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Ultimate Mic Preamps For Recording Studios (Over $1,000)

by | Mic Preamps | 2 comments

There’s a reason that pro studios have expensive high-quality mics, mic preamps, compressors, EQs and other gear.

Great sound starts with the best quality recording equipment!

People sometimes ask, “Is it really worth spending $1,500 on a mic pre?  Does it really sound that much better than a $500 mic pre?”

Think of these top mic preamps like having a first-class airline ticket to anywhere you want to go.

Sure, you can travel from A to B in basic economy coach… but it sure isn’t going to be a wonderful or memorable experience…

First-class gives you luxury with attention to detail and personalized service.

Coach just gets you there…

With a top-quality mic pre, you get premium experience and premium sound

… and you can use it as many times as you want, unlike a plane ticket!

Ok, enough of this metaphor…

This article on ultimate microphone preamps (over $1,000) is the fourth in a series on the best mic preamps available today.

Previous articles covered lower-priced mic preamps – below are the links to those articles:

The over $1,000 price class opens the door to world-class mic preamps that provide premium features, top-notch construction, and of course, the best possible sound quality.

The reviews are divided into two sections:

  • Best Single-Channel Mic Preamps
  • Best Multi-Channel Mic Preamps

Under each section, I review the best mic preamps in these category types:

  • Solid-state
  • Tube
  • Hybrid solid-state/tube

NOTE: If I could not find any mic preamps under a category that fit my review criteria, then there’s no review.

Ultimate Single-Channel Mic Preamps Over $1,000

Channel Strip:

Avalon VT-737SP
Daking Mic Pre Equalizer

Ultimate Multi-Channel Mic Preamps Over $1,000


Millennia HV-3C
Neve Portico 5012
API 3124+
SSL Alpha VHD-Pre
Grace Designs M201
Focusrite ISA428

Hybrid Solid-State/Tube:

Universal Audio 4-710d

500 Series Mic Preamps

If you are interested in 500 series mic preamps, please see these review articles:

Ultimate Guide To Choosing The Best Microphone Preamp For Your Home Studio

Also check out my Ultimate Guide To Choosing The Best Microphone Preamp For Your Home Studio.  You’ll learn how mic preamps work, the types of preamps available, and how to choose a mic preamp that best fits your intended uses and, of course, your budget.

Single-Channel Mic Preamps:

Channel Strip Mic Preamps

Ultimate Mic Preamps Over $1,000 - Avalon VT-737SP

Avalon mic preamps are celebrated for the remarkable depth and warmth they add to recordings.

The VT-737SP is Avalon’s flagship mic pre that was the winner of the 1999 EM Editors Choice Award for Best Preamp and the 2015 Readers Choice Award for Best Outboard Gear.

It’s an all-tube channel strip that combines a tube mic pre with an opto-compressor and a 4-band sweepable EQ in a double space 2U full rack enclosure.

It features Class A circuitry for the best possible sound quality.

I bought my VT-737SP in 2005, and it has been an incredible investment that had more than paid for itself over the years.

It has powered many of my vocal sessions, acoustic guitar tracks, guitar overdubs, drum and percussion recordings, and more over the years for commercials, film scores, trailers, records, and production library work.

It’s built like a tank – it weights over 22 lbs. – and I remember struggling to get it mounted my rack when I bought it.

It has never left my studio since…


Sometimes a picture ( or video) is worth a thousand words.  The following video will walk you through the basic features:

Avalon VT-737SP Overview

Mic Preamp

The Class A preamplifier utilizes dual triode vacuum tubes (Sovtek 6922) configured with minimum negative feedback.

You can connect to the mic pre in three ways:

  • Through the rear panel balanced XLR mic input
  • Through the rear panel balanced XLR Line input
  • Through the front panel Instrument hi-Z input jack

A front panel switch lets you choose the input source.

A variable high-pass filter (30Hz to 140Hz), gain boost, and phase-reverse options are available on all three inputs.

48V phantom power is available on the mic input only.

There’s plenty of gain (up to 58dB for the mic input) and headroom (+30dB) to get the best results from any microphone, and a large analog VU shows the signal level.

