Focusrite ISA828MKII 8 Channel Pre Pack Preamp
Description
More mic inputs for less
You can enjoy the benefits of Focusrite’s classic heritage sound in many ways, but one of the most cost-effective is with the ISA 828, which includes eight Focusrite transformer-based mic preamps in a compact 2U package, along with front panel instrument ins and rear panel line inputs.
The Focusrite ISA mic preamp is based closely on the original design created by Rupert Neve in 1985 for Sir George Martin’s AIR Studios. Virtually unchanged over the years, the ISA mic preamp delivers the warm, full sound that could be just what you’re looking for – and if you use a significant number of microphones at once, the ISA828 is for you.
Additional mic versatility
We just made one significant change to the design, and that was to add three additional input impedances to the original vintage ISA110 setting. Ranging from low to high impedance, the four settings enable you to get the very best sound from a vintage mic – it’s after all what the ISA was originally designed for – but also get a clean, transparent sound from the microphones of today. Or you can enhance a particular feature of your favourite microphones. Indeed, ISA makes the perfect match for any mic. There’s also a vintage design 75Hz / 18dB per octave high pass filter on each channel for detailed control of the bass end.
The ins and the outs
Four front-panel direct instrument inputs are also provided, with high and low impedance settings for extra versatility, and the input side is rounded out by eight TRS rear-panel line inputs. With convenient 25-pin D-type output connectors, ISA 828 is easy to interface with Avid Pro Tools | HD™ and other popular recording systems and consoles. There’s also an optional 8-channel A/D converter available with 122dB dynamic range and sampling up to 192kHz. An insert is available on each channel between the preamp and the A-D. 6-LED meters let you know exactly what is going on, and use the same reference points as Pro Tools | HD.
Specifications
Mic Inputs
| Gain range | 0 dB to 60 dB in 10 dB steps |
| Input Impedance | Variable, 600Ω, 1k4Ω, 2k4Ω, 6k8Ω |
| EIN (equivalent input noise) | -126 dB measured at 60 dB of gain with 150 Ohm terminating impedance and 22 Hz / 22 kHz bandpass filter |
| Noise at main output with gain at unity (0 dB) | -97 dBu measured with a 22 Hz / 22 kHz bandpass filter |
| Signal to noise ratio relative to max headroom (9dBu) | 106 dB |
| THD at medium gain (30dB) | 0.0008% measured with a 1 kHz -20 dBu input signal and with a 22 Hz / 22 kHz bandpass filter |
| Frequency response at minimum gain (0 dB) | -0.5 dB down at 10 Hz and –3 dB down at 110kHz |
| Frequency response at maximum gain (60 dB) | –3 dB down at 16 Hz and –3 dB down 85 kHz |
| CMRR | 91.8 dB (Channel 1, 1 kHz, maxiumum gain) |
| Crosstalk Channel to Channel | With 10 dB @ 1 kHz input to chA, chB output = 102 dBrA. With 10 dB @ 10 kHz input to chA, chB output = 84 dBrA |
Line Inputs
| Gain range | -20 dB to +10 dB in 10 dB steps |
| Input Impedance | 10 kΩ from 10 Hz to 200 kHz |
| Noise at main output with gain at unity (0 dB) | -96 dBu measured with a 22 Hz / 22 kHz bandpass filter |
| Signal to noise ratio relative to max headroom (24 dBu) | 120 dB |
| Signal to noise ratio relative to 0dBFS(+22dBu) | 118dB |
| THD at unity gain (0dB) | 0.001% measured with a 0 dBu input signal and with a 22 Hz / 22 kHz bandpass filter |
| Frequency Response at unity gain (0dB) | 0.3 dB down at 10 Hz and –3 dB down at 122 kHz |
Instrument Inputs
| Gain range | 10 dB to 40 dB continuously variable |
| Input Impedance | 1 MΩ or 300 kΩ |
| Noise at minimum gain (+10 dB) | -90 dBu measured with a 22 Hz / 22 kHz bandpass filter |
| Noise at maximum gain (+40 dB) | -62 dBu measured with a 22 Hz / 22 kHz bandpass filter |
| THD at minimum gain (+10 dB) | 0.002% measured with a 10 dBu input signal and with a 22 Hz / 22 kHz bandpass filter |
| Frequency Response at 10 dB gain with -10 dB input | 10 Hz - 200 kHz +/- 0.6 dB |
| Frequency Response at 40 dB gain with -40 dB input | -2.5 dB down at 10 Hz and 0 dB at 200 kHz |
Instrument Inputs
| Roll off | 18 dB per octave 3 pole filter |
| Frequency | Fixed 75Hz measured at the 3dB down point |
Weight and Dimensions
| Weight | 8.84 kg | 19.5 lbs |
| Dimensions (W x H x D) | 484mm (W) x 85mm (H) x 305mm (D) (350mm depth with heat sink) | 19" (W) x 3.5" (H) x 12" (D) (13.8" depth with heat sink) |
