Seventh Circle Enterprises

What Seventh Circle Enterprises does

Seventh Circle Enterprises, doing business as Seventh Circle Audio (SCA), is a privately held analog audio hardware company headquartered in Rochester, MN. The firm designs, manufactures, and sells professional microphone preamplifiers and adjacent recording signal-chain modules—including VCA compressors, high-pass/low-pass filters, and active DI boxes—modeled after classic console circuitry from API, Neve, Jensen, John Hardy, Harrison, and SSL. Its product architecture is modular: preamp modules plug into either a proprietary CH02 8-channel chassis with integrated power supply or a PC01 single-module case, with a parallel 500 Series line distributed into third-party racks. Each module is offered either as an unassembled DIY kit with freely downloadable schematics and documentation, or as a fully assembled plug-and-play unit, allowing the firm to serve both hobbyist builders and time-constrained professional buyers at price points ranging from $4 (colored knobs) to $929 (CH02 starter pack with J99 preamp).

Name

Seventh Circle Enterprises

Legal name

Seventh Circle Audio

Website

https://seventhcircleaudio.com

Company type

Private

Founded year

2005

Operating status

Operating

Headcount range

1–10 employees

Short description

Seventh Circle Enterprises (dba Seventh Circle Audio) designs and sells modular analog microphone preamplifiers, compressors, filters, and DI boxes, offered as DIY kits or fully assembled units for DIY enthusiasts, home studios, and professional recording customers worldwide.

Ownership category

akta.pro rank

Product category

Professional Audio Recording Equipment

NAICS

Audio and Video Equipment Manufacturing (33431)

SIC

Musical Instruments (3931)

akta.pro primary industry

Pro Audio Equipment (Mics, Interfaces, Mixers, Studio Monitors) (MPAIAJAB)

Keywords

• Microphone preamplifiers
• Professional audio recording equipment
• 500 series modules
• DIY audio kits
• Studio recording gear

Headquarters

HQ city

Oakland

HQ country

United States

HQ region

North America

Offices2 records

Markets served

GTM type

B2C

Offering type

Hardware or Manufacturing

Cost components

Supply Chain, Operations, Personnel, Technology or R&D, Marketing or Sales, Infrastructure

Revenue model

1. DIY Microphone Preamp Kits: One-time sale of unassembled microphone preamp kit modules including N72, A12B, J99, C84, and S90 models along with supporting components like transformers, op-amps, and subpanels.
2. Fully Assembled Microphone Preamps: One-time sale of professionally assembled preamp modules ready for immediate use in recording studios.
3. Chassis and Power Supply Units: Sale of CH02 (8-channel), PC01 (single channel), and accessory components including faceplates, divider panels, and replacement parts.
4. Calibration and Factory Test Service: $50 service for calibrating and testing customer-assembled preamp modules to ensure proper operation.

Pricing tiers

Go-to-market motion1 record

Distribution channels1 record

Marketing channels5 records

Core offering

Seventh Circle Enterprises (dba Seventh Circle Audio) designs, manufactures, and sells analog professional audio recording equipment—principally microphone preamplifiers—available as both DIY kits and fully assembled units. Its product family spans a proprietary modular Classic Series chassis (CH02 8-channel and PC01 single-module), an industry-standard 500 Series line, plus companion compressors, DI boxes, and filters, reproducing classic Neve, API, Jensen, and SSL console circuit designs at accessible price points. The company also offers factory calibration and repair services for its modules.

Product overview

Seventh Circle Audio offers a modular preamplifier ecosystem featuring both Classic Series modules for their proprietary CH02/PC01 chassis and 500 Series modules for compatible 500 Series racks. The Classic Series includes five preamp modules (N72 Neve-style, J99 Jensen/John Hardy-style, A12B API-style, C84 ultra-clean, S90 SSL-style, and T15 budget), plus B16 VCA compressor, D11 dual DI box, and H32 filter module—all designed to work with the CH02 8-channel chassis or PC01 single-module case. The 500 Series line mirrors most Classic modules (N72, J99, A12, C84, S90, T15, B16) in a standardized format. Products are available as DIY kits for builders with soldering skills or fully assembled units. The company specializes in recreating iconic vintage audio circuits using quality components including Carnhill, Cinemag, Jensen, and Lundahl transformers.