After the input stage, the signal goes to the two signal processing stages: the opto-compressor and the EQ.


The opto-compressor offers full dynamic control from soft compression to hard- knee limiting.  It includes the standard threshold, ratio, attack and release controls for maximum flexibility.

Engaging the Meter button changes the VU meter to show gain reduction instead of input gain.

The EQ to Comp switch chooses if the EQ will be pre (before) or post (after) the compressor for flexible tone shaping.

4-Band Sweepable EQ

The VT-737SP has Bass, Low-Mid, High-Mid and Treble EQ bands.

Each band has a separate frequency selector controls and boost/cut pots to tailor the sound to your liking.

Bass and Treble bands are shelf EQs (low-pass and high-pass filters), while the dual mid bands include variable frequency and a switchable Q-bandwidth.

For added flexibility, engaging the Frequency buttons changes the frequency range X10 (for example, 150Hz becomes 1.5kHz)

Finally, pushing the side-chain to mids button allows the compressor’s performance to react to the mid-EQ settings. This is very handy for reducing sibilance on vocals.

How Does It Sound?

I love my VT-737SP.

Paired with my Neumann U-87 or Neumann TLM-103, it delivers stellar vocal and acoustic guitar tracks, which is what I mostly record.

Most reviewers agree that the VT-737SP adds lots of warmth, intimacy, and depth to recordings.

It gives tracks that smooth, silky, warm pro sound you want to hear but don’t with lesser-quality mic preamps.

Below is a video demo of the VT-373SP in action:

Avalon VT 737SP Preamp – Acoustic Guitar Test

This link leads to a video demo of a male vocal:

Avalon 737sp Review w/ Audio

Final Thoughts

The VT-737SP is an amazing-sounding channel strip that will give your tracks that smooth, luxurious sound you’ve always wanted.

Because it has tons of features, it does take some time to find the best settings for recording vocals and various instruments.  Thankfully, the user manual does include some sample settings for recording vocals and some popular instruments.

The VT-737Sp is not cheap, but if you want to move your tracks to the next level, it will definitely help you create the best sounding recordings you can.

FYI, two VT-737SPs can be linked via a rear panel link cable for stereo tracking.  That’s a very serious stereo signal chain!

Highly recommended!

Avalon VT-737SP

Check Price:
Amazon | Guitar Center


  • Single-channel tube channel strip with mic pre, opto-compressor, and sweep EQ
  • Discrete high-voltage Class A circuitry
  • Uses 4 dual triode vacuum tubes (Sovtek 6922)
  • Hi-impedance instrument input/ DI input
  • -92dB low noise design
  • Analog LED metering
  • Balanced XLR and ¼” TRS, and instrument inputs | balanced TRS output.
  • 48V phantom power
  • High-pass filter
  • Polarity reverse switch
  • 2U double space 19” rack enclosure
Ultimate Mic Preamps Over $1,000 - Daking Mic Pre Equalizer

Daking is a boutique maker of pro audio equipment based in Las Vegas, NV.

Since 1993, they have been committed to making top-quality mic preamps with the best designs and components like discrete circuitry and Class A amplifiers.

For the Mic Pre Equalizer, Geoffrey Daking’s goal was to create a mic pre that combined the best of classic American and British mic preamps with modern construction and reliability.

From tons of positive reviews and user testimonials, it looks like Daking achieved his goal in creating a modern day classic that delivers outstanding audio quality.

Overview & Features

The Daking Mic Pre Equalizer is a single-channel, 1U rack-mountable, solid-state channel strip featuring Daking’s acclaimed mic pre with a world-class EQ.

It’s a discrete Class A transformer balanced (input and output) unit with top-notch components and construction.

The unit is divided into two sections: the mic pre and the EQ.

Founder Geoff Daking explains his Mic Pre EQ in the video below:

Daking Mic Pre Equalizer Explained

Mic Pre

The mic pre has mic and line inputs and outputs, and buttons for mic/line selection, 48V phantom power, a 20dB pad, and polarity invert.

The mic pre has 70dB of gain which is more than enough to handle even the lowest output ribbon or dynamic mics.

