Sequential Fourm Compact Polyphonic Analog Synthesizer For Sale

The Sequential Fourm compact polyphonic analog synthesizer delivers the soul of classic analog synthesis in a compact, hands-on unit. Built around the Prophet-5 voice structure, this synth features dual oscillators with simultaneous waveform selection and a 4-pole low-pass filter. The addition of bass compensation boosts low-end response, giving every patch more punch. Polyphonic aftertouch on the 37-note slim-key keyboard lets you bend notes or swell chords, unlocking expressive techniques not possible on most polysynths. With intuitive top-panel modulation, the unit is designed for musicians who want immediate access to sound-shaping tools—without menu-diving

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Sequential Fourm Compact Polyphonic Analog Synthesizer item# 1500000465983New

The Sequential Fourm compact polyphonic analog synthesizer delivers the soul of classic analog synthesis in a compact, hands-on unit. Built around the Prophet-5 voice structure, this synth features dual oscillators with simultaneous waveform selection and a 4-pole low-pass filter. The addition of bass compensation boosts low-end response, giving every patch more punch. Polyphonic aftertouch on the 37-note slim-key keyboard lets you bend notes or swell chords, unlocking expressive techniques not possible on most polysynths. With intuitive top-panel modulation, the unit is designed for musicians who want immediate access to sound-shaping tools—without menu-diving. Studio producers and synth enthusiasts will find this synthesizer ready for live play, sound design and hands-on experimentation straight out of the box.

Prophet-5 Voice Structure Delivers Iconic Analog Tone

The core of this synthesizer uses true analog oscillators modeled after the Prophet-5, producing a warm, organic sound. Dual oscillators offer simultaneous wave selection, while oscillator B also supports low-frequency operation for added modulation options. The 4-pole resonant filter, now enhanced with bass compensation, shapes each tone with clarity and depth. This architecture provides a punchy, dynamic response that stands out in any mix.

Polyphonic Aftertouch and Slim Keys Enable Expressive Performance

Polyphonic aftertouch across the 37 slim keys creates new opportunities for real-time musical expression. Players can bend notes, add swells or articulate each voice independently—actions usually reserved for high-end or vintage gear. This unlocks creative phrasing, making each performance more personal and detailed.

Hands-on Modulation Matrix Simplifies Sound Design

The Pro-One inspired modulation matrix sits on the top panel, using buttons and color-coded indicators for fast routing. Players select sources and destinations without scrolling through screens, visualizing complex paths instantly. This layout keeps the creative flow going, letting users experiment and build sounds quickly—crucial in both stage and studio settings.

All-Steel Chassis Provides Lasting Durability

This unit features a solid, all-steel chassis for maximum strength and longevity. High-quality knobs and switches feel precise under the fingers, while the anti-theft slot adds security for gigging musicians. Reliable construction ensures the synthesizer stands up to regular transport and long sessions, year after year.

Fourm Synthesizer Experience Rewards Creative Players

Performers and producers who value hands-on control and a classic analog signal path will connect with this synthesizer\'s direct interface and flexible expressiveness. The combination of polyphonic aftertouch, fast modulation routing and robust build supports musicians who want to push sound design and live performance further. Immediate access to deep features inspires new techniques and helps transform creative ideas into finished tracks.

Features:

Warm, 100% analog signal path delivers rich and organic tones
Dual oscillators with simultaneous waveforms create layered and complex sounds
Prophet-style 4-pole resonant filter adds punch with bass compensation
Polyphonic aftertouch unlocks expressive techniques like bends and swells
Pro-One-inspired modulation matrix allows intuitive routing and sound design
Sequencer with glide per step creates fluid, evolving patterns
response drive circuit adds aggressive edge for bold, dynamic tones
USB and MIDI ports ensure seamless integration with modern setups

Specifications:

