Focusrite ISA 828 MkII — an eight-channel microphone preamp with a Lundahl LL1538 transformer on every input, built as a permanent rack fixture that every source can stay connected to at once.
Each channel has separate mic and line connectors, with channels 1-4 adding a front-panel instrument input — every source stays plugged in simultaneously, with nothing to repatch between sessions. An efficient switching power supply keeps the unit cool under continuous use, and the optional ISA ADN8 card adds eight Dante, ADAT and AES3 outputs at up to 24-bit/192 kHz and 122 dB of dynamic range.
Eight input jacks, all permanently connected
Dedicated mic and line connectors on every channel remove the need to swap a single combo jack between sources — a microphone, a line feed from a console, and an instrument can all stay wired in, with input selection just a front-panel button press. That makes ISA 828 MkII a fixture in the rack rather than a device to unplug and replug for every session, which matters especially for mobile rigs and studios with rotating clients.
80 dB of gain and switchable impedance for any microphone
Four input impedance settings — from 600 Ohms through the original ISA 110 value (1.4 kOhms), 2.4 kOhms, up to 6.8 kOhms — let you tailor tonal character to a specific microphone instead of settling for one compromise setting across every source. Stepped gain up to 60 dB plus a continuously variable +20 dB trim give 80 dB of headroom on the mic input and 30 dB on line, and a switchable insert on every channel lets you patch in a compressor or EQ ahead of conversion — including when the unit runs digitally with the ADN8 card, where the analogue outputs double as insert sends.
KEY FEATURES
- 8 preamps with a Lundahl LL1538 transformer on every input
- Dedicated mic and line connectors on every channel, DI on channels 1-4
- 4 input impedance settings, including the classic ISA 110 value
- Gain up to 60 dB in 10 dB steps plus a continuously variable +20 dB trim (up to 80 dB on mic)
- High-pass filter, 75 Hz, 18 dB/octave
- 6-segment LED metering per channel, calibratable
- Switchable rear-panel insert on every channel
- Analogue output via 8x DB25
- Switching power supply — quiet, cool continuous operation
- Optional ISA ADN8 card: Dante, ADAT, AES3 up to 24-bit/192 kHz
TECHNICAL SPECIFICATIONS
- Channels: 8 independent microphone preamps
- Inputs: 8x XLR (mic), 8x TRS (line), 4x TS (instrument, channels 1-4)
- Mic gain: up to 60 dB in 10 dB steps + 0-20 dB trim
- Instrument gain: 10-40 dB (channels 1-4)
- Input impedance (mic): 600 Ohms / 1.4 kOhms (ISA 110) / 2.4 kOhms / 6.8 kOhms
- HPF: 75 Hz, 18 dB/octave
- Frequency response: 10 Hz-122 kHz
- Analogue outputs: 8x via DB25 connector
- Optional A-D conversion: 24-bit/192 kHz, 122 dB dynamic range (ADN8 card)
- Dimensions: 3.5 x 19 x 12.8 in (2U)
- Warranty: 3 years