EQ Section

The EQ section features 4 individual EQ bands with 5 stepped frequencies per band. Each band has a continuously variable EQ boost or cut of 15dB.

A high-pass filter helps remove extra high-frequency energy, while a low-pass filter helps remove low-end rumble.

How Does It Sound?

The Mic Pre Equalizer delivers clean, vibrant, professional sounding tracks – exactly what you would expect in a mic pre at this price point.

Whether recording vocals or instruments, the circuitry enhances the natural sound source in a very musical way.  It doesn’t add much color to a track but rather just makes it sound great with beautiful detail and clarity.

Audio Examples

You can hear demos on guitars, bass, vocals, and more at the site below.  Just click on Preamps and then choose the Daking Mic Pre Equalizer:

ZenPro Audio Clipalator

NOTE: You can also download all files as high-quality 320K mp3s for comparison against other mic preamps.

The following link has multiple audio examples of the Mic Pre EQ in action.  Scroll about 1/3 down the page to find the audio files.

Transaudio Group Audio Files

Final Thoughts

The Daking Mic Pre Equalizer is a powerful addition to any studio.  The pristine sound quality and flexible EQ let you shape and hone your tracks to sound their very best.  It should be at the top of your list!

Daking Mic Pre Equalizer

Check Price:


  • Single-channel solid-state channel strip with mic pre and EQ
  • Discrete transistor circuitry and Class A amplifiers
  • 4-band EQ with hard bypass
  • Hi-impedance instrument input/ DI input
  • -92dB low noise design
  • Balanced XLR and ¼” TRS, and instrument inputs | balanced TRS output.
  • 48V phantom power
  • 20dB mic input pad
  • Polarity reverse switch
  • Single space 19” rack enclosure

Best Multi-Channel Mic Preamps:

Solid-State Mic Preamps

Ultimate Mic Preamps Over $1,000 - Millennia HV-3C

Millennia is known for their audiophile mic preamps that have been used in critical recording sessions for over 25 years.

They are the recipient of more than 30 awards and have more than 40,000 channels in use with clients all over the world.

In fact, Millennia has posted on their website a very impressive list of orchestras, recording studios, scoring stages, post houses, artists, and more that use Millennia’s products.

The Millennia HV-3C is a single rack space, two-channel solid-state mic pre that provides unparalleled uncolored sound.

It has an unprecedented frequency response of 3Hz to 300Hz!

The HV-3C is designed with ultra-premium grade components for one thing only: to deliver the best crystal-clear transparent sound possible with wide dynamic range and lots of headroom.


The front panel controls are very simple:  each channel has just a high-resolution input gain control, a signal indicator LED, a 48V phantom power button, and a switch to choose mic or line input.

An optional high voltage (130V) switch selects the rear panel high-voltage (130V) XLR connectors for use only with certain B&K audiophile microphones.

The rear panel has balanced XLR mic input jacks, and balanced XLR line level mic output jacks.

There are also two high-voltage (130V) XLR connectors for use only with certain B&K audiophile microphones.

How Does It Sound?

The HV-3C delivers uncompromising audio for the most transparent audiophile-level sound available.

Below are some pro audio reviews of the HV-3C:

“My jaws fell open when I first switched to the HV-3 Series stereo mic pre. Its presence and clarity were outstanding. A solo voice sounded extremely immediate, and had an almost palpably “real” quality. The low end was very tight, showed good extension and “slam,” while the high end was detailed in the extreme, without the least amount of harshness…”
Pro Audio Review

“…The HV-3 Series stereo mic pre provided an absolutely faithful rendition of the microphone’s sound, without imparting any coloration of its own… An excellent value offering impeccable audio specs, first-rate construction, and sonic transparency under any conditions. The Millennia Media HV-3 is… for those who seek absolute purity in reproduction.”
MIX Magazine, George Petersen, Editorial Director

“The Millennia HV-3 stereo mic pre sounds best of the units evaluated. We found the HV-3… to be transparent in the extreme. The security of such a large dynamic range, excellent quality, etc. will be hard to beat….”
Studio Sound UK

