"This one is in excellent cosmetic condition and working 100%. It is ready to be played and needs nothing! This unit has the earlier, "j-wire" keyboard so it is serviceable if needed in the future. Please mail with any questions. Shipping to most countries! The shipping price listed is just an estimate. If it is less, you will be refunded. NOT SOLD AS-IS!
***This is marked as a USA sale, but I will ship to most countries.***
Cosmetically- Nothing is ever mint in my opinion and this one is no exception. There are some imperfections here and there, but overall I think it looks excellent. All knobs have been replaced, it has new wood sides (walnut), and a new "Sequential Circuits" sticker.
Internally- Apart from any repairs, it's been completely disassembled and cleaned, all potentiometers and switches have been cleaned, it has two new octave switches, all electrolytic & tantalum capacitors replaced (including the power supply), the keyboard rebuilt with new bushings, the j-wires & buss-bar have been hand polished, and it has been fully calibrated. *This may be updated!"
A new 10-voice analog-style synth for iPhone and iPad. Inspired by a legendary Poly Synthesizer.
PRO-A5 captures the warm and organic sound of the most iconic analog poly synth ever made. From lush brass, silky pads, screaming resonance and punchy basses to soaring leads, this is the sound that defined MUSIC ICONS from the ’80s to today. Be inspired by the same synth sounds used on thousands of records you already love.
JAM PACKED
Features 400+ Presets by Moby Pixel, Analog Matthew, Doug Woods (The Sound Test Room), Bri Kup, DMT Cymatics, Red Sky Lullaby, Joe Zeno, and more!
FEATURES:
New Sound Engine with advanced DSP
Professionally Modeled Filter, with Self Oscillation
2 Filters: Classic “REV 3” with Stepping & Modern Smooth
10 voices! Each note can have 5 unison voices. Almost a P-50?!
500+ Exclusive Handmade Presets!
Vintage Poly Mod with per-voice modulation
Raw, gritty Oscillator Sync
Magic “Tune Rez” button to instantly tune the self-oscillation!
Bonus Filter panel with Filter Slopes, Env Inversions, and other goodies
Per-Voice Analog Panning
Single Note Polyphony for mono & poly
Accurate PWM engine, with the Hardware’s unique Poly-Mod behavior
2x oversampling for more analog-style lows and highs
NEW Reverb, cascading and beautiful
FX: NEW Rage Limiter, Analog Tape Delay, Chorus, Crush, and more.
3 LFOs, over 60+ possible destinations, almost everything can be modulated! LFOs can even modify other LFOs
Aftertouch! Control any of the Parameters
Dual Assignable Touch Pads, manipulate FX in real time!
"Up for sale is my beloved pro-one. The keyboard has been replaced with an amazing feeling keybed from Techsmechs. it was recapped and gone over by AZ TV Worx around a year ago. It shows some signs of wear including some wear on side panels, a missing knob, and a slightly worn power cable. Everything is fully functional and sounds incredible . I have included links to me performing with this exact synth."
Click the auction link on top when you get there for additional listings.
"Extremely rare outside Japan - apparently Moridaira / Denki Sangyo, the firm SCI employed to make the Six-Trak, decided to make a few changes to that design and re-market it as the Pro-8 in Japan. Five octaves instead of four, eight voices instead of six, and split instead of multi-timbral. SCI then eventually made a couple more changes, and introduced it as the Split-8 in the rest of the world.
This, like all Pro-8s, started out as 100V Japanese power, but has been converted to 240V.
Lots of little points of interest: for instance, this one has a Denki maker label but also a Sequential Circuits one. They both call it Model 608, and SCI have a serial number:02033. 608 presumably because the design was changed from six to eight voices?
It's not a Prophet-5 for sure.... but if you like the Six-Trak sound you'll like this a lot. And it's rare as anything :) Plus it's probably the only synth in the world to have a scribble-strip matrix for entering your program sound names. The matrix looks unused.
"The-One by Nerve is not a replica, but a musical study inspired by the Sequential Circuits Pro-One. Available as VST3 and AU for macOS and Windows.
https://nerve-audio.com
In this video, we explore the sonic range of this synthesizer using the MP Controller.
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MP MIDI Controller | https://www.mpmidi.com
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Click the auction link on top when you get there for additional listings.
