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Dave Smith Instruments Mopho x4 Synthesizer Keyboard

$690.00 Price Tier: Standard

4.5 (15)

3 Reviews

Find out who is using Dave Smith Instruments Mopho x4

3 community setups

32 wishlisted

70 saved

Page last updated May 28, 2026

Pricing and availability

We compare 600+ stores and found this item at 1 store. Prices updated May 28, 2026.

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Price

5.0 (8)

$690.00 8 available Used

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Average Price: $690

Standard/Professional

$500

$1501+

Price Tier

In the Synthesizers category, Dave Smith Instruments Mopho x4 Synthesizer Keyboard is priced in the Standard/Professional range. This is quality gear at a fair price point, suitable for beginners, hobbyists, and pros alike.

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Description

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Unleash your sonic creativity with the Dave Smith Instruments Mopho x4 Synthesizer Keyboard, a powerhouse of analog synthesis wrapped in an elegantly compact design. Perfect for both studio and live performances, this versatile instrument offers 4-voice polyphony and a 100% analog signal path, delivering robust and dynamic sounds that are sure to inspire any musician. The Mopho x4 is equipped with 44 semi-weighted keys featuring velocity and aftertouch, providing expressive control over your compositions.

At the heart of this synthesizer are two analog oscillators and two sub-octave generators per voice, complemented by a genuine 2/4-pole-selectable Curtis lowpass filter. Dive into sound design with three 5-stage envelope generators, four LFOs, and a 16 x 4 step sequencer, all of which invite you to explore new sonic territories. The relatchable arpeggiator and extensive modulation options further expand your creative possibilities, allowing for intricate textures and sequences.

For those looking to grow their sound, the Mopho x4 offers easy expandability. Connect additional Dave Smith Instruments like the Mopho, Tetra, or Prophet '08 through the Poly Chain port to transform your setup into a 16-voice analog synth monster. Born from the vision of analog synth legend Dave Smith, this instrument not only carries a rich heritage but also pushes the boundaries of modern music-making. Whether you're crafting behemoth basses, celestial pads, or intricate leads, the Mopho x4 stands ready to bring your musical visions to life.

Key Features:

4-voice polyphony with two analog oscillators and two sub-octave generators per voice
44 semi-weighted keys with velocity and aftertouch
Genuine 2/4-pole-selectable Curtis lowpass filters
Three 5-stage envelope generators and four LFOs per voice
Relatchable arpeggiator and a 16 x 4 step sequencer
USB 2.0 for bidirectional MIDI communication
Expandable via Poly Chain port
Designed and manufactured in San Francisco, USA

Product specs

Brand	Dave Smith Instruments
Model	Mopho x4 44-Key 4-Voice Polyphonic Synthesizer
Finish	Black with Wood Sides
Year	2013 - 2018
Made In	United States
Categories	Analog Synths, Keyboard Synths
Analog / Digital	Analog
Key Size	Full Size
Keyboard Action	Semi-Weighted
MIDI I/O	MIDI Input, MIDI Output, MIDI Through, USB MIDI
Number of Keys	44 Keys
Polyphony	4 Voices

FAQs

Is the Dave Smith Instruments Mopho x4 Synthesizer Keyboard polyphonic or monophonic?: The Mopho x4 is a polyphonic synthesizer with 4 voices, allowing you to play chords and complex harmonies.
What kind of synthesis does the Mopho x4 use?: The Mopho x4 utilizes analog synthesis, providing warm, rich tones characteristic of classic analog synthesizers.
How many keys does the Mopho x4 have and what is the action type?: The Mopho x4 features a 44-key keyboard with semi-weighted action, offering a responsive feel suitable for expressive playing.
Does the Mopho x4 Synthesizer have USB MIDI connectivity?: Yes, the Mopho x4 includes USB MIDI connectivity, making it easy to integrate with your computer and digital audio workstation.
Can the Mopho x4 be used as a MIDI controller?: Yes, the Mopho x4 can function as a MIDI controller, allowing you to control other MIDI-compatible devices and software.
What are the dimensions and weight of the Mopho x4 Synthesizer?: The Mopho x4 measures approximately 18.65″ L x 11.1″ W x 3.6″ H and weighs under 10 pounds, making it portable for live performances or studio use.