“The best-sounding piano recording I’ve ever done. The detail and sense of immediacy was phenomenal… the coolest, quietest vocal chain I’ve ever hooked up in my studio. There was no end to the headroom.”
EQ Magazine

“For sonic accuracy, transparency, and realism (i.e. least amount of coloration), the HV-3 leads the pack. This is the unit I’d choose for live stereo recordings of jazz, classical, or any other style of music for which sonic realism is desirable. The precisely stepped gain controls make it a snap to match stereo levels, and the high headroom allows for dynamic surprises… The last word in clean, accurate, transparent audio.”
Electronic Musician Magazine [in-depth blind listening test of numerous mic preamps]

“Over a period of months, I used the HV-3 on all types of sessions, ranging from stereo-miked chamber ensembles to multi-track pop sessions. In all cases, the HV-3 provided an absolutely faithful rendition of the microphone’s sound, without imparting any coloration of its own… An excellent value offering impeccable audio specs, first-rate construction, and sonic transparency under any conditions. The Millennia Media HV-3 is…for those who seek absolute purity in reproduction.”
MIX Magazine, Feature Review By George Petersen, Editor

The following video demonstrates the HV-3C on acoustic guitar:

Recording Acoustic Guitar – Millennia HV-3C

Final Thoughts

This is a serious mic pre for the highest level of sound quality.  This, or course, is reflected in its price. But if you’re looking for the best transparent sound available today, the HV-3C should be at the top of your list.

Millennia HV-3C

Check Price:
Guitar Center


  • Single-channel solid-state mic pre
  • Transformerless design with discrete hi-speed transistor octet
  • Hi-impedance instrument input/ DI input
  • 65dB gain
  • Stepped gain controls
  • Balanced XLR and ¼” TRS, and instrument inputs | balanced TRS output.
  • 48V phantom power
  • Gold switches
  • -15dB pad switch
  • Mogami Neglex OFC audio wiring
  • Polarity reverse switch
  • Single space 19” rack enclosure
Ultimate Mic Preamps Over $1,000 - Neve Portico 5012

Legendary audio engineer and designer Rupert Neve is the man behind the highly revered Neve line of mic preamps, compressors, and mixing consoles.

Neve started working with audio electronics in the 1940s.  His notable early accomplishments include creating the first modern recording console which included moving fader automation.

In the 1970s he designed and developed some of the most widely used recording gear, including the legendary 1073 mic pre which was originally a module in a custom recording console he created.

Neve later started Focusrite, a major player today in pro audio gear.

Today he runs Rupert Neve Designs, his company that continues to produce top-quality pro audio gear for professional and home recordists.

The Neve Portico 5012 is one of 8 mic preamps in the Portico line.  As stated on the site:

Portico modules embody new Rupert-designed transformers, very short audio paths, minimal negative feedback and discrete single-sided transformer-coupled outputs that leave no possibility of crossover distortion. They are built to work together in a variety of configurations – compatible with any existing high-quality transformer-coupled vintage modules, including the genuine range of my original units.

Such modules may be confidently included in the Portico chain with the sure knowledge that the sound of your favorite classic module will not be diminished. That being said, the Portico Range marks a return to a more colored sound without yielding anything to fidelity! Rest assured that it has all of the characteristics that are so sought after in the vintage designs without any of the maintenance nightmares.

The Portico 5012 is a half-rack, dual-channel solid-state mic pre. It delivers the classic Neve sound known for its warmth, fullness, and vintage tone.


On the front panel, each channel has Input and Trim controls, a mute button, and a Buss send button.  The Buss output is intended for use with the Portico Buss Amp/Monitoring modules.

Each channel also has a fully variable high-pass filter, 48V phantom power, and a phase invert button.

The rear panel has balanced XLR inputs and outputs.

How Does It Sound?

I own a Portico 5015, which is basically a single channel 5012 with an added compressor module.

In a nutshell, it just sounds great on just about everything I put through it – vocals, acoustic guitar, percussion, mandolin, and more.

The Portico 5012, like the 5015, gives tracks that “larger than life” sound that distinguishes Neve products.

The coloration it adds is musical and appealing.  The sound is not transparent and not really “tube-like” – it’s in-between, with powerful lows, smooth round mids, and bright, airy highs.

