McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams

(888) 890-6222

(718) 522-1071

Call Code:


Focusrite ISA428 Channel A/D Option


Dealer for All Products


In The Continental USA


Flexible Return Policy


128 Bit Encryption


Focusrite ISA428 Channel A/D Option

Optional 8 Channel 192kHz A-D Card

Need a Better Deal?Call 718-522-1071

Product Description for the Focusrite ISA428 Channel A/D Option

The ISA features four classic, transformer-based microphone pre amps with switchable impedance and direct Instrument Inputs are combined with an optional eight channel 192kHz ADC. An all-new, Soft Limiter circuit precedes the A/D, providing the perfect path into any DAW, Digital Console or direct to Hard Disc Recorder. The input stage provides enhanced control and creativity allowing you to switch between four carefully selected input impedance settings. The original ISA 110 setting is supplemented by three further impedance settings to either perfectly match the pre-amp with any microphone and maximise level, or to use different settings creatively to shape the sound of the microphone being used. Should the need arise to place extra processing between pre-amp and conversion, insert points are also featured on every channel. Protecting the ADC, Focusrite's Soft Limiter is a new optical circuit design, entirely preventing any digital overs, whilst reducing to an absolute minimum the undesirable distortion artefacts that common limiter circuits typically generate. This limiter requires the optional ADC to be fitted in order for it to operate.

The ADC embodies cutting-edge conversion technology, encompassed within Focusrite circuitry, providing eight high quality conversion channels, at sampling frequency rates of 44.1, 48, 96 and 192kHz. Running at 96kHz allows for up to 16 (2 x 8, parallel) digital outputs. Digital output formats are dual 9-pin D-sub (AES/EBU, SPDIF) and dual ADAT light-pipe.

Full digital metering is provided for every channel, alongside moving coil peak meters, designed to catch even the fastest transients.

A second ISA428 analogue unit can be connected utilising the four extra ADC input channels on the rear of the unit containing the optional ADC. This makes full use of the eight channels provided and expands front-end capacity from four pre amps and eight digital outputs to eight Pre amps and eight digital outputs.


Four ISA-series transformer-based pre-amps
The benefits of Focusrite’s classic pre-amp topology include superb common-mode rejection, an excellent overload margin, an extremely low noise floor and super-wide bandwidth.

Dedicated analogue insert points
Switchable insert points are also featured on every channel, allowing routing (between pre-amp and output) to additional external processing.

Accurate ‘moving coil’ peak meters
Clear metering designed to catch even the fastest and most elusive of transients.

Four front panel instrument inputs
Instant access on the front fascia and no separate DI box required.

Eight line inputs
Four additional A-D converter inputs combine with the four pre-amp inputs to provide eight line inputs, routable discretely to the eight-channel A-D converter option.

Eight Channel optional 192kHz A/D conversion card
With the additional four ADC inputs, two ISA428’s can be used with a single ADC, providing eight channels of pre-amplification, A-D conversion and VU metering.

Custom Global A-D converter ‘soft clip’ limiter
Focusrite’s custom optical design protects the A-D converter by preventing ‘digital overload’. It requires that an A-D converter be installed.

Switchable Impedance
Ideal for mic matching or extended microphone creativity. Settings include the ‘Vintage ISA110’ setting, providing the original Focusrite signature sound.

Variable Focusrite high pass filter
Provided on every channel, this is the same filter as featured on the original ISA110 and the Focusrite forte console.


  • Transformer-based ISA design
  • Gain range: Line = +/- 18dB, Mic = 0 to 60dB (both in 6dB steps), Inst = +10 to +40 dB variable
  • Input impedance: Line = 10k ohm, Mic = Variable - 600, 2k4 and 6k8 ohm + original ISA 110 settings, Inst = >1M ohm

Analogue Performance

  • Noise: Line = -96dB, Mic = -128dB (EIN with 150 ohm input resistance at 60dB of gain)
  • THD: Line = 0.003% with 0dBu, 1kHz input and 20Hz to 22kHz band-pass filter, Mic = 0.003%

Analogue Input and Output connectors (balanced)

  • D.I inputs: 1/4 inch Jack (unbalanced)
  • Mic inputs: XLR (balanced)
  • Line: TRS Jack (balanced)
  • Insert Sends and Returns: TRS Jack (balanced)
  • Additional ADC inputs: XLR (balanced) Line level
  • Analogue Outputs: XLR (balanced)

Digital Output Option

  • AES/EBU and S/PDIF dual 9-pin D-types
  • Optical - ADAT Lightpipe
  • Bit depths 16-, 20- or 24-bit
  • Frequency options 44.1, 48, 88.2, 96, 176.4 and 192kHz
  • Clock options Standard or ?256 x?
  • Meter - 0 dBFS = +22dBu
  • Digital Performance
  • SNR - 120dB A-weighted


  • 7.36kg
  • 16.2Ibs


  • 484mm (W) x 85mm (H) x 250mm (D)
  • 19" (W) x 3.5" (H) x 9.8" (D)
Brand Focusrite
Weight 20.0000
Dimensions (WxHxD) 11.4" x 8.26" x 1.96"
Focusrite ISA428 Channel A/D OptionFocusrite ISA428 Channel A/D Option

Move your mouse over image or click to enlarge

Write Your Own Review

You're reviewing: Focusrite ISA428 Channel A/D Option

How do you rate this product? *

  1 star 2 stars 3 stars 4 stars 5 stars

Deal Request

Focusrite ISA428 Channel A/D Option


Submit the price you are willing to pay for this item.

You will receive a quick response from our crew.

Or just call us now

(888) 890-6222


Newsletter DJ @ You Own Risk Bands/Artists Weekly Production Monthly Consumer Brooklyn Locals
Learn more about
our newsletter options >>

(888) 890-6222

(718) 522-1071

Call Code:

Have Questions?

Want lower pricing?

Call Us Now.

(Se habla Espanol)

We offer some of the best support in the industry. Talk to real musicians and audio professionals who live and work in Brooklyn, NY.

Secure Shopping

Our website features 128 Bit SSL Encryption

McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams