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Sequential Circuits Pro One Synthesizer

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$2,000.00 Price Tier: High-end

5.0 (24)

2 Critic Reviews

7 Reviews

This product is Vintage or Discontinued

Find out who is using Sequential Circuits Pro One

2 community setups

43 wishlisted

87 saved

Page last updated Jul 04, 2026

Pricing and availability

We compare 600+ stores and found this item at 1 store. Prices updated July 4, 2026.

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Reviews

Price

5.0 (8)

$2,000.00 21 available Used

View Deal

Average Price: $2,000

High-end/Boutique

$500

$1501+

Price Tier

In the Synthesizers category, Sequential Circuits Pro One Synthesizer is priced in the High-end/Boutique range. This premium gear is built to very high standards and offers premium features.

Budget

Standard

High-end

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Description

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Introducing the Sequential Circuits Pro One Synthesizer, a powerful monophonic piece of kit from the golden era of analogue synthesizers. With its dual voltage-controlled oscillators (VCO), it's a master of fat, warm, and expressive sounds. The Pro One is not just a synth, but a creative powerhouse with its built-in 4-pole low-pass filter and Voltage Controlled Amplifier (VCA). The synthesizer also rocks an arpeggiator and sequencer, giving musicians a wide palette to work with. Sprinkle in CV/Gate controls, and you've got the perfect companion for your vintage or modular setup.

Key Features:

Monophonic synthesizer with 2 voltage-controlled oscillators
Built-in 4-pole low-pass filter and VCA
Features an arpeggiator and sequencer
CV/Gate controls for modular setup compatibility
Rich, warm, and expressive analogue sounds
Classically designed for vintage aesthetic appeal

Product specs

Brand	Sequential
Model	Pro-One 37-Key Monophonic Synthesizer
Finish	Black
Year	1981 - 1984
Made In	United States
Categories	Analog Synths, Keyboard Synths
Analog / Digital	Analog
Key Size	Slim
Keyboard Action	Synth Action
Number of Keys	37 Keys
Polyphony	1 Voice

FAQs

Is the Sequential Circuits Pro One synthesizer polyphonic or monophonic?: The Sequential Circuits Pro One is a monophonic synthesizer, meaning it can produce one note at a time, which is ideal for basslines and lead sounds.
What kind of sound can I expect from the Sequential Circuits Pro One?: The Pro One is known for its rich, analog sound with a classic, warm tone ideal for genres like electronic, synth-pop, and new wave.
Does the Sequential Circuits Pro One have MIDI connectivity?: The original Sequential Circuits Pro One does not have MIDI connectivity as it was produced before MIDI was standardized, but it can be modified to include MIDI capability.
What is the keyboard action like on the Sequential Circuits Pro One?: The Pro One features a synth action keyboard with 37 slim keys, providing a responsive and fast-playing experience suitable for synth leads and basslines.
How does the Sequential Circuits Pro One compare to the Prophet-5?: While the Pro One is a monophonic synthesizer, the Prophet-5 is polyphonic. The Pro One shares a similar analog sound character but is more focused on single-note performance.

Videos

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Telekom Electronic Beats TV

Mathew Jonson Presents His Synthesizer Favourites: Sequential Pro One (Electronic Beats TV)

Telekom Electronic Beats TV

Sequential Circuits Pro-One Sounds

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Sequential Circuits Pro~One | Carpentry

Alex Ball

Sequential Circuits Pro One Tutorial

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Sequential Circuits Pro-One Analog Synthesizer "Lost 80s"

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SCI Pro One - review and deep dive

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Sequential Circuits Pro-One Analog Monosynth | Tutorial

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Sequential Circuits Pro-One Analog Synth, Strymon Big Sky

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How to maintain your Sequential Circuits Pro-One synth

Synthead

Pro One Keyboard Repair

Telefunkian

Reviews

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PROS

Unmatched sound quality, bridges 70s edge and 80s analog cleanliness
Powerful sequencer and modulation options
Exceptional for tight, punchy bass and snappy arpeggios
Versatile sound creation, from fat bass to experimental atmospheres
Stable chipset design, solid tuning
Offers a wide range of CV/Gate inputs and outputs
Can produce a variety of sounds including deep subs and electro arps
Simple yet inspiring sequencer and arpeggiator

CONS

High resale price may not justify the value compared to alternatives
Lack of MIDI without an upgrade
Limited production makes it rare and expensive
Prone to key triggering issues (double or triple triggering)
When a chip fails, repair or replacement can be challenging

Owner Insights

We analyzed real musician discussions from forums and Reddit to find what players love, question, and tweak about Sequential Circuits Pro One Synthesizer.

