The ISA One microphone pre-amplifier delivers Focusrite's prestigious ISA transformer-based pre-amp in a rugged and portable chassis, at a groundbreaking price.And now you can add the iconic sound, feel, and styling of the legendary Focusrite console to your production toolkit simply by registering your ISA One. The Bx_console Focusrite SC is a virtual channel strip from the original console featuring the ISA 110 EQ and ISA 130 dynamics module including the compressor/limiter, expander/gate, and de-esser. The plugin is an SC VST/AU/AAX compatible plug-in for Mac and PC, and yours for free upon registration, a $349 value!ISA One features the classic vintage microphone pre-amplifier topology from the original ISA110 module, including the Lundahl L1538 transformer and bespoke zobel network. (The original 110 preamp formed the cornerstone of each channel of Focusrite's legendary Forte console.)The pre-amp is complemented by a line input (XLR and TRS Jack) 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. This flexible independent D.I. makes the ISA One ideal both for engineers wishing to blend a D.I.’d guitar signal with a mic’d guitar cabinet, and for demanding performers who require a single classic solution for both guitar and vocals.A variable impedance circuit has been added, allowing the user to switch between four carefully selected input impedance settings. In addition to the original ISA110 impedance, three further impedance settings allow perfect matching or creative mismatching of the preamp with any microphone. ISA One also features an insert point, should the need arise to place extra processing between the pre amp or D.I. and the optional converter. Phantom power, phase reverse, and a 75Hz, 18dB/octave high-pass filter are also available from the angled front fascia.Independent input metering for both channels is provided in the form of a moving coil VU meter with variable calibration to suit analog and digital recording media, alongside two six-LED peak meters; inputs can be metered either pre- or post-insert. The meter calibrations utilize all the same reference points as AVID's Pro Tools HD system, allowing an effortless line-up.ISA One’s headphone output features a dedicated volume control, which delivers an external stereo cue mix, (a simple click track, or a stereo mix feed from an interface or a live console,) fed to the headphones via two TRS jack inputs on the rear of the unit.An optional state-of-the-art stereo A-D converter is also available (the same card as used with the ISA430 Mk II), embodying cutting-edge conversion technology seated within Focusrite’s custom analog circuitry. This optional card can be retrofitted at any time and provides two channels of 24 bit/192kHz A-D conversion with a dynamic range of 119dB.FeaturesISA Series Transformer-based Pre-amplifierFlexible Independent D.I. ChannelSwitchable ImpedanceOptional Stereo 192kHz ADCHeadphone Output with Volume ControlDedicated Insert PointSpecificationsMic Input Response:Gain Range: 0dB to 60dB in 10dB steps +20dB of variable gainInput Impedance, variable as follows: Low = 600Ω ; ISA110 = 1400Ω; Med =2400Ω; High =6800Ω (Switched impedance setting equivalent input impedance at 1kHz)EIN (equivalent input noise): -126dB measured @ 60dB of gain with 150Ω terminating impedance and 22Hz - 22kHz band-pass filterNoise at main output with gain at unity (0dB): -97dBu measured with a 22Hz - 22kHz band-pass filterSignal to noise ratio relative to max headroom (9dBu): 106dBTHD at medium gain (30dB): 0.0009% measured with a 1khz -20dBu input signal and with a 22Hz - 22kHz band-pass filterFrequency response at minimum gain (0dB): -.05dB down at 10Hz and -3dBdown at 125kHzFrequency response at maximum gain (60dB): -3dB down at 16Hz and -3dB down 118kHzCMRR: 98dB (Channel 1, 1kHz, maximum gain with +24dBu input)Crosstalk Channel to Channel: with 10dB @ 1kHz input to chA, chB output = 104dBrA. With 10dB @ 10kHz input to ch A, ch B output =84dBrALine Input Response:Gain range: -20dB to +10dB steps +20dB of variable gainInput Impedance: 10k ohm from 10Hz to 200kHzNoise at main output with gain at unity (0dB): -96dBu measured with a 22Hz - 22kHz band-pass filterSignal to noise ratio relative to max headroom (24dBu): 120dBSignal to noise ratio relative to 0dBFS (+22dBu): 118dBTHD @ unity gain (0dB): 0.001% measured with a 0dBu input signal and with a 22Hz - 22kHz band-pass filterFrequency Response @ unity gain (0dB): -0.3dB down @ 10Hz and -3dB down at 200kHzInstrument Input Response:Gain range: 10dB to 40dB continuously variableInput Impedance: High = greater than 1MΩ; Low = greater than 300kΩNoise @ minimum gain (+10dB): -92dBu measured with a 22Hz - 22kHz band-pass filterNoise @ maximum gain (+40dB): -62dBu measured with a 22Hz - 22kHz ... F