"Great and powerfull analog synth from 70's This one is in excellent cosmetic conditions (I am the 2nd owner and always kept in free-smoked studio as the 1st owner too) the Pro-One can generate many of the same sounds as the Prophet-5 and Prophet-10, capable of supremely punchy bass lines and distinctly ripping leads, fueled by two VCOs, referred to as Oscillator A and Oscillator B. he Pro-One has extensive modulation provision with three modulation sources available, featuring Filter Envelope Generator, Oscillator B, and a separate LFO. Each can be mixed and routed for either Direct or Wheel-controlled modulation. On the back of the unit, there are Audio, Filter CV, Gate/CLK, and CV inputs. Other features include a 40-note sequencer, an arpeggiator, Pitch and Mod wheels, Repeat and Drone switch, Single and Multiple-triggering keyboard modes, and the unique Automatic Glide, enabling one-handed complex, 'tuned' pitch bending sounds."
"What makes 'Don’t Go' by Yazoo one of the most iconic synthpop tracks of the 1980s?
In this video, I explore how Vince Clarke shaped the sound of early electronic music through his work with Yazoo, and how his minimalist but powerful approach to synthesizers helped define an entire genre. After leaving Depeche Mode, Clarke refined his production style — focusing on strong melodies, tight sequencing, and bold synth sounds — and “Don’t Go” is one of the best examples of that evolution.
Before diving into the recreation, I share a bit of context around Yazoo and why this track became so influential across synthpop and electronic music.
Then I take you into the studio.
Step by step, I recreate the track using a combination of vintage hardware and modern tools inside Logic Pro. For this version I used:
• Sequential Circuits Pro-One – basslines and lead elements
• Sequential Drumtraks – drum programming
• Logic Pro VST instruments – additional textures and supporting sounds
I walk through the recording process, sequencing, arrangement, and showing how each layer comes together to recreate the energy of the original track.
It is interesting to understand how Vince Clarke’s production approach continues to influence modern electronic music, from synthpop to contemporary electronic genres."
"The Sequential Circuits Pro-One is one of the most legendary mono synthesizers of the 1980s—and responsible for some of the most iconic sounds of the synth-pop, new wave, and industrial era.
In this video, you'll hear famous Sequential Pro-One sounds and riffs used in real hits from the 80s.
From powerful basslines to screaming leads to sequenced arpeggios, the Pro-One stands for raw analog character and a sound that has shaped entire decades. Yazoo used the Sequential Pro-One in the album Upstais At Eric`s.
The Pro-One Sounds:
0:07 Yazoo Tuesday
0:26 Yazoo Don`t Go
0:40 Yazoo Bring Your Love Down
0:54 Yazoo Only You
1:11 Yazoo Situation
1:25 Yazoo Goodbye 70s
1:38 Yazoo Two Pieces
1:52 Berlin Metro
2:08 Berlin Masquerade
2:25 Peter Schilling Major Tom
2:48 Secret Service Flash In The Night
3:18 Beagle Music Like Ice In The Sunshine
3:30 Eurythmics Here Comes The Rain Again"
"MaskinTrommer is a drum sample library for Decent Sampler, featuring electronic drum sounds created from analog synthesizers. Each drum type contains multiple samples per sound to eliminate the typical 'machine gun' effect associated with digital sample based drum machines.
The drum sounds were created using: Korg MS-20 Roland SH-09 Doepfer Dark Energy Sequential Circuits Pro-One The result is a versatile collection of synthetic kicks, snares, hi-hats, cymbals, and toms with a broad tonal range, from tight and percussive to big and sustaining.
User Interface: The interface is divided into two main areas Left section: Individual drum controls and sample mixer Right section: Global settings and effects The keyboard at the bottom is color-coded to match each drum section, making it easy to identify the mapping.
Drum Settings The top row of knobs in each drum section controls the primary sound-shaping parameters.
Pitch (Kick & Snare): Adjusts the tuning of the drum. Turning clockwise raises the pitch. Turning counterclockwise lowers the pitch. Affects both sample types for the kick and the "body" samples for the snare.
Sustain (Snare, Hi-Hat, Cymbal, Tom): Controls which sustain-length samples are triggered. For snare and tom, it only affects the "head" samples. Lower values select shorter, tighter sounds. Higher values select longer sustaining samples. Dyn (Dynamic) mode: Higher MIDI velocity → longer sustaining samples Lower MIDI velocity → shorter sustaining samples
This allows expressive control directly from performance dynamics.
Drum Mixer The second and third rows of knobs in each drum section form the sample mixer. Each knob controls the volume of a specific sample type for that drum. The knob design visually represents which synthesizer the samples originate from.
Sample Type Blending: You can blend multiple synthesizer sources for a single drum. Each active source contributes its own round robin variations. Combining sources dramatically increases variation and complexity.
Display Indicators: Some mixer knobs include a small display. The display shows how the samples assigned to that knob are influenced by either pitch (kick & snare) or sustain (snare, hi-hat, cymbal & tom). This provides quick visual feedback when shaping the sound.
Global Settings Located in the rightmost section.