Engaging the Silk feature adds a vintage sound character that increases the unit’s total flexibility.

Quite a few reviewers said that tracks need little EQ in their mixes after being sent through the 5012.   Many commented that they thought it sounded better than a 1073, which is a huge claim to make!

Final Thoughts

The Portico 5012 is high-performance mic pre for anyone who wants to add that magical Neve sound to their recordings.

It sounds great on virtually everything, though for purist classical recordings it might be a little too colored.

The 5012’s main drawback is that it does not have a DI input.   But if you are willing to live without that, you won’t be disappointed by its sound and performance.

Neve Portico 5012

Check Price:
Guitar Center


  • 2-channel solid-state mic pre
  • Very low noise design
  • 66dB of input gain
  • 8-Step LED metering
  • Balanced XLR inputs and outputs.
  • 48V phantom power
  • High-pass filter
  • Polarity reverse switch
  • Single space half- rack enclosure
Ultimate Mic Preamps Over $1,000 - API 3124+ Mic Pre

API is a leader in the professional audio community, with a legacy of having played a significant role in the development of recorded music since the 1960s.

API products are found in thousands of recording studios and broadcast studios worldwide, and the famed “API Analog Sound” has been a part of many hit records over the last 50 years.

API continues that heritage of premium quality products with the 3124+ mic pre.

It’s a single rack space, 4-channel mic/line preamp that delivers the API sound that is coveted by both pro and home studio owners around the world.


The 3124+ features the same premium RE-115 K mic input transformer and the proprietary output transformer found in all API mic preamps.

On the front panel, each channel has a Gain control, plus polarity, 48K phantom power, -20dB pad, and mic/line switches.

Each channel also has a front panel ¼” high-impedance line input.

On the rear panel, each channel has balanced XLR mic inputs and outputs, and an Insert jack.  There are also ¼” jacks for an Aux Send/Return and two ¼” Stereo left/right jacks.

How Does It Sound?

The 3124+ is an outstanding performer on just about every sound source, but many users feel it really excels on electric guitars, drums, and percussion.  It’s able to handle instruments with hard transients well while making them sound larger than life.

That said, many a vocal track on hit records was sent through an API mic pre…

Driving the mic pre hard really brings out the vaunted “API sound” by accentuating the harmonic saturation, especially in the mid-range.

The following video showcases the 3124+ on a drum kit.  The 3124+ demo starts at 3:13.

Mic Preamp Shootout – Drum Overheads

Final Thoughts

What’s the only thing better than an API mic preamp?

4 channels of API mic preamps!

Simply put, the 3124+ is a world-class mic pre that delivers the legendary sound and punch that API is known for.

You really can’t go wrong with this mic pre.  Highly recommended!

API 3124+ Mic Pre

Check Price:


  • 4-channel solid-state premium quality mic pre
  • 4 front panel high impedance DI input for connecting instruments
  • 65dB of gain
  • Low noise design
  • LED VU metering
  • Balanced XLR input and output jacks
  • -20dB pad
  • 48V phantom power
  • Built-in power supply
  • Polarity switch
  • Single space 19” rack enclosure
Ultimate Mic Preamps Over $1,000 - SSL Alpha VHD-Pre

Solid State Logic, usually known as just SSL, is a pioneer and household name in the pro audio world.

They are a leading manufacturer of mixing consoles and analog processors, as well as the Duende line of DAW plugins.

Though an SSL mixing console is out of reach for anyone without considerable financial resources, the good news is that you can get that classic SSL sound for a fraction of the price.

The SSL Alpha VHD is a 4-channel mic pre that delivers ultra-clean tone, tube-like warmth, distorted grunge attitude, and everything in between.

Its mic pre design is the same as those found in SSL’s flagship Duality console that sells in the six figures.

The mic pre features SSL patented Variable Harmonic Drive (VHD) circuit that can be blended into the signal path for lots of tonal flexibility.


The Alpha VHD-Pre is housed in a single-space 19” rack enclosure and has a refined, sleek look.

On the front panel, each channel has Input and Output controls, and a VHD (Variable Harmonic Drive) control.

