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Heritage Audio HERCHILD Model 670 Ardent Edition Rackmount Vintage Stereo Tube Compressor


Heritage Audio HERCHILD Model 670 Ardent Edition Rackmount Vintage Stereo Tube Compressor


Manufacturer's Description

HERCHILD Model 670: The Ardent Edition

The legendary sound of Ardent Studios now available with this limited edition Vari-Mu Compressor.

When you hear records made at Ardent, you are listening to the heart and soul of Memphis and from here on out, that spirit is captured by the HERCHILD Model 670: The Ardent Edition.

Ardent Recording Studios is one of the most iconic music studios in the world. Known for its creative energy and technological excellence, it’s been home to a wide range of unique and talented recording artists, producers, and engineers, and has witnessed the creation of many timeless recordings that have influenced the direction of modern music and music production.

So it is easy to understand that when Ardent Studios first contacted us to evaluate the possibility of having an Ardent Edition of our HERCHILD to substitute their original Fairchild units we could barely believe it.

Since its release, the HERCHILD has established itself as the industry reference for “Vari-Mu FAIRCHILD” compression all over the world, but with this request from Ardent we now had a new challenge…a unique opportunity to take it to another level.

But, what is so special about the original Ardent’s Fairchilds? Ardent’s team modified the attack and release times of their original units in the early 70’s so that the time constants were faster and, therefore, more usable for modern recording studios at the time. These mods were first used to track Jimmy Page’s acoustic guitars on Led Zeppelin III and it has been a best kept secret…until today. After receiving the pencil on paper notes from the original modifications, the Heritage Audio team has worked together with Ardent’s to nail the time constants of the original and after several months the HERCHILD “Ardent Edition” is a reality. Ardent’s team were so impressed by the performance of the HERCHILDs that they have changed their original units for 4 HERCHILD 660 and a HERCHILD 670.

For almost 60 years Ardent has been a special creative space for a diverse and world-renowned clientele; recording artists such as Led Zeppelin, Sam and Dave, ZZ Top, R.E.M., Isaac Hayes, The Staple Singers, Stevie Ray Vaughan, BB King, The Bar-Kays, The White Stripes, Big Star, Bob Dylan, The Raconteurs, The Gin Blossoms, Stevie Wonder, Steve Earle, Smashing Pumpkins, The Allman Brothers… just to name a few. Now you can own a legendary piece of gear that has been the centerpiece of so many multi platinum recordings for decades.

The HERCHILD Model 670: The Ardent Edition will be produced only on request and in very limited units.

For years the industry has referred to this tube-based beast as something special, unique and even magic-like.  The original Fairchild has indeed been an essential part of the sound to so many hits during several decades..  It certainly has earned its title as the ‘granddaddy’ of all compressors.  Being based around 22 tubes and 9 transformers you can be sure the HERCHILD Model 670 will imprint its signature sound all over your tracks providing that familiar tone that we’ve all come to love.  Although it was originally designed to be used for cutting lacquer masters for vinyl albums it didn’t take long for engineers to realize that it could do much more.  It soon became an essential studio tool for many innovative artists, engineers and producers and could be found in most professional studios.

As there were only about 500 units originally produced there just simply aren’t enough to go around for everybody.  Add to that the original requires quite a lot of special maintenance and after nearly 60 years there just simply aren’t many still in good shape.  So that’s where Heritage Audio comes in…

Heritage Audio has been able to successfully follow the original design and trace the necessary components to provide a modern day alternative.  It’s taken us years, but we’ve finally produced something so special that it’s capable of letting the old grandaddy take a long deserved rest, and make room for the new blood to take over. 

It’s been quite a long journey, from sourcing thousands of NOS vari mu tubes from all around the world to commissioning the best names in the industry for making the needed custom transformers.

While staying true to the original in terms of response and sound, we’ve been able to add a few things to make it more practical in modern day studios.  First off we’ve given direct access to the continuously variable slope control (DC Threshold).  This is something that makes the compressor so much more flexible and was only available on the original via an inconvenient screw adjustment hidden from immediate access. Then there’s the SC FILTER.  Nowadays, it’s just about impossible to fathom a compressor without this feature as it’s become so important in everyday use.  Here we’ve provided 4 different frequencies to choose from to precisely tailor your compression needs. The HERCHILD Model 670 is a two channel unit so you have the option to use them independently or linked together.  There are actually 4 modes of operation:  Individual, Link(Stereo), LAT/VERT(MID/SIDE) & LAT/VERT Link.  Using the LAT/VERT mode provides a whole new world of options to your mix.


  • Fully tube-based compression.
  • Modified the attack and release times to perfectly match Ardent’s original units.
  • Side chain filter for modern day needs.
  • Immediate access to the continuously variable slope.
  • LAT/VERT mode makes MID/SIDE processing possible.
  • Clean, intelligent design to guarantee many years of use.
  • That legendary sound, finally available to everyone.
  • Ultra-limited edition made upon request through Heritage Audio distributors only.