Dave Smith Instrument 'Mopho' Analog Synth

[Khazul]

Dave Smith Instruments ‘Mopho’
Mopho at DV
Mopho at DSI

I was invited into the Digital Village West London store to test the Mopho. DV very kindly set up a mac-book based workstation with Ableton Live 7 and a small controller keyboard and left me to play for a couple of hours.
Knowing that trying to get a good meaningful and comparative sense of the sound character of this synthesiser would be all but impossible outside of my own familiar studio and monitoring setup, I opted to take a pair of headphones with me. In the end I opted for my AKG-181 DJ cans (rather than my AKG-240 or 271) as I am more used to hearing both other music and my own music on them than any others headphones I have and they have the most solid and predictable bass response of the three, and have the advantage of good ambient sound isolation.

My personal main interest in an analogue mono-synthesiser is in what it can do for me for mainly bass sounds, glitch noises and leads, mainly within the genres of trance, progressive house, electro house and tech house.


Overview
The Mopho is a low cost fully analogue signal path monophonic desktop synthesiser with (I believe) fully digital control of oscillators and modulation that at first glance appears to be based upon a single voice of the Dave Smith Prophet 08 with the addition of sub-oscillators, lending it huge potential as a bass focussed companion synthesiser . Indeed I believe it is possible to use a Prophet 08 as a control surface for the Mopho due to MIDI compatibility of parameters that are common to both.

The unit itself is a small metal case finished in bright yellow with endless rotary controls for parameters, and volume control and connections for MIDI in and out, a mono audio in, stereo audio out and headphones and a small dual line display for visualizing parameters and global settings.

It is easily small enough for to conveniently placed on a control free part of the top panel of most keyboard synthesisers, and possibly light enough to safely ‘Velcro’ in place.


(Reproduced with Kind permission from Dave Smith Instruments)


Synthesis
The Mopho basically follows the usual architecture for a subtractive analogue synthesiser as illustrated in the diagram below, with the interesting addition of sub-oscillators and a feedback path from the audio out to the filter input when external audio is not being used. What the diagram doesn’t show however is the very extensive modulation routings that this synthesiser provides.


(Reproduced with Kind permission from Dave Smith Instruments)

Oscillators
The Mopho has two oscillators which appear to be digitally controlled along with a noise generator. The digital control means what while the oscillators are still analogue, they are digitally synchronised and so yield the frequency stability and accuracy of a digital oscillator, but with the waveform characteristics of an analogue oscillator.

One of the charms and sometimes annoyances of a fully analogue synthesiser is frequency fluctuations and temperature dependencies of the oscillators. With the digital control you lose this subtle randomness, potentially making the synthesiser quite sterile sounding when using more than one oscillator. However there is an ‘Osc Slop’ parameter that re-introduces these subtle frequency fluctuations when they are required.

Each oscillator can generate saw, triangle or variable pulse, however unlike many analogue synthesisers, there is no option to mix between saw and variable width pulse waves, only a mix of triangle and saw waveforms.
Until this point, the oscillators appear to be identical to those in a single voice of the DSI Prophet 08. Where the Mopho goes beyond the Prophet 08 and can thus yield its own distinctive timbres is with the additional of a sub-oscillator to each of the two oscillators, these yield a square wave, one octave down for oscillator 1 and two octaves down for oscillator 2.

Filter
The Filter section allows for two modes: a self oscillating 24dB/Octave low pass filter and a non self oscillating 12dB/Octave mode. There is a parameter to control the keyboard tracking of the filter thus it is in theory possible to use the 24dB/octave filter as a third sine wave oscillator, however on the test unit the keyboard tracking seemed to be far enough off such that this use wasn’t practical. However I learned later that there are ‘Hidden’ calibration functions accessible through holding buttons on the front panel for calibrating waveform generation and filter tracking.
When not using the external audio input, audio from the left side output is fed back to the oscillator mix via a level control before the filter allowing for subtle saturation to screaming distorted resonant lead sounds. Lower levels of feedback I found were excellent for adding a little grunge to bass sounds, while high levels are great for cutting leads. Additionally you can apply audio modulation to the filter cut-off frequency which again is great for adding dirt.

Modulation
The Mopho makes available 4 LFOs and 3 envelopes and 4 slot general modulation matrix as well as individual modulation destinations for the mod wheel, after-touch and several other common MIDI performance controls allowing for the generation of very complex evolving sounds. Indeed some of the evolving pad like sounds that can be programmed puts many polyphonic digital synthesisers to shame with the addition of external effects and despite only being a monophonic synthesiser.

