Focusrite ISA One Classic Analogue Microphone Pre-amplifier

£449.00 £464.00
Save:  £15.00 (3%)
Earn 449 Loyalty Points.



In stock, immediate despatch

Order soonfor delivery on using our express service
Need advice? Give us a call01274 394 730

Questions about this product?

Get in touch. Our experts are ready to help with anything you need to know!

Seen a better price elsewhere?

Let us know and we’ll do our best to match it. Buy safe through an official Authorised UK Dealer.

spread the cost with finance

Apply for finance on eligible products by clicking the Duologi button, or call us to discuss the options.

Price Match

If you have seen a better price but would rather buy from a trusted UK based authorised dealer, then please get in touch and we will do our best to match or beat any genuine price quote.

The following rules apply

  1. The dealer must be a UK mainland authorised dealer of the brand in question
  2. The item/s must be brand new, In stock and available for next day delivery
  3. Items cannot be part of a sale

We only match UK based authorised dealers, for that reason we cannot match the following companies

Thomann (Germany)
Music Store / DV24/7 (Germany)
Bax-Shop (Netherlands)
Kytary (Czech Republic)

  • ISA series transformer-based preamplifier
  • Headphone output with volume control
  • Dedicated insert point
  • Optional stereo 192kHz A-D converter
  • Backlit VU meter with variable calibration
Warranty:  3 Years
  • Unrivalled Advice

    Our experts are ready to help. See our feedback:

    Trust Pilot
  • Free Delivery

    Free UK saver delivery on all our products.
    More info

  • No Fuss Returns

    Refund or exchange within 30 days. More info

Secured by Thawte

Classic Focusrite Microphone Pre Amp

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 thousands 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

  • 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
  • Backlit VU meter with variable calibration
Analogue Channel Inputs XLR Mic input
One XLR and one TRS line input
XLR Instrument input TRS Jack
External ADC input TRS Jack
TRS jack return
Analogue Channel Outputs TRS jack send
XLR balanced line output
XLR DI output
TS jack DI through
Analogue Channel Additional I/O TRS Jack cue mix left input
TRS Jack cue mix right input
1/4” TRS Jack headphones output
Mic Input Response Gain range - 0dB to 60dB in 10dB steps + 20 dB of variable gain
Input Impedance - Switched Impedance setting Equivalent Input Impedance at 1kHzLow = 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 - Noise at output with unity gain (0 dB) and 22 Hz-22 kHz band pass filter-97 dBu
Signal-to-Noise Ratio - 106 dB relative to max headroom (9dBu)
Total Harmonic Distortion + Noise - Measured at medium gain (30dB) with a 1kHz -20dBu input signal and with a 22Hz/22kHz band-pass filter< 0.0009%
Frequency Response - At minimum gain (0 dB)-0.5dB down at 10Hz and -3dB down at 125kHz
 At maximum gain (60dB) -3dB down at 16Hz and -3dB down 118kHz
CMRR (Common Mode Rejection Ratio) 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 - 10 kΩ from 10 Hz to 200 kHz
Noise - Noise at main output with gain at unity (0 dB) measured with 50 Ω source impedance and a 22Hz - 22 kHz band pass filter -96 dBu
Signal-to-Noise Ratio - Measured with a 22 Hz-22 kHz band pass filter120 dB relative to max headroom (24 dBu)
118dB relative to 0dBFS (+22dBu)
Total Harmonic Distortion + Noise - Measured with a 0 dBu input signal, and a 22 Hz-22 kHz band pass filter0.0001%
Frequency Response - At unity gain (0 dB)-0.3dB down at 10Hz and -3dB down at 200kHz
Instrument Input Response Gain range - 10dB to 40dB continuously variable
Input Impedance - High = greater than 1M
Low = greater than 300k
Noise - Measured with 22 Hz-22 kHz band pass filterMinimum gain (+10 dB): -92 dBu
Maximum gain (+40dB): -62dBu
THD - At minimum gain (+10)
Frequency Response - At minimum gain (+10 dB)-10dB input: 10Hz-100kHz +/- 0.6dB
At maximum gain (+40 dB)-40dB input: -2.5dB down at 10Hz and 0dB at 100kHz
Meters Moving Coil (MC) Meterfactory 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 MetersCalibrated 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 LevelsAs 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
Frequency ResponseAt minimum gain (+10 dB)-10dB input: 10Hz-100kHz +/- 0.6dB
At maximum gain (+40 dB)-40dB input: -2.5dB down at 10Hz and 0dB at 100kHz
High-Pass Filter Roll-Off18 dB per octave (3 pole filter)
FrequencyFixed 75Hz measured at the 3dB down point
Weight and Dimensions W x D x H 220mm (W) x 104mm (H) x 254 - 290mm (D - top to bottom)8.66" (W) x 4.1" (H) x 10" - 11.4" (D - top to bottom)
Weight - 3.9 kg 8.6 lbs

UK Deliveries

We offer free delivery on all of our items (UK mainland only) please see details below.

Destination Delivery Times Cost
UK Mainland Economy (only available for orders over £70) 3-5 Working Days* Free of charge
UK Mainland Express Next Day* £4.99
UK Mainland Saturday and Sunday Saturday or Sunday £14.99
Northern Ireland, Scottish Highlands 2 Working Days* £11.99
Scottish Islands, Channel Islands, Isle of Man, Isles of Scilly 2 Working Days* £14.99

*Applies to in stock items. Orders placed after 5pm will be dispatched the following working day, next day delivery does not include Saturday or Sundays. Some services are only available to UK mainland addresses.

Jersey and Guernsey are also VAT exempt, so 20% will automatically be knocked off when selecting your country in the basket or checkout.

Pre 10am, 12am and named day delivery options are available in the basket, simply enter your postcode for an accurate price. Please note there is a surcharge for individual, very heavy items over 30kg. This will be applied in the basket.

European Deliveries

We ship to most European destinations, simply choose your country and the correct price will show up in the basket.

Delivery times range from 2-4 days, 4-9 for remote areas.

A quick glance at some of our rates...

Destination Delivery Times Cost
Republic of Ireland, Belgium, France, Germany, Italy & Netherlands 2-4 Working Days £14.99
Spain, Austria, Denmark, Hungary 3-5 Working Days £19.99

Rest of the World

We can ship anywhere in the world, if you are outside of the EU we will knock 20% VAT off the price, rates depend on weight so please get in touch for an accurate price,

Read more about our delivery here.


Our returns system is easy, you have the right to cancel an order up to 14 days, please check our full returns policy here.

Be the first to Write a Review for this item!

Focusrite ISA One Classic Analogue Microphone Pre-amplifier


Price Match

If you have seen one of our products cheaper elsewhere, let us know! We will check it out and either match or beat the price. Simply fill in the following form and click 'Submit' to send it to our staff.

Expert advice free of charge 01274 394 730 Mon - Fri: 9.30am - 6pm / Saturday 10am - 5pm