Sensitivity: Controls how strongly MIDI velocity affects sample volume. Lower values → More consistent volume regardless of velocity Higher values → Greater dynamic range This allows you to tailor the instrument to your playing style or sequencing needs.
Global Effects Impact: Controls the level of the transient (initial attack) relative to the sustain portion. Higher values → Louder attack, quieter sustain Lower values → More even balance between attack and body This is useful for tightening drums or making them cut through a mix.
Saturation: A volume-compensated overdrive/distortion effect. Adds harmonic content and edge. Maintains perceived loudness while increasing intensity. Suitable for subtle coloration or more aggressive processing.
Keyboard Layout The on-screen keyboard is color-coded to match the drum sections: Kick (pink): C1 Snare (blue): D1 Closed hi-hat (green): E1 Open hi-hat (green): F1 Cymbal (yellow): G1 Tom (red): A1 to G2 This makes it easy to identify which keys trigger which drums, especially during performance.
Equipment used: Doepfer Dark Energy Korg MS-20 Roland SH-09 Sequential Circuits Pro-One
Technical specification: Sample rate: 48 kHz Bit depth: 24 bit Channels: 1 (mono) Number of samples: 342 File size: 80.4 MB
"Welcome to RetroSound Studio Tour: Analog Monophonic Synthesizers & Duophonic — a deep dive into legendary mono synths from the 1970s and 1980s, including rare East-Bloc classics.
In this new episode, I showcase iconic instruments such as the Minimoog, ARP Odyssey, Roland SH-101, Maxi-Korg, Sequential Circuits Pro-One, alongside Soviet and East German synthesizers like the Polivoks, Alisa 1377 and Vermona mono synths.
These analog monophonic synthesizers defined the sound of electronic music — from the fat Moog and cutting ARP to aggressive Polivoks and raw Eastern European character.
This video explores the sound and architecture of true analog mono synths built around VCO, VCF, and VCA signal paths, highlighting their distinctive basslines, lead sounds, and modulation capabilities. From the Moog basslines to the aggressive Polivoks filter sound and the unique character of East German Vermona synthesizers, each instrument demonstrates why 1970s and 1980s monophonic synthesizers remain highly sought after by collectors, producers, and electronic music enthusiasts."
The Monophonic Analog Synths:
0:07 Maxi-Korg 800DV
3:17 Sequential Pro-One
6:30 ARP Odyssey Mk. III
8:39 Roland SH-101
11:56 Moog Prodigy
15:24 Moog The Source
17:34 Moog Micromoog
18:16 Moog Minimoog
20:56 Moog Taurus
22:21 Formanta Polivoks
24:44 Rodina Alisa 1377
26:48 Vermona Synthesizer
"The Sequential Circuits Pro-One is a legendary monophonic analog synth prized for its fat bass, searing leads, and incredibly flexible modulation capabilities. Compact yet powerful, it delivers the iconic Prophet-series sound in a hands-on design that’s become a must-have for serious synth players and collectors.
This Pro One has the J-wire (Pratt Read) keybed and is in good condition. This Pro One was serviced by Synthchaser in February 2026. Work done included:
· Recapped all original tantalum capacitors & power supply capacitors
· Keybed refurbished - new bushings, bus bars & j-wires cleaned
· Cleaned pots & switches
· New power cord & quiet power transformer
· Tuned & calibrated"
"Vintage synths, meet contemporary synths. The Leploop clocks everything, with clock division by the Mofenseef Pocket Clock-it. There's a resonant arpeggio on the SH-101, but the real star here is the Sequential Circuits Pro-One and its gnarly filter (also getting pitch CV from the Leploop). It's gets pretty noisy, but I like it noisy.
Delay is added by the Korg NTS-1 MK II, mixed on the Yamaha KM802.
Recorded live on the Zoom L6, audio normalized in Audacity.
"Original SCI Pro-One with MTG Turbo MIDI kit installed!
Cosmetically, it's seen better days, but sonically - it works. Has been stored for two years and some key contacts needed playing after that time. It's time for a new home where it's appreciated!
The instrument was serviced in 2023 by the legendary Greg Montalbano of Analog Synth Service in Oakland.
Cleaned, tuned & scaled.
Assessment: MTG MIDI unit works, but the CV option was incorrectly soldered, and the DAC for the optional CVs doesn't work.
Upgraded fixed power cord to removable IEC power socket"
"This one is in excellent cosmetic condition and working 100%. It is ready to be played and needs nothing! This unit has the earlier, "j-wire" keyboard so it is serviceable if needed in the future. Please mail with any questions. Shipping to most countries! The shipping price listed is just an estimate. If it is less, you will be refunded. NOT SOLD AS-IS!