Differentiator

Problem solved

Functional benefit

Brands

• SCA: Acronym used throughout the website and products for Seventh Circle Audio

Products and services

• SCA N72 Microphone Preamp Module (Classic Series) Neve-style transformer-coupled microphone preamp delivering the classic warmth and color of Neve console modules; up to 70 dB gain via Carnhill input and output transformers, based on BA183 circuitry used in Neve 1073/1272 consoles. Sold as both DIY kit and fully assembled unit for the CH02 8-channel or PC01 single-module chassis, priced at $449.
• SCA N72-500 Series Microphone Preamp Module Neve-style microphone preamp in the industry-standard 500 Series format, delivering up to 70 dB of gain with Carnhill input and output transformers and an input impedance select switch, sharing the same BA183-based circuit as the Classic Series N72. Priced at $499.
• SCA J99 Microphone Preamp Module (Classic Series) John Hardy / Jensen-style microphone preamp based on the classic Jensen Twin Servo design; high-gain, low-noise, low-distortion performance via a Lundahl input transformer and Cinemag output transformer with per-op-amp DC servos and no capacitors in the signal path. Sold for the CH02/PC01 chassis, priced at $449.
• SCA J99-500 Series Microphone Preamp Module Jensen Twin Servo-style microphone preamp in 500 Series format with a Lundahl 1538XL input transformer and CineMag CMOB-2H output transformer; EIN approaching -130 dB, available with or without SC90 opamps. Priced at $499.
• SCA A12B Microphone Preamp Module (Classic Series) API-style single-stage preamp based on classic American designs of the early 1970s with aggressive midrange and pronounced transformer coloration, using a CineMag CMMI-8-PCA input transformer, CMOQ-2S output transformer, and a built-in high-performance discrete SC25 op-amp. Sold as DIY kit or fully assembled for CH02/PC01, priced at $339.
• SCA A12-500 Series Microphone Preamp Module API-style microphone preamp in 500 Series format featuring aggressive midrange, CineMag CMMI-8-PCA input and CMOQ-2S output transformers, built-in SC25 discrete op-amp, and stepped gain control delivering 70 dB of gain. Priced at $389.
• SCA C84 Microphone Preamp Module (Classic Series) Ultra-clean transformerless microphone preamp based on the 1984 "Double Balanced" circuit with a DC-coupled signal path, dual DC servo circuits, and a discrete Z-Buffer output capable of driving 600 ohm loads to +32 dBu; tuned for acoustic instruments and accurate source capture. Priced at $279.
• SCA C84-500 Series Microphone Preamp Module Ultra-clean transformerless microphone preamp in 500 Series format, using the same "Double Balanced" circuit with two DC servo circuits and a discrete Z-Buffer output capable of driving 600 ohm loads to +32 dBu. Priced at $329.
• SCA S90 Series Microphone Preamp Module (Classic Series) SSL 9000-style transformerless microphone preamp delivering unmistakable SSL console character, with switchable OFF-220 Hz high-pass filter via 12-position Grayhill switch, stepped gain control in 5 dB steps from 15 dB to 70 dB, and polypropylene coupling capacitors instead of an input transformer. Priced at $279.
• SCA S90-500 Series Microphone Preamp Module SSL 9000-style transformerless microphone preamp in 500 Series format, delivering up to 70 dB of gain with a switchable OFF-220 Hz high-pass filter on a 12-position Grayhill switch. Priced at $329.
• SCA T15 Microphone Preamplifier Module (Classic Series, assembled only) Transformerless budget microphone preamp built around THAT Corporation 1512 and 1646 ICs, offering up to 70 dB of gain via a 12-position Grayhill stepped gain switch with 5 dB steps, dual DC servos, and phase reverse. Sold only fully assembled; priced at $229.
• SCA T15-500 Series Microphone Preamplifier Module Transformerless budget microphone preamp in 500 Series format using THAT Corporation 1512 and 1646 ICs, with up to 70 dB gain and a 12-position Grayhill stepped gain switch; sold fully assembled only. Priced at $279.
• SCA B16 Compressor Module (Classic Series) VCA compressor for the Classic Series built around the THAT Corporation 4305 dynamics processor IC, with relay-switched 6 dB input pad, switchable hard/soft knee, mix control for parallel compression, wide control range (threshold -40 dBu to +20 dBu, ratio 1:1 to infinite), and program-dependent attack and release. Priced at $299.
• SCA B16-500 Series Compressor Module 500 Series format VCA compressor built around the THAT Corporation 4305 dynamics processor IC, with relay-switched 6 dB input pad accepting up to +30 dBu signals, switchable hard/soft knee, mix control, and program-dependent attack and release. Optional output transformer available. Priced at $349.
• SCA D11 DI Module Two-channel active DI accepting high-impedance unbalanced instrument-level input and producing low-impedance balanced mic-level output, with switchable impedance (1M/100K/10K ohms), linkable inputs, wide bandwidth, high-current class A design, and an optional Jensen or Cinemag transformer for fully floating isolated output. Sold fully assembled only; priced at $199.
• SCA H32 High-pass/Low-pass Filter Module Harrison-Ford-style transformerless 12 dB/octave filter delivering classic console character, with switchable high-pass (20-220 Hz) and low-pass (3 kHz-22 kHz) settings on 12-position Grayhill switches, plus bypass and LP-off switches. Available as DIY kit or fully assembled; priced at $229.
• CH02 8-Channel Chassis with Power Supply 2RU road-worthy chassis accommodating up to 8 Seventh Circle preamp modules, with heavy-gauge cold-rolled steel construction, 3/16" black anodized aluminum front panels, heavy steel dividers for magnetic isolation, illuminated +30V/-30V/+48V health indicator, and a low-noise PS04 power supply accepting 85-250 VAC at 50/60 Hz. Priced at $349.
• PC01 Single Module Case with Power Supply Compact 1/4U chassis for a single SCA module, including a 115 VAC wall-mount transformer, rugged 18 gauge nickel-plated steel chassis, built-in DI with bootstrapped 2 mega-ohm input impedance, relay-switched 20 dB input pad, and tabletop or rack-mount configuration—aimed at podcasters and singer/songwriters. Priced at $229.
• CH02 Plug and Play Starter Packs Pre-configured bundle pairing the CH02 8-channel chassis and power supply with a chosen assembled preamp module and matching faceplate, ready to use on arrival. Available with T15 ($549), S90 ($679), C84 ($689), A12B ($719), N72 ($849), or J99 with SC90 opamps ($929).
• SC90 (John Hardy 990C-Style Op-Amp) Seventh Circle Audio's version of the John Hardy 990C op-amp, providing the same dynamics and low noise as the original; used in J99 preamp modules. Sold standalone at $45 each.
• Colored Knobs Replacement colored knobs for SCA preamp and filter modules, available in 9 colors to identify channels. Black knobs ship standard with each module; colored knobs sold separately at $4 each.
• Divider Panel for CH02 Chassis Steel divider panels that install between modules in the CH02 chassis to reduce crosstalk and EMI; up to 7 dividers per chassis, recommended between transformer-equipped modules such as N72, A12, and J99 for magnetic isolation. Priced at $15 each.
• CH02-SP Faceplate Subpanel Modular subpanels for the CH02 chassis that ease assembly and identify each installed module; blank subpanels cover positions not yet filled, required for CH02 chassis installation and not compatible with CH01, 500 Series, or PC01. Priced at $15 each.
• Preamp Calibration / Factory Test Service Factory calibration and testing service for assembled SCA preamp or filter modules, including proper calibration, full testing, and return shipping within the US (international customers pay full return shipping). Priced at $50 per module.

