses (the envelopes are very punchy, allowing sounds to cut like a knife). Classic poly sounds are the P6’s forté but that would be belittling its scope – it’s capable of going way beyond this.

To recap, the Sequential-badged Prophet-6 is basically a Prophet-5 made for the now, with an extra VCO (six instead of five voices), improved oscillator stability, the addition of a triangle sub oscillator, Slop (to dial in the randomness found in older analogues), a resonant 12dB HPF (in addition to the classic 24dB/4-pole LPF), two digital FX engines (with true bypass), an expanded ‘polymod’ section (polyphonic modulation, where modulation changes polyphonically) a transposable poly-sequencer and arpeggiator, plus comprehensive MIDI implementation.

The ethos with the P6 (and OB-6) is putting all the sound-shaping power directly under your fingertips, so pretty much every function has a dedicated knob/switch and there are no menus – just a basic three-digit LED to display patch numbers and various global functions. The P6 is a no-nonsense premium-sounding performance synth and already widely respected as a legit successor to the Prophet-5. For the intimate details on the Prophet-6 I refer you back to my review in FM297/on www.musicradar. com but here I think it’s more appropriate to update you with my thoughts after using it for a year.

The most important thing is that the sound is still hugely inspiring and engaging and few other current synths can touch its upfront, clear-cut yet earthy sound! The quality of the oscs is right up there with the best and it’s rich, creamy, gooey, sizzly and deep with virtually no background noise in the signal path. Warm-up time is fast and tuning very stable once you’ve calibrated the oscs a few times in different temperatures. The envelopes are punchy and very detailed sounding and the effects transform

Few other current synths can touch the Prophet-6’s upfront, clear-cut yet earthy sound

Once you hear a 12-voice Prophet-6 or OB-6 it’s very hard not to cave in if you have the cash

the sounds beautifully, placing them into many varied, yet always musically relevant contexts. Build quality is holding up great with everything still feeling and looking like new and DSI have also updated the OS regularly, with the latest update bringing several new velocity curves which have improved playability greatly.

The ‘downsides’ I’ve found are minor. Firstly, detuning via the Osc 2 fine-tune dial (and Slop) sounds too controlled for my liking – almost like the OS is pulling the tuning in too much and I’d like this loosened up a bit (as it has been on the OB-6), especially as the first few mms of travel on the Osc 2 detune dial don’t really do much, resulting in an ‘all or nothing’ type of detuning (I’d really like some more subtle range on that dial). Next up, as I mentioned in the original review, while I love the complete lack of menu diving (for gigging especially), having such a basic display is sometimes frustrating (ie, no patch naming). Yes there’s direct patch access (ten patches in front of you at any one time) but it’s still hard keeping track of your presets by number, though obviously this isn’t going to be getting changed as it’s a hardware limitation. Further, since the P6 launched, other analogue polys have entered the market with more comprehensive mod facilities, so the P6/OB-6 do look a little basic in terms of modulation facilities/ control, especially considering their price. For example, you can’t control either modules’ effects via a mod wheel, aftertouch or a pedal (as you can on the upcoming Behringer DeepMind 12 or on a Roland JD-XA); and a dedicated assignable second LFO is also something I wish the P6 had (I use this a lot on my JD-XA). Perhaps DSI could designate pitch wheel as another assignable source for controlling the effects or filter while still controlling the LFO depth from the mod wheel? Thankfully, the Polymod and X-Mod sections (on the P6M and OB-6M respectively) really help to take your sounds into other-worldly territory.

Now onto the P6 module specifically (and most of this can be

applied to the OB-6 module too). Well, it does what it says on the box! It’s quite literally the P6 (or OB-6) without the keyboard, made for desktop use, so the sound and all onboard facilities are 1:1 matched with the keyboard version(s), except for no wheels or keyboard! The build quality is universally high, with metal chassis/panel, solid dials/switches and wooden end cheeks (and wooden front trim on the P6M). Having a desktop version obviously takes up a lot less space than the keyboard version (though the unit itself is still pretty sizeable) and it’s a lot more portable too, so more viable for travelling/touring. The only downside is that the module is frustratingly just over an inch too wide to rack mount, even with the wood ends removed. I guess it would have meant making completely new internal boards and moving the connections (which would have bumped the cost even more).

The OB-6 module is built into the same size desktop enclosure as the P6 but with the styling, features, sound engine and knobs taken directly from the OB-6 keyboard (like the P6 I refer you back to my review in FM307/www.musicradar.com for the deeper details). It sounds exactly the same as the OB-6 (ie superb; like a modern Oberheim) and it works in exactly the same way too. Simply take a MIDI output from any controller board into the MIDI input and you’re off. What’s great is that, as both of these modules are internally and feature-wise the same as their keyboard counterparts, whatever changes you make on a P6 or OB-6 keyboard will be reflected exactly on the modules (you’ll need to dump any custom patches over to the module first in the exact same location(s) as on your keyboard, otherwise you’ll end up tweaking a different patch on the module). Thankfully patch dumping is easy, either straight over MIDI via bulk dump, or via MIDI-OX or Sysex Librarian.

If you’re after the poly-Oberheim sound, then the OB-6 module is currently the cheapest way to get a 6-voice poly happening, otherwise it’s down to buying an old Obie or linking several SEM modules together which would be way more costly (as they are around 1,400 euros each for a single voice SEM-Pro). So the OB-6 module (while still a significant outlay) is the most affordable current option for the polyphonic Obie sound. Yes, it’s a more modern/refined Obie sound than the Two Voice Pro I recently reviewed but with six voices, patch memory, a poly-sequencer and arp, plus the dual effect engines, it’s a very wellthought-out, nicely-specified and great-sounding machine that’s hard to argue with! It does sound gorgeous and significantly different to the P6 and P6 module, with the main differences being the slightly more drifty sounding oscillators, the square wave sub-oscillator and, more importantly, the distinctive statevariable 2-pole SEM-based, non-self oscillating filter which sounds juicy, gnarly and wiry, with a resonance control that can be pushed to maximum without losing too much low-end power. As a contrast, the Prophet’s filter goes way more crazy at higher resonance settings.

To conclude, after testing both synths extensively, for me it’s the Prophet that has proven to be more mouldable and versatile (as it slots into my mixes more easily), while the Obie oscillators/2-pole filter deliver more distinctive, edgy sounds which make the OB-6 stand out in any track/mix. Importantly, it’s genuinely hard to make either synth or module sound bad and the modules will please anyone who already has a packed studio (or is building a new set-up) but who wants that authentic Prophet or Oberheim polyphonic tone in a desktop unit. There’s very little to fault here and either module will have you grinning from ear to ear like a Cheshire cat. Great stuff again!