SIEL OR400 Analog Synthesizer Arp Orchestra Sequential Prelude Circuits

( Brand: Siel ), ( Type: Keyboard Synthesizer ), ( Analog/digital: Analog ), ( Manufacturer Part Number: OR400 )

Review SIEL Vintage Analog Synthesizer Arp Orchestra Sequential Circuits Prelude

The Siel OR400 Analog Synthesizer, also known as the ARP Orchestra or Sequential Circuits Prelude, is a legendary analog polyphonic synthesizer that was initially produced between 1979 and 1981 by the Sequential Circuits company, founded by Dr. Donald Buchla and Dave Smith. This synthesizer is a highly sought-after instrument for its lush, rich, and complex sounds that have graced numerous records in various music genres, especially instrumental and electronic music.

The OR400 is a polyphonic synthesizer, meaning it can generate multiple notes at the same time. It features six voices, each with its oscillator, filter, amplifier, and envelope generator. Each voice offers a choice of two oscillators - oscillator A and B - that can be set to sine, square, sawtooth, or pulse waveforms. These oscillators can be sync'ed or can be frequency modulated ( FM), providing a wide spectrum of sonic possibilities. The OR400 also comes with a sub-octave generator that can shift the fundamental pitch of each voice an octave or a fifth below the main pitch, creating a thick and powerful bass tone.

Filtering in the OR400 is provided by a 24 dB/octave resonant low-pass filter, which is known for producing warm and interesting distortion when pushing it beyond its self-oscillation point. Each voice has its dedicated filter and envelope, allowing the use of up to six independent filters and envelopes.

The OR400's envelope generators offer four segments: attack, decay, sustain, and release. The attack time can range from 0 to 2 seconds, while the decay and release times can range from 0 to 3 seconds. Both ADSR (Attack, Decay, Sustain, and Release) and ADSR with delay are available envelope Generator modes. Just like any other analog synthesizer, these envelopes control the amplitude of the output sound.

Figure 1: Siel OR400 Synthesizer Vintage keyboards.com

In terms of modulation, the OR400 provides a dedicated LFO that offers two waveforms - sine and square - and can modulate any oscillator frequency as well as the filter cutoff. This LFO has a range from 0 to 10 Hz and can be synchronized to MIDI clock signals, making it suitable for creating rhythmic and melodic modulations.

The sequencing capabilities of the OR400 expose its 'ARP ORCHESTRA' nickname. With its built-in 32-note polyphonic sequencer, you can program complex, beautiful, and intricate arpeggios. Every note in the sequence can be assigned a different root note, creating unique and unexpected chord progressions to develop your melodies with freedom and creativity.

Additional features of the OR400 include its connection options like MIDI in and out jacks, CV inputs for each control voltage input for external control of pitch, filter cutoff, and envelope generators. It also has two audio output jacks for the main audio output and a headphone output jack.

With a master clock input capable of receiving an external clock signal, the OR400 can be synchronized and be the centerpiece of a modular setup or create polyphonic sequences that have a consistent timing with other sequencers.

Lastly, the OR400 sports an attractive yet simple control panel, with an easy-to-read and understand layout that simplifies the creation of intricate sounds and mathematically complex music. The keys and knobs are well-placed and ergonomically friendly for playing and tweaking settings on the go, providing a fantastic user experience.

In summary, the Siel OR400 Analog Synthesizer, AKA ARP ORCHESTRA or SEQUENTIAL CIRCUITS PRELUDE, is a coveted, versatile, and powerful six-voice polyphonic synthesizer that provides a rich palette of sounds and features for creating complex melodies and intriguing soundscapes. Its unique capabilities and elegant design have endeared it to musicians and collectors alike, as it continues to inspire and pave the way for modern electronic musical instruments.

Pros and Cons of buying a Siel SO-400, ARP Oracle, or Sequential Circuits Prelude Analog Synthesizers

- Polyphonic synthesizer capable of generating rich and complex sounds with its 32 voices and 8-part multitimbral capabilities.

- Versatile sound engine featuring two voltage-controlled oscillators (VCO), two voltage-controlled filters (VCF), two voltage-controlled amplifiers (VCA), and an envelope generator (ENV).

- Includes a built-in arpeggiator and various modulation sources, such as an LFO and an envelope follower (ENV Follower).

- MIDI and CV/Gate connectivity, allowing users to incorporate it into modern setups and integrate it with a wider range of equipment.

- Complex user interface that may take some time to fully understand and master.

- Limited patch memory, with only 50 factory presets and five user-definable memories.

- Quite large and heavy compared to other synthesizers in its class, making it less portable.

- Approaching the higher end of the mid-range synthesizer price spectrum.

- Iconic and highly sought-after vintage analog synthesizer, featuring four independent voice structures capable of generating thick and lush sounds.

- Each voice has its unique character, with two oscillators per voice, three filter types, VCA, and two envelope generators.

- Extensive modulation capabilities, including five LFOs and a 16-step sequencer.

- MIDI compatibility makes it a versatile addition to modern studios.

- Highly expensive considering its age and potential need for repair and maintenance.

- Limited memory and patching capabilities, which might make it less suitable for studio productivity.

- Wonky control interface when compared to modern synthesizer designs, which could potentially hinder workflow.

- Less portable than some synthesizers due to its size and weight.

- Analog monophonic synthesizer, providing rich and resonant sounds.

- Straightforward interface that is refreshingly simple and easy to understand.

- Portable and affordable, making it an excellent choice for beginners and those who require a small synth setup.

- Includes a variety of features like transposition, glide, and 1V/octave CV/Gate inputs.

- Monophonic design limits its versatility for playing chords, complex harmonies or multiple parts simultaneously.

- Limited number of modulation sources, making it less suitable for advanced sound design or complex sequences.

- It may not be as powerful as other synthesizers, but for its entry-level price point, it offers excellent value.

When deciding between the Siel SO-400, ARP Oracle, and Sequential Circuits Prelude analog synthesizers, potential buyers should consider their required features, preferences, workflow, and budget. The Siel SO-400 is best suited for power users seeking a professional, polyphonic synth with modern connectivity options. The ARP Oracle is the ideal choice for quintessential synthesizer enthusiasts willing to invest significantly for an iconic, vintage experience and providing rich, complex sounds. Lastly, the Sequential Circuits Prelude is the perfect stepping stone for beginners or those on a tight budget, who are looking for an accessible and straightforward synthesizer.

part # or400 prices

• $11.60-$399.00

specifications synthesasha:

• brand: Siel
• type: Keyboard Synthesizer
• analog/digital: Analog
• manufacturer part number: OR400

shipping synthesasha:

• type: Fixed
• class: Economy
• service: UPS Ground Saver
• carrier: UPS
• transit: 11-14 Days
• cost: $70.00

payments synthesasha:

• other
• credit card: Discover
• wallet: Paypal

returns synthesasha:

• policy: No Returns

general synthesasha:

• Musical Instruments Gear > Pro Audio Equipment > Synthesizers
• condition: Used

offer synthesasha:

• quantity: 1
• started: November 1, 2024
• options: Ship-to-home
• sold: 0
• availability: In Stock
• best offers: True

seller synthesasha:

• # reviews: 65
• rating: 95.7%

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