Each channel also has a ¼” instrument input jack and buttons for high-impedance, a 20dB pad, and 48V phantom power.

There is no traditional VU or LED metering, but the Pad switch includes a light which flashes red if the signal is overloading the input.

The rear panel has balanced XLR mic/line inputs and XLR outputs.

How Does It Sound?

SSL has always lived by the motto that a great mic pre should be designed to deliver the cleanest uncolored sound possible.  In their view, you can always add color to a sound later, but you can’t easily take any color away once you record.

The Alpha VHD-Pre, of course, delivers that ultra-clean sound that SSL is known for.

But with the view of expanding their sonic viewpoint, they have added the VHD control.  The VHD circuit is designed to add 2nd and 3rd order harmonic distortion, which gives a very musical and usable warmth to the sound.

The following video demonstrates some audio examples of the VHD in action on bass and drum kit, starting at 1:17.

SSL Alpha VHD-Pre Four-Channel Microphone Preamp Overview

Hi-definition WAV audio examples of the above are available here.

Final Thoughts

The Alpha VHD-Pre is a top-quality 4-channel mic pre section for serious recordists.  Four SSL mic preamps for well under $2,000 is an incredible value for anyone needing high-quality multiple inputs!

While most users would have loved the addition of a low-cut filter, it’s not a deal breaker.

In summary, the Alpha VHD-Pre is an investment in audiophile-quality sound that you won’t outgrow.

SSL Alpha VHD-Pre

Check Price:


  • 4-channel solid-state premium quality mic pre
  • 4 front panel high impedance instrument jacks
  • 75dB of gain
  • Ultra-low noise design
  • Balanced XLR mic/line inputs and XLR outputs
  • 20dB pad
  • 48V phantom power
  • Built-in power supply
  • Single space 19” rack enclosure
Ultimate Mic Preamps Over $1,000 - Grace Design M201

Grace Design’s story,  began in 1990 when Michael Grace started making custom mic preamps for his recording engineer and artist clients.

Over the years his Grace Design preamps have garnered a cult-like following for their pristine sound and no-compromises construction.

The M201 is their 2-channel preamp, the other models being the single-channel M101, the M103 channel strip, the 8-channel M801 and the M501 500 series module.

The M201 doesn’t disappoint fans of Grace Design’s gear…

The following quote from Hugh Robjohns, Technical Editor of Sound on Sound (SOS) Magazine sums up the majority of users thoughts on the M201:

“The Grace m201 is, in every way, a stunning microphone preamp. The build quality is uber-impressive, the feature set is comprehensive, the options are well thought out, the A/D stage sounds sublime, and the preamp itself is about as good as it gets.”

SOS magazine even stated that if their Technical Editor “calls a product ‘awesome,’ ‘stunning’ and ‘sublime,’ it’s probably time to sit up and take notice…”


The M201 is a dual-channel solid-state mic pre with built-in stereo M/S decoder.  It’s housed in a 2U double-space, 19” rack enclosure.

On the front panel, each channel has a large Input Gain control and an Input Mode knob that allows the user to switch between 48V phantom power, ribbon mic mode, hi-impedance, or 130V.

Ribbon mic mode optimizes the input for lower-output ribbon mics while deactivating the 48V phantom power.

Each channel has high-impedance ¼” inputs that can be used with instruments.

On the rear panel, each channel has balanced XLR inputs and 2 parallel XLR outputs.

M/S Decoder

The front panel includes controls for the built-in M/S (mid/side) decoder used for stereo recording.  A 12-position rotary switch controls the ratio from 100% mid (mono) to 30% mid/70% side.

Optional A/D Converter

The M201 is available with an optional 24-bit/192kHz A/D converter that can be installed from the factory or as a retrofit to existing units.

How Does It Sound?

As expected from Grace Design mic preamps, the M201 delivers pristine, accurate, uncolored sound without hype.

There’s a ton of headroom and very wide bandwidth that allows sound to be captured in the minutest detail.

Final Thoughts

The M201 is an audiophile-quality mic pre for anyone wanting the capture the cleanest, most transparent, highest-quality sound possible.

