Seventh Circle Audio J99 (SC90)
Jensen Twin Servo / John Hardy 990C-style discrete op-amp mic preamp module
Preamp$449Manufacturer list price
Specifications
- Type
- Preamp
- Description
- Jensen Twin Servo / John Hardy 990C-style discrete op-amp mic preamp module
- Topology
- Transformer-coupled, discrete op-amp (Jensen Twin Servo / John Hardy 990C-style), JLM/Jensen lineage
- Signal path
- Analog
- Channels
- 1
- Channel format
- mono mic/line preamp
- Form factor
- module (SCA proprietary format)
- Connection
- SCA proprietary module format (CH02/PC01 chassis)
- DSP
- false
- Powered
- true
- Impedance (Ω)
- 300 (jumpered, max-gain configuration)
- Country of manufacture
- USA
- Phantom power
- 48V
Details
Controls: 12-position Grayhill stepped gain switch (15-70dB in 5dB steps), gain trim (up to 6dB cut), phase reverse switch, phantom power switch
I/O: Neutrik PC-mount XLR mic/line I/O; requires separately-ordered CH02-SP-J99 subpanel; uses SC90 (John Hardy 990C-style) discrete op-amp
Notes: Clones Jensen Twin Servo / John Hardy 990C-style discrete-op-amp preamp topology (JLM/Jensen family). Lundahl 1538XL input transformer, CineMag CMOB-2H output transformer. EIN approaching -130dB (as published). Available as DIY kit or assembled (single listed price; SC90 opamp option noted as sometimes unavailable). SCA proprietary format -- fits SCA CH02/PC01 chassis only, NOT API 500-series (see J99-500 for that version).