I purchased this one new and used it gently in my smoke free home studio.  Outstanding on vocals, acoustic instruments, hand percussion, etc.... You can't beat the ISA preamps for subtle character and punch. This one is mint and  includes manual, power cord and original box.
From the Focusrite site -
Classic mic pre with independent DI

Featuring a rugged, portable all-metal enclosure, ISA One combines the classic Focusrite microphone preamp with a flexible, independent DI channel and optional 192kHz precision A-D conversion. 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.

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 Dedicated insert point specifications Mic Input Response

Gain range (Mic)

0dB to 60dB in 10dB steps 20 dB of variable gain

EIN (Mic)

-126dB measured at 60dB of gain with 150 Ohm terminating impedance and 22Hz/22kHz band-pass filter

Noise (Mic)

Noise at output with unity gain (0 dB) and 22 Hz-22 kHz band pass filter-97 dBu

Signal-to-Noise Ratio (Mic)

106 dB relative to max headroom (9dBu)

Frequency Response (Mic)

At minimum gain (0 dB)-0.5dB down at 10Hz and -3dB down at 125kHz

CMRR (Mic)

98dB (Channel 1, 1kHz, maximum gain with 24 dBu input)

Crosstalk Channel to Channel (Mic)

With 10dB@1kHz input to chA, chB output =104dBrA. With 10dB@10kHz input to chA, chB output = 84dBrA

Line Input Response

Gain range (Line)

-20dB to 10dB in 10dB steps 20 dB of variable gain

Input Impedance (Line)

10 kO from 10 Hz to 200 kHz

Total Harmonic Distortion Noise (Line)

Measured with a 0 dBu input signal, and a 22 Hz-22 kHz band pass filter0.0001

Frequency Response (Line)

At unity gain (0 dB)-0.3dB down at 10Hz and -3dB down at 200kHz

Instrument Input Response

Gain range (Instrument)

10dB to 40dB continuously variable

Input Impedance (Instrument)

High = greater than 1M Low =greater than 300k

THD (Instrument)

At minimum gain ( 10)

High-Pass Filter


18 dB per octave (3 pole filter)


Fixed 75Hz measured at the 3dB down point

Weight and Dimensions

W x D x H

220mm (W) x 104mm (H) x 254 - 290mm


3.9 kg (8.6 lbs)

Listed6 months ago
ConditionMint (Used)
Mint items are in essentially new original condition but have been opened or played.learn more
  • ISA One Desktop Mic Preamp
  • Blue
  • 2008 - Present
Made In
  • United Kingdom

Reverb Protection

Simple Returns, Secure Transactions, Human Support

Learn more

Secure Checkout

Randy's Gear Outlet

Eatontown, NJ, United States
Joined Reverb:2018

Reverb Gives

Your purchases help youth music programs get the gear they need to make music.

Carbon-Offset Shipping

Your purchases also help protect forests, including trees traditionally used to make instruments.

Oops, looks like you forgot something. Please check the fields highlighted in red.