From Focusrite
The ISA 828 Mk1 incorporates eight of Focusrite's classic mic preamps, with Lundahl LL1538 transformers on every input. Each channel has the option of mic or line inputs, while inputs 1-4 also feature instrument inputs on the front panel. Each mic pre has variable input impedance, to provide a range of subtly different sonic options when using microphones, including an 'ISA 110' setting, which replicates the impedance of the original Focusrite mic pre.
Up to 60dB of gain is available, with a further +20dB of continuously variable trim, providing a huge 80dB gain range. The high-pass filter has a fixed 75Hz frequency and 18dB / octave roll-off for minimising rumble, stand-borne noise and other low-frequency sounds. The ISA 828 MkII also features per-channel, six-segment LED meters, and switchable rear-panel insert points, which allow the use of inline processors such as compressors or EQs.
Dedicated connectors for mic and line-level inputs allow all sources to be connected simultaneously, making ISA 828 Mk1 perfect for permanent installation in a rack.
Features:
- Classic ISA mic preamp design featuring Lundahl LL1538 input transformer
- Front-panel instrument inputs to first four channels
- Line inputs with dedicated input connectors and front-panel select switch
- Switchable input impedance including classic ISA 110 setting
- High-pass filter with fixed 75Hz frequency and 18dB/octave roll-off
- Switchable insert points when used with A-D card
- Per-channel six-segment LED peak-level meters
MIC INPUTS
Gain Range
0dB to +30dB (30-60 switch disabled) and +30dB to +60dB (30-60 switch enabled) in 10dB steps, with an additional +20dB of continuous trim
Input Impedance
Low = 600Ω, ISA 110 = 1400Ω, Med (Medium) = 2400Ω, High = 6800Ω
Max. Input Level
+7dBu, min gain, medium Z
Frequency Response (20Hz - 20kHz)
20Hz - 20kHz ±0.2dB, min gain, medium Z
THD + N
91dB (0.0028%) @ -1dBr, min gain, medium Z
EIN
123dBu 'A'-Weighted (typical)
Signal-To-Noise Ratio
122dB 'A'-Weighted (typical), medium Z
Common-Mode Rejection Ratio
- 997Hz CMRR
- -93dB, min gain, medium Z
Phantom Power
+48V, independently switchable per channel
High-Pass Filter
75Hz knee frequency, 18dB/Octave, independently switchable per channel
Phase
Inverts the phases of the selected input
Frequency Response (10Hz - 110kHz)
10Hz - 110kHz ±1.5dB, min gain, medium Z
WEIGHT AND DIMENSIONS
Weight (Without Accessories)
7.05kg / 15.55lbs
Weight (With Accessories)
7.48kg / 16.49lbs
Height
88mm / 3.46"
Width
482mm / 18.98"
Depth
325mm / 12.80"
LINE INPUTS
Gain Range
20dB to +10dB in 10dB steps, with an additional +20dB of continuous trim
Input Impedance
Low = 600Ω, ISA 110 = 1400Ω, Med (Medium) = 2400Ω, High = 6800Ω
Max. Input Level
+25dBu, min gain, low Z
Frequency Response (20Hz - 20kHz)
20Hz - 20kHz ±0.1dB, min gain, low Z
THD + N
91dB (0.0028%) @ -1dBr, min gain, low Z
Signal-To-Noise Ratio
122dB 'A'-Weighted (typical), min gain, low Z
Frequency Response (10Hz - 122kHz)
10Hz - 122kHz ±3dB, min gain, low Z
INSTRUMENT INPUTS
Gain Range
+10dB to +40dB with continuous gain using trim pot
CROSSTALK
Microphone Talkback
60dB; 20Hz - 20kHz, min gain, medium Z
LINE CROSSTALK
Microphone Talkback
80dB; 20Hz - 20kHz, min gain, medium Z
INSTRUMENT CROSSTALK
Microphone Talkback
80dB; 20Hz - 20kHz, min gain, medium Z
FRONT PANEL CONNECTIVITY
- Channel Count
- 2 Channels In
Instrument Inputs
4 x 1/4" jack inputs
Instrument Inputs
4 x 1/4" jack inputs
REAR PANEL CONNECTIVITY
Mic Inputs
- Input
- 8 x Female XLR
LINE LEVEL
Channel Count
8 In and 8 Out
Input
8 x 1/4" jack inputs
Output
1 x DB-25 connectors (AES59)
INSERTS
Channel Count
8 In
Input
1 x DB-25 connectors (AES59)
PSU
PSU
1 x IEC Input
REAR PANEL INDICATORS
Control Functions
1 x Pot (Meter Trim)
HEAT PERFORMANCE
Operating Temperature
Operates at up to an ambient temperature of 40 degrees Celsius
FRONT PANEL INDICATORS
Control Functions
16 x Pots (Gain and Trim). 60 Switches (On/Off Switch, 30-60 Gain, +48V, Phase, HPF, Insert, Z In, Input, Meters Pre A-D, Clock Select and Ext. Word Clock)
Warranty
This item is sold without the Sound Pure 3-year warranty (used / B-stock / dealer-exempt). Coverage terms for items in this category live in Terms & Conditions, Section 27.
Returns
Try Before You Buy: take it home, commit only when it's right. Program details →
Sound Pure Studios · Durham, NC
Come hear it in our control rooms.
Sound Pure is a working studio in Durham, NC — a 1,000 sq ft live room and two pro control rooms. Book a session to audition gear in a world-class acoustic space before you buy.