It’s built with premium components and attention to detail that you would expect with a mic pre at this price level.

No wonder it has become a must-have mic pre for recordings studios, music houses, and broadcast studios around the world.

Grace Design M201

Check Price:


  • 2-channel solid-state premium quality mic pre
  • Fully balanced transformerless design
  • Dual parallel XLR outputs for each channel
  • high impedance instrument for each channel
  • built-in M/S decoder for stereo recording
  • 64dB of gain
  • Ultra-low noise design
  • Rear panel XLR inputs and outputs
  • -20 dB pad
  • Polarity switch
  • 48V phantom power
  • 20-year EON transferable warranty on parts and labor
  • Built-in power supply
  • 2U double space 19” rack enclosure
Ultimate Mic Preamps Over $1,000 - Focusrite ISA 428 MkII

Focusrite started making their ISA (Input Signal Amplifier) mic preamps in 1985 when founder Rupert Neve (of Neve fame) was commissioned by George Martin (of Beatles fame) to create new mic preamp modules for the recording consoles at AIR Montserrat Studios.

One of those modules, the legendary ISA110, gathered so much praise for its sound that Focusrite decided to make standalone mic preamps to reach a wider audience.

The 4-channel solid-state Focusrite ISA 428 MkII mic pre is based on the ISA110 module and has the celebrated Lundahl LL1538 input transformer that helps define the Focusrite sound.

The Mark II second generation of this mic pre adds additional features that are highly desired for modern recording sessions.


The Focusrite ISA 428 MkII is housed in a 2U double space 19” rack enclosure.

On the front panel, each channel has a Gain control, Gain Trim control, and variable high-pass filter.

Each channel also has buttons for +30db or +60db gain, 48V phantom power, phase reverse, and Insert. These buttons are backlit for ease of viewing.

There is a separate front panel section with buttons to choose mic, line, or instrument input source, plus a high-impedance selector switch with 4 different settings, including the vintage ISA110 which provides the original classic Focusrite sound.

On the far left, four ¼” jacks allow you to connect instruments without needing a DI box.

The unit also has 6-step LED metering per channel.

On the rear panel, each channel has balanced XLR and ¼” inputs, XLR output jacks, and Insert Send and Return jacks.

Optional 8-Channel A/D Converter

The ISA 428 MkII is also available with an optional 8-channel A/D converter with resolution up to 24-bit, 192kHz.  The card adds 4 additional digital inputs, with ADAT Lightpipe input/output, word clock input/output and two 9-pin connectors for AES/EBU or S/PDIF.

How Does It Sound?

The ISA 428 has the clean, transparent sound you expect from Focusrite mic pres, with full-bodied lows, solid mids, and smooth, detailed highs.  It also has lots of headroom.

The variable impedance settings help get the best performance out of a mic collection, and can also be used to provide some color to the sound.

The following mic preamp shootout video showcases the ISA 428 on a drum kit.   It starts at 2:57.

Focusrite Preamps: LS56 vs. Octopre MKII Dyn vs. ISA 428 MKII

The next video has six-time Grammy nominated producer/writer/mixer Damian Taylor talking about the ISA 428 (and the ISA 828 8-channel version) in his studio.

The ISA 428 & 828 with Damian Taylor

Final Thoughts

The ISA 428 MkII version has made the great-sounding original unit even better.   It still has the Lundahl transformers, but Focusrite has added lots of features that make this mic pre very flexible.

All in all, it’s a very cost-effective way to add 4 channels of high-quality mic preamplification to your studio.

Focusrite ISA 428 MkII

Check Price:
Amazon | Guitar Center


  • 4-channel solid-state mic pre with Lundahl input transformer
  • transformer-coupled preamps
  • Instrument inputs for each channel
  • 60dB of gain
  • XLR and ¼” inputs and XLR output jacks
  • High-pass filter
  • Variable input impedance
  • Phase reverse switch
  • 48V phantom power
  • Built-in power supply
  • 2U double space 19” rack enclosure

Focusrite ISA 828

Be sure to check out the Focusrite ISA 828, the 8-channel version.

