Monosynth vs. Polysynth: Which Should I Buy?

You’ve decided to buy a synth. You’ve considered things like type of synthesis (analog versus digital), size, number of keys, and connectivity. You’ve thought about new versus vintage and weighed the pros and cons of both. Maybe you’ve made a list of different manufacturers, visited shops to try them out, and watched countless hours of demos on YouTube. But now the million-dollar question: Which do you need, a monosynth or a polysynth?

We’ll walk you through everything you need to know to make an informed decision about which type of synthesizer to buy, including differences between the two types, features, benefits and drawbacks (including price), concrete applications, and what musicians are known for using each type of machine.

What's the Difference?

So what’s the difference between a monosynth and a polysynth? The clue is in the words. A monosynth can only play one note at a time (monophonic) and a polysynth can play many notes at a time (polyphonic). The number of notes a polysynth can play at any one time depends on the number of voices it has. Some polysynths have four, six, eight, or more. The number of voices is often indicated in the name, like the Korg Polysix or Behringer DeepMind 12 .

Note that the number of oscillators a synth has is different. The Minimoog has one voice but three oscillators, meaning you can sound three oscillators at the same time. The polyphonic Memorymoog also has three oscillators per voice. But with six voices, that allows for the possibility of 18 oscillators sounding at the same time. (The Moog One can get up to 48. Look out!)

Let’s look at a few more differences between the two types. Because a monophonic synthesizer can only play one note at a time, it will obviously lend itself to different playing styles than a polyphonic synthesizer. Monosynths are a natural fit for bass duties—and solos and portamento (the gliding or slurring between notes) is more common on monos than polys (although not strictly). Famous monosynths include the Moog Minimoog Model D, Korg MS-20, and Arturia MiniBrute.

Because they can play more than one note at a time, polys lend themselves to chords and more piano-like duties (a piano is of course also a polyphonic instrument, and as you can play all notes at the same time, it’s considered to be fully polyphonic). Because notes can overlap, legato playing styles are common with polys. Whereas a monosynth may abruptly chop off a note when another key is pressed, a poly will allow the note to continue—that is, until it has reached its maximum number of voices, at which point it will start to “steal” earlier notes. Examples of polysynths include the Sequential Circuits Prophet-5, Waldorf Microwave XTk, Yamaha DX7, and the Roland Juno series.


Given that polysynths can play more notes than a mono, why not just buy a poly? Why do monos exist at all? Let’s take a look at some of the benefits of each kind of synthesizer.

So why not just head straight to the polys? In a word: price. Polysynths can be very expensive. Every voice in a poly includes not only the oscillators but usually a filter and envelope. That means that for as many voices as a poly has, there are that many identical copies of the hardware inside. That can make them expensive.

"Every voice in a poly includes not only the oscillators but usually a filter and envelope. That means that for as many voices as a poly has, there are that many identical copies of the hardware inside. That can make them extremely expensive."

Monosynths are usually much cheaper than polys for this reason. And, relatedly, because they don’t require as much cabinet space for all that hardware, they can be much smaller. A small footprint might be exactly what your home studio needs. Lastly, as previously mentioned, monos excel at certain kinds of playing—particularly leads, solos, and bass lines. (Plus, if you find a great mono synth for your bass hand, you can then find a great poly to play melodies and harmonies with your other.) And, if experimentation and sound design is what you’re after, you’ll be in bleep heaven with a modular synth, which are almost exclusively mono.

But polys do have plenty of benefits. With all those voices comes the ability to play chords, and with all those keys, you can actually play with two hands (assuming you have enough voices). Musicians used to playing the piano may feel more at home with a poly with plenty of keys. This means you can also play some swell pads. (See what I did there? Swell-ing pads? I’ll see myself out.)

You can try, but the lack of harmony on a mono makes it hard to get good pads going. Some polys are also multitimbral, meaning they can play more than one sound at the same time and allow for doubling or keyboard splits (separate sounds programmed into different “zones” across the keyboard). Lastly, the polysynth owner can get the best of both words with unison mode, which stacks all of the synth’s voices onto one note, creating a kind of super mono.


Generalizations are all well and good, but you’re probably looking for some examples of practical applications for mono and polysynths. Let’s see how these two types of synths can be used in the real world.

  • Funk bass: As mentioned before, monos excel at bass. As Bernie Worrell and Herbie Hancock have aptly demonstrated, if you want to lay down a thick, funky synth bass line, you need a mono.

  • Solos: Because of their unique note triggering style, monos can be great for soloing too. Rick Wakeman may be known for his Mellotron but all those wiggly Yes solos were pure Minimoog Model D.

  • Sequenced techno bass: What would techno and house be without the Roland TB-303 bass line synth? Although you can’t play it in the traditional sense, it is still very much a monosynth. Its influence continues in modern machines like the Korg Monologue and Arturia MiniBrute 2S.

  • Sound design: Sometimes you just want to play with sound and there’s no better platform than Eurorack for pure synthesis fun. Zaps, whooshes, atonal percussion, and more are all just a few cables’ length away. Watch out, though. When we said before that monos were less expensive than polys we definitely were not talking about modular synths.

  • Jazzy chords: If you’re doing Detroit techno or soulful R&B, you’re going to need something with a high voice count. Complex, two-handed chords will only be possible on something with lots of voices, like a Dave Smith Instruments Prophet Rev2 or, if you can afford it, a Moog One.

  • Ambient pads: Lazy, evolving pads. Glassy, digital textures. Rivers of sonic bliss. These kinds of all-encompassing harmonic sound baths are best made with a polyphonic synthesizer. If you make ambient or New Age music, a poly is a must.

  • Band backing: With the sound of the ‘80s back in fashion, synthesizers have begun to appear in bands again. To really flesh out your band’s sound, you’re going to need a poly like a Roland Juno-60 or Korg Polysix. Or even an Oberheim if you’re aiming for that Prince and the Revolution sound.

  • All-in-one tasks: Not all of us can afford a room full of synths like our favorite YouTube synth stars. Sometimes you have to make do with one synth. If you need to jam econo, a multitimbral poly, preferably with a built-in sequencer, is just what you need. Check out Satoshi & Makoto, who make the most of a single Casio CZ-5000.

Final Thoughts

We hope that this guide has given you some things to think about. It may be difficult to decide on a mono or poly, given the sheer variety of instruments available. We recommend considering what your needs are first. How do you plan to use your new synth? Do you want something that will do everything, or are you looking for something to add just a little spice to an existing computer-based setup?

If we may, we’d like to recommend a compromise: the Korg Minilogue. Although it’s a four-voice poly, it’s very affordable, and it has a mono mode so you really get the best of both worlds. It’s also rather compact.

Whichever way you end up going—mono or poly—you really can’t lose because no matter what, you’ll have a new synthesizer to play with.

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