FOCUSRITE / ISA428 mkII 4-channel microphone preamp

Like the original ISA110, this 4-channel microphone preamplifier features a dual gain circuit using an input transformer, which is the essence of Focusrite, and fully inherits the high-fidelity, transparent ISA sound.

~From the distributor's website~

■The ISA428 MkII is a head amplifier featuring four microphone inputs and eight line inputs, incorporating the traditional transformer inputs of the ISA 110 module, inherited from the Focusrite Forte console. It maintains the same mixing console-quality circuit design while achieving an affordable price. With features like variable input transformer impedance switching to maximize microphone response and an optional 8-channel high-quality AD converter, the ISA428 MkII is the perfect front end for professional recording.

■Since its release in 1985, the ISA110 microphone preamps have been acclaimed for their warm, transparent sound using Lundahl L1538 transformers. To further enhance sound quality, the ISA428 MkII now offers four impedance settings (600Ω, 1400Ω, 2400Ω, and 6800Ω) to maximize the performance of your connected microphones. Thanks to its solid fundamentals and steady evolution, the ISA series continues to enjoy overwhelming support. The optional 192kHz 8-channel AD converter is the same as the ISA828. It digitally converts signals from four mic & instrument inputs or line inputs and four line inputs.

■Four instrument inputs for guitars and other instruments are located on the front panel, allowing direct connection without the need for separate D.I.s. In addition, channels 1 through 4 have insertion points, allowing you to insert a compressor or EQ.

■Features
-Four mic preamps using the ISA series' traditional Lundahl L1538 transformer
Mic preamps using the Lundahl L1538 transformer input have reigned as a recording standard for many years, and their sound can be heard on countless songs.・8-Channel 192kHz/24-bit AD Converter (Optional)
The optional AD converter has a dynamic range of 120dB at a sampling frequency of 192kHz and jitter of just 250 picoseconds.


・Four-Stage Impedance Switching Function
Four stages of impedance switching are available: Low: 600Ω, ISA110: 1400Ω, Mid: 2400Ω, and High: 6800Ω, allowing you to select the optimal input impedance for your microphone. This allows you to obtain optimal sound with any microphone, from the latest condenser microphones to vintage ribbon microphones.


・Front-Panel Instrument Input
You can connect a guitar or other instrument directly without using a D.I. box.


・Insert Points
Each channel has an insert point, allowing you to insert a compressor or EQ. Variable High-Pass Filters
Each channel is equipped with a high-pass filter, which, like the original ISA428, can be used with an 18dB/octave range and a 16Hz to 420Hz frequency range.

Highly Visible LED Peak Meters
Each channel is equipped with a fast-responding 6-point LED peak meter, allowing for accurate monitoring of output levels.

Phantom power provided on each channel

■Dimensions: 88mm (H) x 480mm (W) x 280mm (D)
■Weight: 5.5kg

*Compared to the previous model, the ""ISA428 Pre Pack""
The new ""ISA428 MkII"" omits three features: input VU meter, ADC soft limiter, and ADC bit depth switching.