While I believe the entire modulation section is actually entirely digital being generated by software from the onboard DSP, the envelopes certainly seem to have a very snappy feel to them with a nice natural analogue-like decay and release curves that I often struggle to emulate on many digital synthesisers I have programmed. The only slight minus from the digital modulate is its potential for stepping, for example, the filter is controlled in ½ semi tone steps, however I didn’t get time to evaluate this and didn’t notice any stepping while programming sounds on it.

The envelopes are all 5 stage: delay (which controls the delay time between triggering and the attack starting), and then the familiar attack, decay, sustains, release. The envelopes also have a velocity parameter that controls the level of the envelope according to key velocity and an envelope amount parameter that controls the effect upon a modulation destination. Two of the two envelopes are hard wired to the filter and amp section respectively leaving the third envelope assignable.

The LFOs provide ramp, reverse ramp, triangle, square wave and a random sample and waveforms at cycle lengths that can be set in one of three ranges: very low, yielding cycles 30 seconds a cycle up to 8Hz, then in semi-tone steps up to 261HZ (Middle C), then finally in various dividers of the sequencer clock. Each LFO has its own assignable destination.

The general purpose modulation matrix slots appear to be able to accept as a source any of the envelopes, LFOs or common MIDI performance controls as well as key velocity, key note or audio in held level, envelope follower or noise and appear to be able to control any parameter in the remainder of the synthesiser.

Sequencer, Arpegiator and other control Functions
In the limited time I had, I didn’t get a chance to play with these functions at all, and that was partly due it being a rather fiddly time consuming process to program these functions from the front panel, however I’ll briefly summarise what is available.

The Mopho features 4 x 16 step sequencers and an arpegiator that share a common clock. The clock be generated from an internal clock, or synchronised to an external MIDI clock with various dividers that also include a couple of fixed swing presets.

The arpegiator supports the usual up, down, up down and an assign mode that follows the order of played notes.

The step sequencers each have their own modulation destination, and as with the other internal modulation sources (LFOs and envelopes etc) additional destinations can be affected using the general purpose modulation matrix slots. As the stes include note information, then these can be used for note sequencing as well as modulation sequencing.

The sequencer can operate in a variety of modes from key triggered, key gating, and stepping triggered from either a note on message, the push it button, or interestingly the level on the external audio input.


In Use
Hands On
For a box with so few controls, programming of basic synthesiser parameters actually isn’t that bad, but certainly does not compare to the convenience of programming a knob laden desktop or keyboard as may be expected.

There are endless rotary knobs dedicated to the control of filter cut-off, filter resonance, attack and decay + release on the three envelopes, these yield basic immediate sound shaping. For all other parameters you need to use a combination of the assign button and the four assignable rotary knobs. In general, once a patch is programmed, you probably will not need to use the panel controls at all, and instead use the performance controls of your keyboard (mod wheel, foot controller/expression etc) for which extensive modulation routings are available.

In starting to tweak some of the presets, I came across my first minor gripe with the filter cut-off rotary – it really is only a programming tool in that you cannot performance fast sweeps with it due to requiring several turns to sweep its entire range. This to a lesser degree is also true of many of the other controls once assigned. The positive side of this is that setting a parameter to a very specific value is quite easy.

Programming other parameters is basically a case of hitting the ‘Assign Parameters’ button, then turning each of the four ‘Assignable Parameters’ knobs to select the required parameter on each, then hitting the ‘Assign Parameters’ button again, meaning you can basically edit four parameters at a time. While a bit fiddly and time consuming, I did manage to learn my way around the synthesiser and program a variety of useful patches in the two hours I spent with it, so it is certainly easy to learn and navigate, however by the end of it I was having craving for a software editor. This was largely the reason I didn’t get to delve into the step sequencers as while you can program them 4 steps at a time its rather time consuming.

I have since learned however that there is a software editor for both Mac and Windows is available as a free download.

In programming patches I was struck by how little I found the increment and decrement button useful. I actually almost wish that you could have a few banks of assignable knobs and then use these buttons to navigate the banks to keep say sixteen (or more) parameters close to hand rather than just four as I think such a change could significantly speed up patch programming without increasing cost. That said, while programming is a bit fiddly, it is easy to learn and navigate once you get used to it, so on balance I think Dave Smith has done a good job in creating an useful programming interface from so few controls.

Via MIDI
As a desktop synthesiser, users will want to control many parameters in real time via MIDI, particularly, for example, filter cut-off and resonance, feedback, envelope decay/release, envelope amounts, LFO frequencies and amounts etc.

