Focusrite
Focusrite ISA Two Classic Dual Mono Transformer Based Microphone Preamp
Best dual-channel preamp for professional studios seeking classic, versatile sonic character.
Experience classic Focusrite sound with the ISA Two, a professional dual-channel microphone preamplifier module. Built around the renowned ISA architecture and featuring a high-quality Lundahl transformer, it delivers exceptional audio fidelity. The ISA Two offers extensive control, including variable impedance selection and up to 80dB of gain, making it ideal for matching a wide range of microphones. Its robust 1U rack-mountable design ensures reliability in professional studio environments, providing pristine amplification for demanding applications.
$999.99
Owner Satisfaction
4.7
/ 5
Category Rank
22
/ 87
#22 in Microphone Preamps
Price vs Category Average
-38%
Below average
Channels
2
Who it's for
- Engineers seeking the iconic vintage console sound
- Producers needing precise tonal control for various microphones
- Studio owners requiring high-quality stereo tracking in one rack
Who should skip it
- Budget-conscious hobbyists building a home studio
- Users wanting an all-in-one digital recording solution
- Engineers requiring fast, precise peak level monitoring
Performance breakdown
Sonic Character
The Lundahl transformer delivers that legendary, rich Focusrite studio warmth.
Gain Versatility
With 80dB on tap, it handles even the quietest ribbon microphones effortlessly.
Impedance Flexibility
Variable settings allow you to perfectly tune the preamp to any microphone.
Signal Clarity
Extremely low noise floor ensures your recordings remain pristine and professional.
Build Quality
A rugged, rack-mountable chassis built to survive years of studio abuse.
Input Versatility
Dedicated DI inputs make tracking instruments direct simple and high-fidelity.
Key Specs
Channels
2
Maximum Gain
80dB (Mic Input)
Transformer
Lundahl LL1538
Variable Impedance
600Ω / 1400Ω / 2400Ω / 6800Ω
THD + N
<0.0007% @ 1kHz
EIN
-127dB @ 60dB / 150Ω
Dimensions
480W x 44H x 280D (mm)
Weight
3.7kg
Features
- Dual-channel ISA Transformer Preamp
- Classic Focusrite sonic character
- Variable impedance for mic matching
- High-pass filter with variable cutoff
- Dedicated Instrument/DI input
- Low noise floor for pristine signal
- Robust 1U rack-mountable chassis
What customers say
The Focusrite ISA Two is widely acclaimed as a professional preamp delivering the signature Focusrite sound, largely due to its dual-mono design and Lundahl transformers. Users consistently praise its exceptional sonic clarity, high headroom, and ability to add subtle warmth when pushed. A key feature is the variable impedance control, which engineers find invaluable for perfectly matching the preamp to any microphone type, optimizing tone, especially for vintage or low output models. Build quality is robust and studio ready. While a significant purchase, the consensus is that the superior sonic depth and professional features fully justify the investment, making it a foundational tool for serious recording.
Know before you buy
Variable impedance allows you to change how the preamp interacts with your microphone's output. By switching between the four settings, you can subtly alter the frequency response and character of your mic, letting you 'tune' the sound to better suit a specific vocal or instrument.
Yes, the unit features dedicated front-panel instrument inputs. These high-impedance DI inputs are designed to capture the full frequency range of passive pickups without the signal loss or dullness often associated with standard line inputs.
The ISA Two offers up to 80dB of gain, which is more than enough to drive low-output ribbon microphones or quiet dynamic mics. Its low noise floor ensures that even at high gain settings, your signal remains clean and free of unwanted hiss.
The unit is a standard 1U rack-mountable device. It measures 480mm wide and 280mm deep, so it will fit comfortably into any standard 19-inch studio equipment rack.
The Lundahl LL1538 is a high-quality input transformer that is central to the 'classic' Focusrite sound. It provides the warmth, harmonic richness, and transient response that define the ISA series, distinguishing it from transparent, transformerless preamps.
The high-pass filter is independently adjustable for each channel, allowing you to roll off unwanted low-end rumble or mud before the signal hits your converter. It is a useful tool for cleaning up vocal tracks or acoustic instruments during the initial recording stage.
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