Setup and maintenance

0 0

The power supply capacitors should be replaced to prevent tantalum cap failure, which can ruin the PCB.
Source
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Bent support arms under keys can often be repositioned to fix non-working keys.
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Older Pro-One models use Pratt Reed keyboards; newer ones use rubber contacts. Both are repairable, but a full Fatar keybed replacement is often recommended for better performance.
Source

Mods and upgrades

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Fatar keybed replacements are recommended for improved playability and future resale value.
Source

User experience

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The membrane-style keybed can have broken keys and is challenging to service.
Source

Features and functionality

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The Pro-One allows for manual parameter manipulation, unlike preset-only synths like the ARP Soloist.
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Comparisons

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Behringer Pro-1 clone reportedly sounds identical to original Pro-One and includes modern features like MIDI.
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The Pro-One is noted for having snappier envelopes and more character compared to synths like the Mopho x4, which are seen as less distinctive.
Source

Value and pricing

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Original Pro-One units can sell for over $1,000 on platforms like eBay, making a $520 purchase potentially profitable after repairs.
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Use cases and applications

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Some owners use the Pro-One with CV control from a better keyboard to bypass its less reliable built-in keybed.
Source

Critic Reviews

Sequential Circuits Pro-One (EMM Mar 82)

muzines.co.uk

The Sequential Circuits Pro-One synthesizer shines as a versatile and cost-effective monophonic synth, boasting impressive design features and exceptional value. With its dual oscillator setup, intricate modulation section, and built-in sequencer and arpeggiator, it’s a robust choice for sound sculptors. The keyboard action is firm, and its filter offers a crisp, uncolored sound. However, the casework could be sturdier, and the contact system produces some physical noise. Despite these minor issues, the Pro-One remains a reliable and highly recommended instrument, particularly with its ability to interface well with other devices. Act quickly, though, as potential price increases loom.

positive

Full Review

Back to the Future: The Sequential Circuits Pro-One

musictech.com

The Sequential Circuits Pro-One Synthesizer is a nostalgic nod to 1980s synth design, offering rich analog tones and a unique modulation matrix that keeps it a favored choice for synth enthusiasts. While it boasts a comprehensive VCO section and modulation capabilities that inspire creativity, the Pro-One is marred by its subpar build quality and unreliable keyboard, which historically required frequent maintenance. The synth’s affordability at launch came at the cost of durability, with the casing and keybed drawing criticism. Nonetheless, its sound and modulation options make it a valuable addition for those seeking vintage character, provided the keyboard issues can be overlooked or bypassed.

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5.0 out of 5

Based on 7 Reviews and 24 Ratings

5 star

4 star

3 star

2 star

1 star

davekenwith

about 5 years ago

Excellent synthesizer in it's own right.... But.... Not a bit like the ARP Oddysey

Love the modulation mixer. It's not been done on that many synthesizers. It almost gives the impression on a modular - without all the hassle of cables and sockets that would eventually start to crackle and go intermittently open circuit.

Pros - nice and stable thanks to a complete chipset designed just for synthesizers designs. Cons - When one of the chips goes down, which, to be fair would be a long time ago, the whole instrument is pretty much scrap.

Unless a good engineer could redesign that specific section. I used to keep all schematics of these sort of mods. I do believe that the chipsets for these synthesizers have once again been brought back to life and the foundries have started up again. This will be.great for the second hand market once again. To own any synthesizers of this age, you either need to know a very good engineer, or you would need to have the knowledge to modify these beasties. Come to think of it, to own a studio and engineer it yourself, you (should be) just the sort of engineer to keep one of these of these on it's feet.

Roles:

Keyboardist Composer Music Producer

Genres:

Electronic Electronica Synthpop

theweekendwarrior

552

over 7 years ago

the only monosynth you need if you cant find or afford an obie two voice, ob1, kobol, syrinx

does a 303, does a deep sub, does electro arps/seqeuncing, does moogy, does arpy, does the monopoly chord memory sub octave sound, plus its great at thunder and zaps. pretty solid tuning, lots of cv/gate in and outs with trigger. fairly robust and not finicky. a solid synth, i guess thats why theyre now $1500-2000 cdn/us. in case you didn't know, millenials...we (gen-x) old timers used to pay 350-600 for these back in the ancient olden days of 1993.

Roles:

Keyboardist Composer Music Producer

Genres:

Electronic Techno Dance music

bwilson23

over 8 years ago

One of the absolute best

This is a marvellous synthesizer. Probably the best monosynth ever made after the Minimoog. It can handle pretty much anything, from smooth moogy leads to filthy bass and extreme effects. Everything you dial in sounds good, and the sequencer and arp are simple but inspiring. If you need a monosynth and can't afford a Minimoog, this is the one to get.

michael_pohl

almost 11 years ago

All in one synth for everything

Crappy keys suffering from double or triple triggering but soundwise it could be the only machine you ever need because it delivers any basic sound in outstanding quality. Fast envelopes, a strong filter which opens up to the highest highs and resonates over the entire audio spectrum, very flexible modulations, sync, fm (with a character similar to my ARP2600) and lots of other goodies. Vince Clarke was right to choose it as one of his favorite machines.

transquanta

420

over 9 years ago

My favourite synth

this is my favourite synth in my collection, it produces some wicked bass sounds and is a right staple within my collection. I wish I had the the pro 5, but I couldn't afford it last time I saw one on ebay. I have the pro 5 VST which is pretty cool, but the sound is very much different from the synthesizer in the flesh! .

jimmarchi1

41029

9 years ago over 9 years ago

ah the pro1, snappiest envelopes ever

mikefiction

1264

almost 7 years ago

Favorite Monosynth

I had it for a long time and then sold it like a chump. I regret everything. I need to get another but the price is so much higher now. Maybe the clone will be ok, maybe not. Maybe I need to get another one. I still cry every night missing my Pro One.

Roles:

Guitarist Keyboardist Audio Engineer

Genres:

Electronic Rock Electro-industrial