When programming parameters from the panel you start to notice the ranges of the parameters. While most fit into the MIDI CC range of 0-127, there are several notable parameters that do not: filter cut-off, envelope and LFO destination amounts for example, thus NRPNs or Sys-ex appear to be required for complete remote control. In the case of the filter cut-off, then there is an alternate CC available that can provide a filter offset which covers most performance needs, otherwise consider programming common MIDI performance CCs into a patch’s controller matrix. This caught me out slightly when working with Ableton Live and I was initially wondering why the filter cut-off only covered a part of the available frequency range, however once noted it ceases to be a real issue and is easy to work around. If your sequencer only supports MIDI CC and NRPN or Sys-ex (for example, Ableton Live), then you will need to take this approach.

The Sound
When reading the following, please note I was using a pair of headphones that I normally use for DJing. While they are good headphones with a wide frequency response and good bass response, they are not at all the normal listening environment I use.

The oscillators with the filter wide open seem reassuringly fat (caveat – while listening on the headphones I used), even with just a single oscillator in isolation. If you are used to digital synthesisers, then you immediately notice the smooth pleasing overall frequency response. Smooth clear high end, and nice cosy warmth to the low end.

My initial impression of the sound character of the two filter modes that the overall sound is actually quite energetic and cuts through other sounds well. Adding resonance yields a nice progressive change in sound character without screaming at you so you probably won’t need to be scrambling for a compressor/limiter with high resonance settings as with many digital synthesisers.

Some of the more ‘stabby’ and lead sounds I tried programming had a very strong sense of energy to them with both filter modes, whereas the various bass sounds I programmed where very full without feeling the need to crank up the sub-oscillators. However with the subtle addition of the sub-oscillators, I could easily see this producing floor crumbling bass sounds.
With the additional sub-oscillators, you can actually program very energetic and convincing single key house stab-chord type sounds by detuning oscillator 2 by a few semitones and using the sub-oscillators to fill in below.

Summary
My main analogue synthesiser for reference is my Studio Electronics ATC-X. In comparison, the Mopho certainly seems a far more predictable and well behaved synthesiser and generally sweeter sounding, in particular you notice everything is perfectly accurate and well under control, unless of course, you choose to introduce chaos. With the addition of the sub-oscillators and the extensive modulation sources and routings the Mopho actually turns out to be a far more flexible synthesiser and I suspect also far easier to mix with. Having only the two filter modes does not feel like a limitation, and the filters are so different that each yields a quite separate spectrum of timbres. For the tight sounds demanded by a lot of modern music I rather like the Mopho, and much more so than my brief encounter with the Prophet P08 and Moog LP. In many ways, I almost wish that Dave Smith would produce a Prophet 08+ that added the extra features of the Mopho back into the polyphonic synthesiser that spawned it as they really do add a lot to the range of timbres you can produce, and not just for bass sounds.

Ignoring the price, the obvious common alternative synthesisers are the Moog LP and SE ATC-X. I actually think I prefer the Mopho as a synthesiser engine over these which is surprising as I was never impressed enough with the Prophet 08 to actually want to buy one (though the UK price had a lot to do with that). It seems the simple addition of the sub-oscillators has very much won me over as in an analogue monophonic synthesiser in my context of house music production, great bass sounds is my number one interest and the Mopho certainly delivers and anything else I find it great for it is a bonus. As stated above, this is with the caveat of not being able to compare them side by side. And of course it’s a matter of personal sound character taste too.

Looking at the price again, a combination of a good controller keyboard and a Mopho make for a very attractive synthesiser. Additionally the company who produce the software editor will apparently soon release a VSTi plugin version (for extra cost) yielding some of the production convenience of software synthesisers and the Access Virus TI.

Pros
• Very good value for money
• Warm ‘ballsey’ sound character
• Easy to navigate once you get used to it
• Excellent analogue bass synthesiser
• Very flexible modulation and control
• Great potential for the ‘bizarre’ through-audio processing
Cons
• Fiddly to program on the panel, however the software editor should change this
• I personally prefer a rack format, however that would probably push up the cost
Price
Approximately 320UKP

Acknowledgements
Thanks to Digital Village for the opportunity to test out the Mopho at their West London store, and especially to Paul 'Modz' for organising this.
Thanks to Dave Smith Instruments for permission to reuse photos and diagrams in this article.

[sureno]

very professional review K
how did you get on with the endless encoders?

[Khazul]

Originally Posted by sureno

very professional review K
how did you get on with the endless encoders?

Thanks

The endless rotataries make for a good patch programming interface IMHO, however I personally have never really liked them as 'performance' controls.
In this case that is partly because they seem calibrated for precise programming rather than the rapid changes often needed in real time performance control, but thats what a mod wheel and pedals etc are for on your keyboard.

