The ISA428 MkII provides four of Focusrite's prestigious transformer-based microphone preamps. It features the same classic circuitry and renowned audio quality found in the original at a new level of affordability. With selectable input impedance, direct instrument inputs and an optional eight channels of high-quality analogue to digital conversion, the ISA428 MkII creates the perfect front end for the discerning recording professional.

First introduced in 1985, the ISA microphone preamp holds a reputation for outstanding transparency along with subtle warmth contributed by transformer core saturation. The addition of a variable impedance circuit allows ISA users to perfectly match the preamp with any microphone, or to use different settings creatively to shape the sound of the microphone. Unchanged for decades, the ISA microphone preamp topology offers incredible clarity and the signature Focusrite sound that makes it the top choice among many audio professionals today.

The optional class-leading eight-channel A-D converter option used with the ISA828 is also compatible with the ISA428 MkII. Along with the four mic preamp inputs, four additional inputs allow you to route other line signals through the converter. High quality Burr-Brown Pro Audio Amplifiers and flagship PCM4220 A-D converter chips seated within Focusrite custom analogue circuitry deliver unparalleled performance. Specifications include a dynamic range of 122dB and jitter performance below 250 picoseconds. The card can be retrofitted at any time. Thanks to its convenient 25-pin D-Type connector, it integrates seamlessly with most digital workstations, including Pro Tools.

MPN: ISA428MkII
UPC: 815301005018

• Four ISA series transformer-based preamps

  ISA series mic preamps have been the producers' choice on countless hit records over the last two decades.
  
• Eight-channel optional A-D converter 
Four additional A-D converter inputs allow eight channels of high-quality conversion, with a dynamic range of 122dB and jitter performance below 250 picoseconds. More information can be found here.
  
• Selectable impedance Ideal for mic matching or extended microphone creativity. Settings include the ‘Vintage ISA110' setting, providing the original Focusrite signature sound.

  
• Four front panel instrument inputs
 Instant access on the front fascia - no separate DI box required.
  
• Dedicated analogue insert points Switchable insert points are featured on every channel, allowing routing (between pre-amp and output) through additional external processing.
  
• Variable high pass Focusrite filter
 Provided on every channel, this is the same filter as featured on the original ISA428.
  
• 
Accurate LED meters for every channel

  Clear metering designed to catch even the fastest and most elusive of transients.

  
• Phantom power available on every channel
  
• Trim control allows 20dB of extra gain with fine adjustment
  
• Phase reverse buttons help to correct phase issues with microphones or cables
  
• Optional A-D converters easily synchronise to external word clock