The ISA One combines the classic Focusrite microphone preamp with a flexible, independent DI channel and optional 192kHz precision A-D conversion. Encased in a rugged, portable all-metal enclosure, at the heart of the ISA range is the microphone preamplifier with its Lundahl input transformer – essentially the same circuit, based on the original ISA 110, that has been used for 30 years in successive Focusrite designs. The input transformer imparts a special character to the sound that can't be truly emulated in any other way, while the modern twist of variable input impedance allows for a new degree of flexibility.
Whether you're an artist, engineer or producer, you'll appreciate the versatility of the ISA One, with its front-panel DI input. The DI includes low/high impedance switching and an amplifier output, and its own feed to the optional A-D converter and separate rear-panel XLR output.
Focusrite Pro ISA One Features
- Classic ISA mic preamp design featuring Lundahl LL1538 input transformer
- Flexible independent DI channel
- Switchable input impedance including classic ISA 110 setting
- Headphone output with volume control
- Mic, line, and instrument inputs
- Optional stereo 192kHz A-D conversion card
- 3 Year Warranty
- ISA One preamp1
- Brainworx bx_console Focusrite and RedNet Control software programs1
- Mic input response
- Gain range: 0dB to 60dB in 10dB steps 20 dB of variable gain
- EIN: -126dB measured at 60dB of gain with 150 Ohm terminating impedance and 22Hz/22kHz band-pass filter
- Noise: noise at output with unity gain (0 dB) and 22 Hz-22 kHz band pass filter-97 dBu
- Signal-to-noise ratio: 106 dB relative to max headroom (9dBu)
- Frequency response: at minimum gain (0 dB)-0.5dB down at 10Hz and -3dB down at 125kHz
- CMRR: 98dB (Channel 1, 1kHz, maximum gain with 24 dBu input)
- Line input response
- Gain range: -20dB to 10dB in 10dB steps 20 dB of variable gain
- Input impedance: 10 kO from 10 Hz to 200 kHz
- THD: measured with a 0 dBu input signal, and a 22 Hz-22 kHz band pass filter 0.0001
- Frequency response: at unity gain (0 dB)-0.3dB down at 10Hz and -3dB down at 200kHz
- Instrument input response
- Gain range: 10dB to 40dB continuously variable
- Input impedance high: greater than 1M
- Input impedance low: greater than 300k
- THD: at minimum gain (10)
- High-pass filter
- Roll-off: 18 dB per octave (3 pole filter)
- Frequency: fixed 75Hz measured at the 3dB down point