With the Mopho you dont actually need to use the on-box controls as performance controls simply because there are such good options for routing of common performance orientated MIDI CCs, which IMHO is an excellent design descision that I wish more synth manufacturers would consider, for example, when programming my TI, I'll often end up using up alot of its mod matrix slots just for routing performance CCs. With the Mopho (and I assume P-08 as well), these CCs have their own dedicated routings, so you can keep the general slots for adding sound complexity.

So on balance, I think that DSI chose to have these controls as precise programming orientated controls and in the context of the rest of the design (ie the available CC routings), I actually think they made the right choice, even if most users will want to try and use them as performance controls to start with.

If you are more of a tweaker than a keyboard player, then I would still suggest that you program patches with the aim of 'performance' from your sequencer in mind as this (IMHO) makes subsequent editing either in the Mopho, or in your sequencer easier.

[modz1]

Really excellent stuff K.!
And here's some pics of the maestro at work..

[sureno]

i see you have the makings of a track of some sorts in live?
any chance of hearing it?

[Khazul]

Originally Posted by sureno

i see you have the makings of a track of some sorts in live?
any chance of hearing it?

It was just a few rough clips that I had recorded to try out some of the MIDI control from Live, mainly I was just playing on the keys while tweaking though

BTW - I quite like that AKAI controller - it aint bad at all

[sureno]

Originally Posted by Khazul

It was just a few rough clips that I had recorded to try out some of the MIDI control from Live, mainly I was just playing on the keys while tweaking though

BTW - I quite like that AKAI controller - it aint bad at all

it's great, i got mine from west london DV
it has lovely solid keys and the pads have a quality feel.
also works beautifully with logic

[JAYDMF]

Bit late on reading this but a question to K' would you rate this for use for heavy bass in Breaky DnB etc ?

[Khazul]

If its the sounds Im thinking of then there are usually four ways of making them:

1. Stack up loads of slightly detuned oscs - Virus, JP80xx, Radias are all good for this.
2. Stack up some detune voices - anything withn unison and/or layering willl do the job
3. Start with a pair of fat square osc (not some wimpy VA osc) and slowly modulate the PWM - this works great on the mopho and actually any analog I have used.
4. Start with a pair of oscs and use a pair of fast LFOs to modulate the pitch a tiny bit - also doable on the mopho.

I dint try making any of these kids of sounds while I was playing with it, but I would expect the result to be just plain brutal if you combine 3 and 4 above and dial in the one or both of the sub-oscs (PWM to make the main oscs move, the pitch mod to give a little bit more and make the sub oscs move as well).

[JAYDMF]

Originally Posted by Khazul

If its the sounds Im thinking of then there are usually two ways of making them:

1. Stack up loads of slightly detuned oscs - Virus, JP80xx, Radias are all good for this.
2. Stack up some detune voices - anything withn unison and/or layering willl do the job
3. Start with a pair of fat square osc (not some wimpy VA osc) and slowly modulate the PWM - this works great on the mopho and actually any analog I have used.
4. Start with a pair of oscs and use a pair of fast LFOs to modulate the pitch a tiny bit - also doable on the mopho.

I dint try making any of these kids of sounds while I was playing with it, but I would expect the result to be just plain brutal if you combine 3 and 4 above and dial in the one or both of the sub-oscs (PWM to make the main oscs move, the pitch mod to give a little bit more and make the sub oscs move as well).

Nice one dude. everything i have atm is just pretty crap for those sort of sounds (with the exception of Massive and emulator thats just arrived but they still dont have a particularly "fat" character) so i think this could well be on the short list of essential synths

[Khazul]

If you want to stick with softies, then Sylenth1 might also be excellent as you can just dial in as many detuned oscs as you need, however it doesnt have continuously variable pulse width, so no PWM, though you can get similar result throughs other means with it and some of the presets include some quite nasty d&b style basses.

Definately one of the fattest sounding softies, though the mopho is still fatter sounding and more punchy from a pair of oscs.

[JAYDMF]

Originally Posted by Khazul

If you want to stick with softies, then Sylenth1 might also be excellent as you can just dial in as many detuned oscs as you need, however it doesnt have continuously variable pulse width, so no PWM, though you can get similar result throughs other means with it and some of the presets include some quite nasty d&b style basses.

Definately one of the fattest sounding softies, though the mopho is still fatter sounding and more punchy from a pair of oscs.

Thats what im after punchy fat analogue. Been debating between the mopho and the evolver mainly. Absolutly love the evolver but its a bit out of my price range right now. soo much to buy and so little money. just really want something that is fat as hell as i have komplete 5, emulator x3, albino (V1) so plenty of soft synths. also got the blofeld and the morpheus for digi shenanigins just need something uber punchy. i think for the price this has got to be the boy.