One of the things you should know about a synthesizer before you buy it is if it is monophonic or polyphonic. Monophonic is the simplest type of musical texture characterized by having a single melodic line without accompanying harmony or counterpoint. Polyphonic, on the other hand, is the type of musical texture with more than one independent melody occurring at the same time. This simply means that with a monosynth or monophonic synthesizer, you can only play a single note at a time. With a polysynth or polyphonic synthesizer, you can play several notes at a time.
A mono synth does not necessarily mean it only has one oscillator that generates the raw sound signal. It can have more than one such as in the case of the Minimoog that has three VCOs or Voltage Controlled Oscillators with the oscillator 3 functioning as Low-Frequency Oscillation (LFO) and for frequency modulation effects. It is monotimbral, which means that if you press a single key, it can generate only one timbre at a given pitch. This synth has a 44-note keyboard and uses analog subtractive synthesis to create a unique sound with a 24dB/oct 4-pole low pass filter and ADSD envelope generator. This is said to be the first synth that was sold in stores.
Other popular monosynths include the Roland TB-303 and the Korg Prophecy. The synth without a keyboard that was released by Roland Corporation was monotimbral. It had a single oscillator generating waveforms such as the square for a “buzzy” sound and sawtooth for a “hollow” sound. Although it failed to replicate the bass guitar that it was designed for, it became the foundation for techno, house, and other electronic dance music genre. The monotimbral Korg Prophecy has 37 keys with Aftertouch- and velocity-sensitive keyboard, and it offers physical modeling synthesis with four attenuators that lessen the power of the signal without distorting the waveform. It may be one of the earliest virtual analog synths, but it has powerful synthesis capabilities.
Although monophonic synthesizers are considerably cheaper than polysynths, it does not mean it is inferior and not worth looking at. They are great for solos or leads, and it can create thick bass lines. As technology develops, electronic musical instruments do so as well. There are many new monosynths that are revivals of the classic with improved and better quality specs and features.
Behringer Synthesizer (TD-3-RD)
This desktop bass synth has authentic reproduction of the classic analog circuitry for groove and bass sounds. It has a single VCO with the pulse and reverse‑sawtooth waveforms modified by the 24dB/octave filter with low‑pass filter and resonance at the cutoff point. With its onboard 16-step and seven-track sequencer, you can create and program up to 250 patterns using Step mode or Keyboard mode. It also has an arpeggiator, decay control, envelope generator, and distortion effects.
Although it is monophonic, it can link or combine several synths for 16-voice polyphony. The Behringer synth (TD-3-RD) dimensions are 2.2 x 12 x 6.5 inches, 11 controls, and 28 switches to access the essential parameters. Its OS requirement for MAC is OS X 10.8.5 or later, and for PC, it is Windows 7 SP1 or later.
Korg MS20 Mini Semi-Modular Analog Synthesizer
This new analog synth from Korg is actually the mini-version of the classic Korg MS-20 monophonic synthesizer that was first released in 1978. It has the same look but smaller, just 86% of its original size. It can reproduce the same distinctive sound as the original because it has retained the Korg35 circuit.
The developers of MS-20, namely Fumio Mieda and Hiroaki Nishijima, added a USB port and MIDI input. Still, its MIDI support is limited to note data, which means that when connecting the MIDI input of the MS20 mini to DAW or the keyboard’s MIDI output, it will receive the data then produce the sound. Their goal is for users to have an appreciation of how the sound changes in real-time.
The Korg MS20 Mini Semi-Modular analog synth will enable you to create your own unique sounds from scratch. Some of it specs include a mini-keyboard with 37 notes for three octaves, two VCOs, VCO master control and VCO mixer, voltage-controlled high pass filter and low pass filter, two envelope generators, and modulation generator for several waveforms including positive/negative sawtooth, triangle, square, and wide/narrow pulse. Its features include 2 VCO with ring modulation, 2 Voice-Controlled Filter (VCF), 2 Voice-Controlled Amplifier (VCA) with less noise, 2 Envelope Generator (EG) with hold and delay, and one LFO.
Korg Synthesizer, 25 Key (MONOLOGUEBK)
Korg’s 25-key monologue synthesizer has an engine or a monophonic analog synth circuitry that is based or similar to that of the Korg Minilogue. It has two oscillators, and each has three waveforms with waveshaping control, Sync, and Ring Modulation. There are three envelope generators with attack and decay controls for sound shaping as well as LFO for shape, pitch, or filter cutoff. The built-in OLED oscilloscope provides visualization of the waveforms as they are altered or shaped in real-time. You can save up to 100 programs for easy recall.
The monologue synth is fully programmable. It has 25 slim velocity-sensitive keys from E to E, 23 dedicated controls for convenient parameter access, and a slider to control various parameters, 32 settings for microtuning, and 16-step monophonic sequencer. It has USB MIDI, MIDI, and AudioSync connectivity.
IK Multimedia UNO Synth Portable Monophonic Analog Synthesizer
The UNO monophonic analog synth from IK Multimedia is compact, portable, and easy to use with its simple multi-touch keyboard that has sound editing parameters including the oscillator controls to generate the sound and set the waveform for each oscillator as well as tuning each one; the filter controls to give it color with its bandpass, lowpass, and highpass modes; the envelope controls for the filter and the amplitude; and the LFO controls. There are six performance buttons for easy and instant access to modulation effects such as the dive, scoop, vibrato, wah, tremolo, and then the hold button to keep the note sound after letting go of the key.
There are 100 presets (80 0f which are rewritable), arpeggiator with 10 arpeggio modes and 4-octave range, sequencer with 20 parameters for each step, and a selection of 13 scales. It has two independent VCOs that can produce octave and pad-like interval sounds, a noise generator, resonant voltage-controlled filter, and a voltage-controlled amplifier.
The IK Multimedia UNO synth has a powerful and versatile analog sound module. It is easily integrated into DAW and other audio tools on PC/MAC computers, even without MIDI interfaces.
Novation Bass Station II Analog Mono-Synth
The Bass Station II analog mono synth that is geared to produce heavy-hitting huge bass sounds comes with a new acid filter that can get squelch-like sucking sound to add to the classic filter design of the original with lowpass, highpass, and bandpass modes at 12 or 24dB slopes, which would then give two distinct sounds. It has dual primary oscillators that can be hard-synced for tighter punchy tones, sub-oscillator with sine, square, and pulse waveforms, a built-in arpeggiator with 32 rhythmic patterns and control over the octave range, and built-in step sequencer for more expressive sound creations.
The Novation Bass Station II analog mono-synth is a keyboard synth with 25 keys for synth action and Aftertouch, pitchbend and modulation wheel, 64 factory presets, and MIDI and USB connectivity.