Microphone Preamps
A12
The A12 is a simple, single stage preamp roughly based on classic American designs of the early '70s. Built with the suggested transformers and op-amp, the result is an amplifier with an aggressive midrange and pronounced transformer coloration. The A12 sounds fantastic with rock drums and electric guitars, but is versatile enough to be used with a wide variety of source material and microphone combinations. The A12 is easy to build and makes a great project for less-experienced DIYers.
SC10 or SC25 op-amp must be ordered separately.
CH02-SP-A12 subpanel must be ordered separately.
$249
92 can ship in 1 to 2 weeks
A12 1 m
A12B
Like the A12, the A12b delivers an aggressive, immediately recognizable midrange with pronounced transformer coloration. The circuit is exactly the same as the A12 and sounds identical, but the op-amp is not modular. Available as an assembled module only.
CH02-SP-A12 subpanel must be ordered separately.
$299
17 can ship in 3 to 5 days
A12b 1 m
C84
The SCA C84 is a transformerless microphone preamp based on the "Double Balanced" circuit first published in 1984 by Graham John Cohen and since used by many notable manufacturers. The C84 is superb on acoustic instruments, percussion, and any source that needs to be captured as accurately as possible. The C84 is also inexpensive and easy to build.
This kit uses surface mount parts and is intended for experienced builders.
CH02-SP-C84 subpanel must be ordered separately.
$199
14 can ship today
C84 1 m
J99
The SCA J99 is a flexible, high-gain, low-noise, low-distortion microphone preamplifier, based on the classic Jensen Twin Servo design. This is a great preamp to use when a neutral sonic character is required, but the slightest amount of euphonic transformer coloration is desired.
990C-style op-amps must be ordered separately.
CH02-SP-J99 subpanel must be ordered separately.
$329
4 can ship today
J99 1 m
J99B
The SCA J99B is a flexible, high-gain, low-noise, low-distortion microphone preamplifier, based on the classic Jensen Twin Servo design. This is a great preamp to use when a neutral sonic character is required, but the slightest amount of euphonic transformer coloration is desired.
Not available as a kit!
CH02-SP-J99 subpanel must be ordered separately.
$479
Please email for lead time
J99b 1 m
N72
The N72 delivers the unmistakable character of the highly sought-after Neve single-ended, class A, transformer-coupled console modules. The N72 has become especially popular with digital recordists, since many feel it provides a certain warmth and color that can greatly benefit the hyper-accurate quality of digital recording. The basic circuitry of the N72 is essentially the same as that of the BA183 modules used in the 1272, 1073, and other Neve modules, and from a sonic perspective is virtually indistinguishable from an original Neve.
Intended for experienced kit builders only!
CH02-SP-N72 subpanel must be ordered separately
$329
71 can ship in 1 to 2 weeks
N72 1 m
T15
The SCA T15 is a transformerless microphone preamplifier designed around the excellent THAT Corporation 1512 and 1646 ICs. These state-of-the-art chips enable the performance of the T15 to approach that of sophisticated discrete and hybrid designs (such as the C84) while using far fewer components. While it does not have the same headroom and output drive capability as the C84, the T15 has similar noise and distortion specifications and excels in the same applications. Unlike the C84, the T15 has a small number of components, requires no adjustment or trimming, and is very easy to assemble.
CH02-SP-T15 subpanel must be ordered separately.
$99
6 can ship today
T15 1 m
DI
D11
The SCA D11 is a two-channel active DI that accepts a high-impedance, unbalanced, instrument-level input and produces a low-impedance, balanced, mic-level output. An optional Jensen or Cinemag transformer can be fitted to provide a fully floating isolated output if required. The D11 has a small number of components, requires no adjustment or trimming, and is very easy to assemble.
CH02-SP-D11 subpanel must be ordered separately.
$79
17 can ship today
D11 1 m
Compressor
B16
Versatile, transparent VCA compressor tames unruly dynamics. Features program-dependent attack and release, up to 60dB of compression, and +/-24dB of makeup gain. Optional output transformers provide for superior isolation and euphonic coloration if desired.
CH02-SP-B16 subpanel must be ordered separately.
$159
7 can ship today
B16 1 m
Discrete Op-Amps
SC10
The SC10 is our "slightly improved" version of the Quad-Eight AM10 discrete op-amp. An all-discrete 13 transistor design, the SC10 retains the slew rate, bandwidth, and high output current capability of the original.
$79
1 can ship today
Sc10 big
SC25
The SC25 is an updated, "slightly improved" version of the API 2520 discrete op-amp. This all-discrete 13 transistor design retains the original's basic topology but uses a different compensation scheme, adds improved current sources, and employs more modern transistors throughout. The SC25 is best used in circuits with medium to high source impedance and with mic input transformers with 1:8 or higher turns ratios
$79
17 can ship today
Sc25 big
Chassis
CH02
The CH02 is a road-worthy 2RU chassis designed to hold up to eight Seventh Circle modules in any combination. High voltage supply rails enable more headroom than any 500-series rack. Illuminated logo indicates +30V, -30V, and +48V health.
$499
2 can ship in 3 to 5 days
Ch02 1 m
PC01
Get any preamp module fully assembled and ready to record in the rugged, compact, and affordable OneShot 1/4U chassis. Easy tabletop or rack mount configuration - fit four on a single Raxxess UNS-1 shelf. Includes 115VAC wall-mount transformer.
PC01KF sold as-is with no warranty or support whatsoever.
$399
Please email for lead time
Oneshot 1 m
Subpanel
CH02
Modular subpanels ease assembly and identify each module installed in the chassis. Add blanks for the positions you haven't filled yet. Subpanels fit the CH02 only.
$15
Please email for lead time
Ch02 sp 1 m