Videos

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Sequential

Mopho x4 Demo- Dave Smith Instruments

Sequential

DSI Mopho Keyboard - SonicLAB Review

sonicstate

Mopho x4 Synthesizer Keyboard Introduction

Sequential

DSI Mopho x4 Demo with Peter Dyer

Sequential

DAVE SMITH INSTRUMENTS Mopho x4

session

An Evening with Dave Smith Instruments' Mopho X4

JediSid

Dave Smith Instruments Mopho X4 "More Analog Pads & FX" Synthesizer DSI

Rik Marston Official

Dave Smith Mopho x4 in 10 minutes (no talking)

Mr. Card

Why I love Dave Smith Mopho x4? ❤️ (sound demo)

Mr. Card

Dave Smith Mopho x4 ► Sound Demo [1 HOUR]

Mr. Card

Reviews

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PROS

Sound significantly bigger than similar models
Durable, performs well through shows and recordings
Fully analog with a great range of controls and sounds
Built like a tank, ideal for road use
No menu diving, intuitive knob control
Compatible with polychaining, enhancing performance flexibility
Offers a gritty, cutting sound that stands out
Highly capable modulation matrix for diverse sound crafting
Can produce atmospheric sounds with the right effects
Considered great value for an analog polyphonic synth

CONS

Onboard sequencer powerful but not user-friendly
Modulation sources may require time to understand
Deep features can be difficult to access live
Some users find pads lacking without additional effects
Workflow not the most natural, requires practice

Owner Insights

We analyzed real musician discussions from forums and Reddit to find what players love, question, and tweak about Dave Smith Instruments Mopho x4 Synthesizer Keyboard.

Features and functionality

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The Mopho X4 is compact with a 3.5-octave range, thanks to the mod and pitch wheels not being placed next to the keybed.
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Sequencer offers powerful note and modulation tracks but requires navigating a small LED readout, which can be unintuitive.
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The Mopho x4's filter resonance can be used creatively as a high pass, offering unique sound design possibilities that stand out in a mix.
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The feedback and sub oscillator are favored for their impactful sound, particularly in creating presets like toy piano with added sub oscillator and feedback.
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Build quality

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The keybed is noted for being solid and well-made, contributing to the overall robust feel of the instrument.
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User experience

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Some owners miss dedicated controls for each envelope and oscillator frequency, leading to potential interest in upgrading to a Rev2 for better control.
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0 0

The Mopho X4 isn't ideal for beginners due to its multi-function buttons and menu navigation.
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Owners appreciate the synth's size and limitations, which encourage creative restraint and help prevent overcrowded mixes.
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Setup and maintenance

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Jumpy encoders and random filter value changes were noted issues, potentially fixable with firmware updates or deoxit cleaner.
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Use cases and applications

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Ideal for mobile setups; one user replaced their Rev2 with the Mopho X4 for easier transportation without significant sound compromise.
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The Mopho x4 excels in creating strong, cutting sounds that are effective in a band setting, though it lacks versatility for softer tones.
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0 0

The Mopho x4 is frequently used for brassy pads and leads, but it doesn't offer a large sweet spot for sound exploration.
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Comparisons

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The Rev2 offers more modulation routing, onboard DSP effects, and an added sub oscillator, providing a richer sound than the Mopho X4.
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0 0

Mopho X4's programming depth surpasses Behringer Pro-800, though the latter is praised for sound quality.
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0 0

While the Mopho x4 can dial in classic Prophet-esque sounds, its "Curtis fizzy" filter may not appeal to everyone compared to other Sequential synths.
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Value and pricing

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Mopho X4's $850 price with a case is close to Prophet 08 territory, which offers more voices and features.
Source

Add review

4.5 out of 5

Based on 3 Reviews and 15 Ratings

5 star

4 star

3 star

2 star

1 star

jimmarchi1

41003

almost 7 years ago

they shouldn't have discontinued this

bang for buck... and this has THE sound... its gritty and cutting... Its highly playable... deeper features (and even a few standard features) can be a bitch to access which makes live tweaking patches a pain. Still, it sounds great. My favorite CEM synth on a chip synth hands down, sorry prophet 08 and rev2.

Roles:

Guitarist Bassist Keyboardist

Genres:

Electronic Orchestra Alternative rock

From Gear Setup

jimmarchi1

41003

6 years ago over 6 years ago

I really love this synth

jimmarchi1

41003

6 years ago about 6 years ago

I cooled on this synth a little and then rediscovered its might doing my Westworld score. It may not be as warm and inviting as the prophet 600, but its got that sound and its punchy and complex, big soundstage, perfect for horns, squealing glassy textures, robot noises....

stijncole

over 11 years ago

Swiss army poly synth.

Thsi must be the cheapest polyfonic analog synth on the market. But it also sounds amazing, there is a lot under the hood, but you can get a software companion for it, wich is great. It's great on pads, bass and leads.

manolarra

162

over 9 years ago

Analog

Great synth, it has nothing to envy in terms of features and sound to more expensive synths. Fat sounds and very well utilized leads. And the versatility of the 4 voices is a plus.

This review has been translated automatically into English. See original