Synthesis
Voices: 4 genuine analog voices (based on Prophet-5 architecture)
Oscillators: Dual oscillators per voice with simultaneous waveform selection (Oscillator B supports low-frequency modes)
Filter: Classic Prophet-lineage 4-pole resonant low-pass filter with bass compensation
Envelopes: 2 x ADSR envelopes (authentic Prophet-5 response curves)
response: Aggressive drive circuit
Oscillator Sync: Classic Prophet-style sync
LFO: Multi-waveform (simultaneously selectable)
Keyboard
Keyboard: 37-note slim-key with polyphonic aftertouch
Modulation & Controls
Modulation: Pro-One style top-panel modulation matrix (no menus)
Arpeggiator: Built-in arpeggiator with sequencer mode, glide per step
Presets
Presets: 128 world-class factory presets
Connectivity
Audio Output: 1 x 1/4\" Mono (Main)
Headphone Output: 1 x 1/4\" TRS (Mono)
MIDI: In, Out, Thru (5-pin DIN)
USB: offerirectional MIDI communication
Pedal Input: Footswitch/Expression pedal input
Power
Power Supply: 12V DC, 1.2A (included), center-positive
Power Consumption: 14W maximum
AC Input: 100–240V, 50/60Hz (universal)
Power Switch: Separate on/off switch
Construction
Chassis: Pro-quality, all-steel chassis
Security: Anti-theft slot
Included Accessories
12V DC power supply
Dimensions & Weight
Dimensions (WxHxD): 22.13\" (56.20 cm) x 2.76\" (7.00 cm) x 9.88\" (25.10 cm)
Weight: 8.75 lb. (3.97 kg)

Shipping
Orders are generally shipped the following business day after payment is received. For example, if your order is placed AND paid for at 1 p.m. Eastern Time on Friday, Musicians Friend will ship it on Monday. We are only shipping orders via standard ground shipping at this time (3-7 business days for delivery once the item leaves our warehouse)Payment
We use Managed Payments and accept the following forms of payment credit, debit, and gift cards, Apple Pay, Google Pay, PayPal, and PayPal Credit. Sales Tax
We are required to collect sales tax on all orders, except those shipped to the following states: Alaska, Delaware, Montana, New Hampshire and Oregon.Store Policies
If you’re not satisfied, neither are we. If for any reason you’re not completely satisfied with your purchase of a new item, simply return it in its original condition within 45 days of purchase (see exceptions below) and we’ll give you a full refund. It’s that simple. Returned items must be in original, brand-new condition, showing no signs of wear or use such as belt-buckle or pick scratches, scuffs, dings or scrapes on the instrument or collateral materials. Items must also include all original packaging, manuals, warrantees and accessories or your return may be subject to a return handling charge.Your refund will be promptly processed upon successful evaluation of your returned item from our trained category professionals in 2-3 business days. Refunds are made for product value only, excluding shipping and handling charges. If you received Free Shipping on your order, the value of the uncharged shipping cost will be deducted from your refund.Limitations and Exceptions
Returns of the following products must be made within 10 days of shipment - Stringed instruments priced at $1999.00 or more. The following products cannot be returned – Clearance items, Apple products, items identified as non-returnable, discontinued items, electronic software downloads, demo gear, vintage instruments, strings, reeds, computers, tubes, earbuds, earplugs, recorders, tin whistles, flutophones, \"world\" wind instruments, harmonicas, raw-frame speakers, drumheads, drumsticks, turntable cartridges, fog fluid, clothing/footwear, body jewelry, sheet music, cleaners, polishes and polishing cloths, software/soundware, books, CDs, DVD\'s, vinyl records, and videos.The following fees apply to Band & Orchestra returns - All returned woodwind and brass instruments incur a $10.00 sanitization fee. Returned bows are assessed a $4.00 restocking fee. Returned mouthpieces over $300 incur an $8.00 sanitization fee; the fee for mouthpieces under $300 is $4.00.Should you decide to return your shipment, please follow the return steps printed on the back of your invoice and pack your return carefully to prevent damage in shipment. All returns must:1. Include a Return Authorization Number; (Please contact us via messages for an RA number)2. Be in the original packaging complete with all collateral materials such as cases, straps, cables, care kits, certificates of authenticity, warranty cards, manuals, and any other materials that originally shipped with the instrument; 3. Be in brand-new condition, showing no signs of wear or use such as belt-buckle or pick scratches, scuffs, dings, or scrapes on the instrument or collateral materials.