Item # 104907076 | Customer Ratings: ( 5 Based on 8 reviews)

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Focusrite ISA One Classic Single Channel Mic Pre
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Classic vintage microphone preamplifier at a groundbreaking price.

Back in the mid-1980s, Sir George Martin commissioned console design legend Rupert Neve to build a series of new, ‘no compromise’ console modules for AIR studios. They were an enormous hit and formed the basis of the Focusrite Studio Console, widely regarded as the best-sounding analogue recording console of all time. Today, the descendants of those modules are used in leading studios around the world, and their sought-after Focusrite Heritage Sound lies behind hundreds of hit records. Today’s ISA Range from Focusrite puts the classic sound of Focusrite into your own studio or live performance.

Featuring a rugged, portable all-metal enclosure, the ISA One combines the classic Focusrite microphone preamp with a flexible, independent DI channel and optional 192kHz precision A/D conversion.

At the heart of the ISA range is the microphone preamplifier with its Lundahl input transformer – essentially the same circuit, based on the original ISA110, that has been used for 30 years in successive Focusrite designs. The input transformer imparts a special character to the sound that can’t be truly emulated in any other way: inseparable from the microphone itself, the transformer input stage is ideal for use with classic microphones. But this mic pre has a twist the original didn’t have, which makes it far more versatile: four carefully-selected impedances allow you to match microphone to input in different ways. Bring out the character of a classic mic or emphasise a special feature, or go for a totally transparent, modern sound – it’s up to you.

Whether you’re an artist, engineer or producer, you’ll appreciate the versatility of the ISA One, with its front-panel DI input. The DI includes low/high impedance switching and an amplifier output, and its own feed to the optional A/D converter and separate rear-panel XLR output.

Focusrite ISA One Classic Single Channel Mic Pre Features:

  • ISA Series Transformer-based Preamplifier
    Flexible Independent DI Channel
    Switchable Impedance
    Headphone Output with Volume Control
    Dedicated Insert Point
    Optional stereo 192kHz A-D converter
    Lundahl LL1538 Input Transformer

Focusrite ISA One Classic Single Channel Mic Pre Specifications:

  • 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

    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


    Analog 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

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

    Analog Channel Additional I/O:
    Cue mix left input: TRS Jack x 1
    Cue mix right input: TRS Jack x 1
    Headphones output: ¼" TRS Jack x 1

    8.6 Ib. (3.9 kg)

    Dimensions(H x W x D)
    8.66" x 4.1" x 10" - 11.4", (220mm x 104mm x 254 - 290mm)

    Related Products
    ISA Stereo ADC (compatible with ISA 430 MKII and ISA One)ISA Stereo ADC (compatible with ISA 430 MKII and ISA One)

Focusrite ISA One Classic Single Channel Mic Pre

All Focusrite products are built to the highest standards and should provide reliable performance for many years, subject to reasonable care, use, transportation and storage.

In the event of a Manufacturing Defect becoming evident within 12 months from date of purchase Focusrite undertakes that the product will be repaired or replaced free of charge if the product is returned to the authorised dealer from whom it was purchased. In these circumstances, or if you need an out-of-warranty repair to your Focusrite product, please contact your local Focusrite distributor in your country of residence or business : Find your local distributor here and you will be advised of the correct return procedure.

Alternatively contact the Focusrite Reseller from which you purchased the product. If you purchase a Focusrite product outside your country of residence or business you will not be entitled to ask your local Focusrite Distributor to honour this Limited Warranty, although you may request a chargeable repair.

Alternatively, the unit may be returned at your cost to the dealer you purchased the unit from so that they can organise a Warranty repair with their Focusrite Distributor.

This Warranty does not include cost of shipping to and from the authorised dealer from whom it was purchased. In every case it will be necessary to provide the original invoice or store receipt to accompany the defective product to the supplying dealer. This Limited Warranty is offered solely to the first purchaser of the product from an Authorised Focusrite Reseller (defined as a reseller which has purchased the Product directly from Focusrite Audio Engineering Ltd. in the UK or its Authorised Distributors outside the U.K,) and is not transferable.

This Warranty is in addition to your Statutory Rights in the country of purchase.

Please note: A Manufacturing Defect is defined as a defect in the performance of the product which may be expected from a reasonable interpretation of the published description and performance specifications as published by Focusrite Audio Engineering Ltd. This does not include damage caused by post-purchase transportation, storage or careless handling, nor damage caused by misuse.

A significant proportion of products returned under Warranty (which are very few in number compared to numbers sold) are found not to exhibit any fault at all. Please check that the mains voltage is correctly set for your local supply and that your connecting cables are in good order and correctly connected.

If in doubt about the product functions please read the user guide and if necessary contact your dealer for advice before returning the product to the supplying dealer. You can also contact the Focusrite Tech Support team at the Focusrite Answerbase for general advice.

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Pro Coverage includes:

  • Accidental damage protection (new gear only)
  • Expedited Repair
  • Free Shipping (for returns or repairs)
  • 100% Coverage for Commercial Use
  • Extended Return Period
  • Extended Price Protection
  • No Lemon Guarantee
  • Free Transfer of Coverage to a new owner
  • Repair Costs Covered for up to 3 years from date of purchase
  • Repairs Can Be Authorized Toll-Free by Phone or the via the web
Product Reviews
(Based on 8 reviews)
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  • Transparent with a hint of...

    As reviewed by Vivid Studio on 10/4/2009

    This thing is great, just gotta throw that out. It has a character you can't mistake. Because of the lundhall transformers, you get this sort of sizzle that you have to hear to understand. When ABed with some less expensive preamps you will notice the effects immediately. I also enjoy the fact that you can use it as a latency free piece. During a session, the singer was having trouble singing through pro tools and my latency. I didn't want to sacrafice plug's to improve latency, so we ran it through the ISA. This really is the centerpiece of my pro tools rig. I find myself running everything through it. I would say it is a great value that can stand up to all the other big name pre's.

    18 of 18 people found this review helpful.
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  • A "No-Brainer"! A Great Preamp and A Great FIRST Preamp

    As reviewed by Bob Gallagher on 4/7/2011

    I ordered the Focusrite ISA One and the Universal Audio Solo 610 so I would have one very nice Solid State transformer based Preamp and one very nice Tube Preamp in my home studio. In my opinion, this is "the preamp" everybody should save up for and buy as a first preamp as opposed to buying a couple of lower priced preamps before buying a "good" preamp. For less than the price of an ART MPA II and a Focusrite Trakmaster Pro, the ISA One gives you a multi-faceted, "multi-color" preamp that you'll most likely keep for a long time. I love how my Solid State and Tube Condensor microphones sound going through this thing, especially at the ISA 110 setting. That setting, its Swiss Army Knife capabilities and its incredible price make purchasing this unit a "No-Brainer". PS-I have owned the ISA One for 3 months. It is built like a tank. The look and feel is fantastic for what that might be worth. More importantly, though, I think it sounds great!

    2 of 2 people found this review helpful.
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    As reviewed by Mark Westphal on 1/21/2014

    What a great pre-amp! I've been dealing with a lot of cheap ones that sound ok, but when I connected this ISA ONE to my Shure SM7b, it was like the clouds rolled away, and all was great. Absolutely no noise, and this holds true for all of my mic locker...condensers, ribbons, etc. I can't recommend this enough, and talk with your Guitar Center pro audio guy, and he will probably give you a nice break on the price. got it right.

    1 of 1 people found this review helpful.
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Westlake Village, CA 91359
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