Check Price:
Amazon | Guitar Center

Hybrid Solid-State/Tube Mic Preamps

Ultimate Mic Preamps Over $1,000 - Universal Audio 4-710d

The Universal Audio 4-710d is the big brother of the highly-acclaimed Universal Audio 710 Twin-Finity.

The 4-710d is a 4-channel hybrid solid-state/tube channel strip mic pre with 4 award-winning Twin-Finity mic preamps.

The name Twin-Finity comes from the unit’s tone-shaping capabilities; on each channel, users can dial in vintage tube warmth or go for the high-gloss sheen that solid-state circuitry can give to the sound.

Each channel also has its own 1176-style compressor.  The legendary 1176 compressor is known for its incredibly musical sound.

Finally, there is A/D conversion for both digital and analog connections to your studio setup.


The Universal Audio 4-710d comes in a 2U double-space rack enclosure with UA’s cool brushed aluminum vintage finish.

Its unique design features four independent solid-state input amplifiers that simultaneously drive separate tube and solid-state gain stages.

Each channel has a front panel Blend knob that lets you dial in the tone you want, from transistor on the left to tube on the right.  This gives you lots of colors and textures to shape your sound.

Each channel also has switches for 48V phantom power, a 15dB pad, mic/line selection, low-cut filter, and phase reversal.

Finally, for ease of use, each channel has a high-impedance ¼” line input on the left front panel.

On the rear panel, each channel has a balanced XLR mic input, a balanced XLR Line input, a balanced XLR Line output, and Send/Return jacks.

There are 2 ADAT optical connectors with sample rates up to 192kHz at 16-or 24-bit resolution for connection to audio interfaces or other gear.

Word clock BNC In and Out jacks, and an AES/EBU DB-25 connector round out the rear panel connectors.

1176-Style Compression

The Universal Audio 4-710d has a true-bypass compressor on each channel, featuring the sound of their famous UA 1176 compressor.

Unlike most compressors where you get standard controls for attack, release, threshold, and sustain, there are only 2 specially tuned Fast and Slow settings.

On the one hand, this makes shaping your sounds quick and easy, especially for those not well-versed in using compressors.

On the other hand, having no control over threshold, release, and attack makes the compressors a little more limited in use.

Despite this limitation, the presets are solid and definitely give you that 1176 sound.

How Does It Sound?

NOTE: To get the best results, it’s always a good idea to let a tube mic preamp warm up for about 30 minutes.  This allows the tubes to reach an optimum temperature.

At lower levels of gain, the Transistor side of the Blend knob gives a clear, detailed sound. When the gain is increased the sound becomes brighter and more “in your face.”

With the Blend on the Tube side, the sound becomes warmer and rounder.

Pushing the input gain will create a thick distorted sound that, while probably not appropriate for vocals or organic instruments, would give guitars, bass or drums some meat and attitude.

The Line inputs also run through the Blend control so you can use them to add some nice tube warmth to guitars or synths if desired.

In the following mic preamp shootout video, the 4-710d demo starts at 3:13:

Mic Preamp Shootout – Drum Overheads

This video also demonstrates the 4-710d on a drum kit.

Exploring the Universal Audio 4-710d preamp: Recording drums (4 mics) with tone blending

Final Thoughts

The Universal Audio 4-710d is a great-sounding channel strip that gives you the warmth and musicality you expect from a tube mic pre, plus the accuracy and detail of a solid-state unit.
In addition, you get 1176-style compression on each channel to give your tracks a smooth, full, rich professional sound.

If you need 4 channels of top-quality mic preamps but also want both tube and solid-state options, then the 4-710d should be on your check out list.

Universal Audio 4-710d

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  • 4-channel hybrid solid-state/ vacuum tube channel strip with award-winning Twin-Finity mic preamps
  • Dual-path 285-volt Class-A tube and solid-state preamps
  • 4 front panel high impedance DI input for connecting instruments
  • 4 channels of 1176-style compression
  • 69dB of gain
  • Low noise design
  • Analog VU metering per track
  • Balanced XLR and ¼” input and output jacks
  • -15dB pad
  • 48V phantom power
  • Built-in power supply
  • 75Hz Low-cut filter
  • Double space 19” rack enclosure