Focusrite Pro ISA One Analogue Microphone Preamp
Classic single-channel Microphone Preamp with independent DI
The ISA One microphone preamplifier delivers Focusrite's prestigious ISA transformer-based preamp in a rugged and portable chassis, at a groundbreaking price. ISA One features the classic vintage microphone preamplifier topology from the original ISA110 module, which formed the cornerstone of each channel of Focusrite's legendary Forté console. The preamp is complemented by a line input and an independent D.I. channel, complete with dedicated gain control, active or passive impedance switch, a TRS Jack output for routing to an amp and an independent XLR output on the rear.
Focusrite’s ISA One microphone preamplifier supplies the brand’s esteemed ISA transformer-based preamp at an industry leading price in a robust and mobile chassis. ISA One delivers the definitive vintage microphone preamplifier topology from the innovative ISA110 module, which served as the cornerstone for every channel of Focusrite's critically acclaimed Forté console. The preamp is harmonised by a line input and an independent DI channel, complete with devoted gain control, active or passive impedance switch, a TRS Jack output for routing to an amp and an autonomous XLR output on the rear.
This adaptable independent DI means that the ISA One is perfectly suited both for demanding performers who need a single classic solution for both guitar and vocals and engineers wanting to blend a DI’d guitar signal with a mic’d guitar cabinet.
The user has the capacity to alternate between four carefully selected input impedance settings, thanks to an additional variable impedance circuit. On top of the foundation ISA110 impedance, three extra impedance settings create the possibility for perfect matching, or creative mismatching of the preamp with any microphone. ISA One also includes an insert point, if the need arises to place extra processing between the preamp or DI and the optional converter. Phantom power, phase reverse and a 75Hz, 18dB/octave high-pass filter are also available from the angled front panel.
Independent input metering for each channel is delivered in the form of a moving coil VU meter with variable calibration to suit analogue and digital recording media, as well as two six-LED peak meters; inputs can be metered either pre- or post-insert. The meter calibrations use all the same reference points as Avid's Pro Tools HD system, allowing seamless line-up.
ISA series transformer-based preamplifier: Encased in a rugged and portable chassis, ISA One offers the classic Focusrite microphone preamplifier at its lowest cost to date
Flexible independent D.I. channel: ISA One is ideal for both engineers and demanding performers alike, featuring independent gain control, an output for routing to an amp, an independent XLR output on the rear and routing to the optional A-D converter
Switchable impedance: Choose one of four carefully selected input impedances, including the original ISA110 setting, to suit any microphone
Headphone output with volume control: ISA One can feed either a sum of the two inputs to the headphones output, or an external stereo cue mix (such as a stereo mix feed from an interface) via two TRS Jack inputs on the rear of the unit
Dedicated insert point: Allows you to place extra processing between the preamplifier or D.I. and the optional converter, such as an EQ or compressor
Optional stereo 192kHz A-D converter: You can choose to upgrade your unit with an optional digital card that delivers the best A-D performance in its class (dynamic range of 118dB). Alternatively, the ISA One Digitalcomes with the A-D converter as standard.
Mic Input Response
Line Input Response
Instrument Input Response
High Pass Filter
0 = +22dBu
-2 = +20dBu
-6 = +16dBu
-12 = +10dBu
-18 = +4dBu
-42 = -20dBu
Analogue Channel Inputs
Analogue Channel Outputs
Analogue Channel Additional I/O
Dimensions and Weight