ISA Two: you may only need a couple of mic preamps – but they should be the best.
The ISA Story goes back to 1985, when Sir George Martin commissioned legendary designer Rupert Neve to design new modules for the console at AIR Montserrat. They were so successful that more were commissioned for AIR London. These original modules form the basis of today’s Focusrite ISA range – delivering the legendary Focusrite sound to leading studios, artists, producers and engineers around the world. Literally hundreds of hits have been made with the Focusrite ISA Range – and continue to be made today.
Focusrite’s ISA Two brings together a totally independent pair of legendary ISA microphone preamps inspired by the original ISA 110 module, combining the best of traditional solid-state electronics with the original input transformer specified by Rupert Neve – the Lundahl LL1538. Two is a nice round number – ideal for recording, say, a vocal and an instrument, or a stereo piano. But though you may only need two mic pres, you owe it to your craft to choose the best. (And if you need more, we offer ISA 428 Mk II 4-channel and ISA 828 8-channel units too.)
Focusrite has made one little adjustment to the mic pre. The original ISA 110 had a single input impedance that was ideal for the mics of the time. In the ISA Two there are three more, allowing you to get the very best out of any microphone, vintage or modern. Give a vintage mic the input it expects to get a traditional, warm sound. Pair the ISA Two with modern microphones and get the most transparent sound imaginable. Or experiment and pull out the inner character of any microphone you care to try. Couple that with up to 80dB of gain and you can be ready for anything.
In addition to the mic pres, there are front panel instrument inputs for instant access, along with rear-panel line ins. There’s also a balanced insert point on the rear panel, actuated with a front-panel button so you can insert the EQ, dynamics or other processors you need. Add to that the user-calibrated 8-LED metering and variable cutoff high-pass filter and you know that with the ISA Two you’ll have everything you need to get the highest quality sound into your recordings.
Lundahl LL1538 mic input transformer
Rupert Neve originally chose the Lundahl LL1538 to be the input transformer on the ISA 110. It remains the best microphone input transformer available, and is used in every ISA Series mic pre.
Up to 80 dB of gain
ISA Two offers up to 80 dB of clean, distortion-free gain. The much-heralded ISA topology also ensures low noise, even at the highest gain levels. The transformer supplies 20 dB of gain, while ISA's input stage offers up to 60 dB in addition, giving a total of up to 80 dB of maximum gain on the microphone input.
Variable input impedance
Four choices of input impedance, including the original ISA 100 value, allow you to match the preamp to your microphone, even if it's a vintage type, giving you the best possible sound. The impedance is selected using a switch on the front panel, and the impedance choice is remembered even once the unit is switched off and back on.
Each channel has an eight-LED array to clearly display the level of your two signals. Line up your ISA Two levels to match your DAW converters with the calibration knob on the rear panel.
Front panel instrument and rear panel line inputs
Two 1/4in. jack sockets on the front panel of ISA Two give you instant access to a transparent DI input. TRS line inputs are available on the rear panel too, and you can step through them instantly to select the one you want.
Variable cut-off high-pass filter
Built in, and easily accessed with its own large knob and illuminated button, is an extremely smooth sounding 18dB/octave high-pass filter of the same design as the original ISA 110 module. This is ideal for cutting out rumble, thumps and other unwanted low-frequency sounds and with a range of 16 to 420 Hz, it's easy to lose what you don't want, and keep what you do.
Rear panel balanced inserts
Each channel of ISA Two has its own balanced insert point. With 1/4in. TRS send and receive connections, your choice of signal processor can be connected and switched in and out using the illuminated switch on the front panel.