Quantifiable outcome

• Products in daily use by recordists world-wide
• +1 more outcomes

Named customers5 records

Segments4 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature6 records

Scale indicators3 records

Recent moves5 records

Expansion highlights5 records

Broad incumbents

• API Audio: API is the original maker of the API 500 Series format and the API-style preamp circuits that the SCA A12B explicitly clones, putting it at the top of the same product category.
• Solid State Logic (SSL): SSL is the originator of the SSL 9000 console sound that the SCA S90 module clones, and competes at the high end of the same pro-audio preamp market.
• Universal Audio: Universal Audio is the dominant brand in modern pro-audio interfaces and analog outboard preamps (e.g., Apollo, 610, LA-610), competing broadly for the same recording-studio budget even though its analog line is higher-priced than SCA.
• AMS Neve: AMS Neve is the original manufacturer of the Neve 1073/1272-style circuits that the SCA N72 module clones, sitting at the premium end of the same category.

Direct peers

• Chandler Limited: Chandler Limited produces EMI/Neve- and Abbey Road-style pro-audio outboard gear, sharing SCA's design language of recreating classic console circuitry for the recording market.
• Warm Audio: Warm Audio manufactures affordable clones of classic Neve, API, SSL, and other vintage pro-audio preamps and compressors, mirroring SCA's value-tier positioning around boutique transformer-based designs.
• Heritage Audio: Heritage Audio builds modern interpretations of classic Neve, API, and SSL-style pro-audio gear targeted at project and professional studios, directly overlapping SCA's transformer-coupled preamp category.
• Radial Engineering: Radial Engineering sells a broad pro-audio catalog including DIs (D11 direct competitor), preamps, and 500 Series modules, with overlapping studio and live-sound customers to SCA.
• BAE Audio: BAE Audio makes high-end Neve- and API-style preamps and EQs for professional studios, occupying the same boutique 'vintage circuit recreation' niche that SCA addresses at lower price points.
• ART Pro Audio: ART Pro Audio sells affordable tube and solid-state preamps plus a 500 Series lineup aimed at project and home studios, directly comparable to SCA's value-tier analog offerings.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks7 records

Key highlights7 records

Customer concentration

• Facebookfacebook.com/103863784751130
• Instagraminstagram.com/seventhcircleaudio
• LinkedInlinkedin.com/company/seventh-circle

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Seventh Circle Enterprises