Mic Input Response
• Gain range = 0dB to 60dB in 10dB steps + 20 dB of variable gain
• Input Impedance, variable as follows:-

(Switched Impedance setting Equivalent Input Impedance at 1kHz)

Low = 600 Ohms
ISA110 = 1400 Ohms
Med = 2400 Ohms
High = 6800 Ohms

• EIN (equivalent input noise) = -126dB measured at 60dB of gain with 150 Ohm terminating impedance and 22Hz/22kHz band-pass filter
• Noise at main output with gain at unity (0dB) = -97dBu measured with a 22Hz/22kHz band-pass filter
• Signal to noise ratio relative to max headroom (9dBu) = 106dB
• THD at medium gain (30dB) = 0.0009% measured with a 1kHz -20dBu input signal and with a 22Hz/22kHz band-pass filter
• Frequency response at minimum gain (0dB) = -0.5dB down at 10Hz and -3dB down at 125kHz
• Frequency response at maximum gain (60dB) = -3dB down at 16Hz and -3dB down 118kHz
• CMRR=98dB (Channel 1, 1kHz, maximum gain with +24 dBu input)
• Crosstalk Channel to Channel: with 10dB@1kHz input to chA, chB output =104dBrA. With 10dB@10kHz input to chA, chB output = 84dBrA


Line Input Response
• Gain range = -20dB to +10dB in 10dB steps + 20 dB of variable gain
• Input Impedance = 10kΩ from 10Hz to 200kHz
• Noise at main output with gain at unity (0dB) = -96dBu measured with a 22Hz/22kHz band-pass filter
• Signal to noise ratio relative to max headroom (24dBu)=120dB
• Signal to noise ratio relative to 0dBFS (+22dBu) = 118dB\
• THD at unity gain (0dB) = 0.001% measured with a 0dBu input signal and with a 22Hz/22kHz band-pass filter
• Frequency Response at unity gain (0dB) = -0.3dB down at 10Hz and -3dB down at 200kHz


Instrument Input Response
• Gain range = 10dB to 40dB continuously variable
• Input Impedance:
High = greater than1MΩ
Low =greater than 300kΩ
• Noise at minimum gain (+10dB) = -92dBu measured with a 22Hz/22kHz band-pass filter
• Noise at maximum gain (+40dB) = -62dBu measured with a 22Hz/22kHz band-pass filter
• THD at minimum gain (+10dB) = 0.001% measured with a 10dBu input signal and with a 22Hz/22kHz band-pass filter
• Frequency Response at 10dB gain with -10dB input = 10Hz-100kHz +/- 0.6dB
• Frequency Response at 40dB gain with -40dB input = -2.5dB down at 10Hz and 0dB at 100kHz


High Pass Filter
• Roll off = 18dB per octave 3 pole filter
• Fixed Frequency 75Hz measured at the 3dB down point


Meters
• Moving coil (MC) meter is factory calibrated to 0VU = +4dBu with 1kHz sinewave. With the VU Cal button pressed the meter can be adjusted on the rear panel to allow 0VU to equal +10dBu to +26dBu with the centre detent being equal to +22dBu.
• Peak LED meters calibrated in the detent position for 0dBFS = +22dBu, calibration is adjustable on the rear panel to allow 0dBFS to equal +10dBu to +26dBu
• Routing for MC and Peak1 meter is after the HPF, pre insert send or switched post insert return. Peak2 is always pre ADC channel 2, which can be fed by external input or Instrument input.
• LED levels are as follows when peak calibration is set to center detent on the rear panel. (This is when using the internal ADC).

0 = +22dBu
-2 = +20dBu
-6 = +16dBu
-12 = +10dBu
-18 = +4dBu
-42 = -20dBu


FRONT AND REAR CONNECTIVITY

Analogue Channel Inputs:
• Mic input: XLR x 1
• Line input: XLR x 1 and TRS x1
• Instrument input TRS Jack: XLR x 1
• External ADC input: TRS Jack x 1
• Return: TRS Jack x 1

Analogue Channel Outputs:
• Send: TRS Jack x 1
• Balanced line output: XLR x 1
• DI output: XLR x 1
• DI through: TS Jack x 1

Analogue Channel Additional I/O:
• Cue mix left input: TRS Jack x 1
• Cue mix right input: TRS Jack x 1
• Headphones output: Ό” TRS Jack x 1

Weight
• 3.9kg
• 8.6Ibs

Dimensions
• 220mm (W) x 104mm (H) x 254 - 290mm (D - top to bottom)
• 8.66" (W) x 4.1" (H) x 10" - 11.4" (D - top to bottom)

 

Musictech – Issue 64 – Jul ‘08 - Review Quotes
'This preamp is clean, pure, and transparent, but, like all fine preamps, it can make recordings sound better than ‘reality’.'

'With 80dB of available gain to play with just about any microphone you want and its neutral but ‘enhanced’ sound quality makes it a general-purpose tool rather than a preamp you can only use for those ‘special occasions’. It can also solve monitoring issues as well as providing a fully independent second channel for DI duties.'

'Some engineers maintain that the closer you can get the preamp to the mic the better, so in this respect the ISA One is ideal.'

'Why Buy? Pristine sound quality, Versatile connectivity, Impedence switching, Excellent metering, Huge gain level, Low noise, Onboard monitoring, and competitively priced.'

Amazona.de - German Webzine – Jul ‘08 - Review Quotes (Translated from German)
'All the Legendary superbness of an ISA for less than 1.000,-€ unimaginable to date.'

'Thanks to excellent technology and switchable impedance it's a perfect match to any mic.'

'Legendary, well engineered'


Soundcheck.de - German Webzine – Jul ‘08 - Review Quotes (Translated from German)
‘The ISA One emerges as a candid pre-amp which gains the signal in a natural way without changing the original character of the sound.’

‘In no time at all the ISA One is ready for use; it keeps all promises regarding sound. The results in recording session tests have produced crystal clear vocals, even with the proximity effect the sound is consistent and differentiated.’

‘The same can be said for the ISA Ones performance with acoustic instruments, guitars keep their natural brilliance in high frequencies and low frequencies remain firm and clear.’

‘Our overall impression of the ISA One is that it has a warm sound which stands head and shoulders above the rest of other audio interfaces for use with your computer.’

‘Focusrite's ISA-One is an all-round solution in the studio, which enhances every signal. Backside connections leave nothing to be desired and feature a connection to every plug in use.’

‘Thanks to a couple of options, all types of mics are realisable. The ISA One is unbeatable in use with different mics.’

Resolution - Volume 5 – Jul/Aug ‘08 - Review Quotes
'The look and feel of many of the front panel controls will be utterly familiar to anyone who has used other units in the ISA range, and the core of the unit is very straightforward.'

'The DI section remains active and has it's own dedicated balanced output on the rear of the unit. This means that a DI source could be recorded via this output, while the pass-through is sent to an amp. A mic on this amp could then run through the mic pre, which feeds its own, separate output. In this kind of situation, the metering provided is quite comprehensive.'

'In use, the sound of the unit will yield no surprises to anyone who has used other devices in the ISA range. The mic pre is quiet, clean and nicely neutral with just a touch of HF brightness.'

'The switchable input works well too, with the lowest settings able to pull some additional LF weights out of dynamic and ribbon microphones.'

'The DI stage impressed me as much as anything else - my current favourite is a Radial JDV, and the ISA Ones DI matched it in most respects.'

'As a solution to minimum signal path recording of guitars it works well particularly for recording both a DI and mic feed, and if you're short on decent headphone foldback amps, it has it's uses here too.'