StamChild SA-670 MK2 – Stereo Analog Tube Compressor

Historic Tube Compression

Next Batch:August 2024

(11 customer reviews)

Original price was: $5,990.00.Current price is: $4,990.00.

The StamChild SA-670 is our take on the most iconic and finest sounding tube compressor in history, the Fairchild 670.

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Recreating the finest sounding stereo tube compressor in history

The StamChild SA-670 MK2 is our take on the most iconic and finest sounding tube compressor in history, the Fairchild 670. Hand crafted by our small team in Chile, the Stamchild is a fully discrete accurate sounding replica of a Fairchild 670 with added modern features.

While developing this project we had two main objectives: first and foremost, the audio path had to remain as close as possible to the original units and secondly the compression curve had to be identical to the original. With this in mind we developed a few upgrades and carefully tested each component and its interaction with the circuit. After many months of research and tests we determined there was a way and so the StamChild SA-670 MK2 was born.

With custom made transformers, 18 tubes, original VU meters, knobs and a state-of-the-art power supply, the StamChild 670 has the some tone, character, compression curves and frequency response as an old Fairchild compressor at a fraction of the cost.

The Tubes

The StamChild 670 uses sixteen 6BA6 and two 12AX7 NOS tubes. Being the single most important part of the circuit and heart of any Fairchild comp are the peculiar compression curves that can only be achieved with 6BA6’s and 6386 tubes. It’s peculiar time constants are what makes the 670 so unique. We have tested every tube configuration out in the market and always end up going back to matching NOS 6BA6’s for this task. Each pair of 16 6BA6’s is carefully matched for a smooth and optimal compression and burned for 72 hours to ensure they last decades to come.

In the rare event that a tube fails we have made sure to have several sets of tubes matched for each client to replace them at any given point and stock ourselves for a lifetime!

The Iron

We outsourced these transformers to several manufacturers and ended up settling with AMI in the US whom painstakingly recreated the timbre of the original input UTC A26 input transformer as well as Sowter for the output transformer and control amp input transformers. Thanks to their meticulous craftsmanship we can confidently say the 670 recreates every drop of character of the original.

The Circuit and controls

The SA-670 is not only an exact sounding replica of the original but it also adds several modern features to help with modern day productions. DC Threshold, High Pass Filter, Dry-Wet blend Control and Output have been added to each channel as well as true bypass switch and a bypass for the transparent blend controls for the purist.


Each StamChild is handmade by a small team at our lab in Chile. To reduce the cost of manufacturing of these units we have made some modern implementations which do not affect the audio path and performance of the unit. We changed the tube-based power supply to a state-of-the-art solid state one which has no bearing on the sound.

With these measures we are able to bring the cost down while preserving the original tone without removing the character produced by the transformers and tube on the control amp and preserving the critical compression curves and timbre of the original.

Every unit is handmade and calibrated in our workshop in Chile where they get a full health check and are burned for 72 hours to ensure your Stamchild 670 will last for decades to come.

Stam Audio Engineering products are about sound quality first and foremost. Every component of every unit is premium quality and carefully selected to ensure our units match or even surpass the quality of high-end boutique gear.

100% satisfaction guarantee – if you don’t love your StamChild SA-670 MK2, we’ll refund you

If you’ve used an original Fairchild before, we’re extremely confident the StamChild SA-670 MK2 will put a big smile on your face every time you use it. However if you’ve never touched the original before, as gear-lovers ourselves, we understand that the only way to really know if this compressor is for you, is to put it through its paces. That’s why the StamChild SA-670 MK2 comes with a 30-day money back guarantee.

This allows you to get it into your rack and see how it impacts your recordings. If you love it (and we think you will!), great…keep the unit and create amazing music with it. If not, no problems. Just send it back to us and we’ll fully refund your purchase.

Fully Stepped Mastering Version is available per request.

Technical Specs

  • AMI UT26 Input Transformer
  • Custom Sowter Control Amp Input Transformer
  • Custom Sowter XL Custom Output Transformer
  • Custom Step-Up Transformers
  • NOS 6BA6 and 12AX7 tubes
  • DC Threshold
  • High Pass Filter
  • LAT-VERT Function
  • Dry Wet Knob
  • Output Knob
  • XLR inputs
  • XLR outputs
  • Voltage switch selector (115V or 230V)
  • Hand made in Chile
  • 6U, 250mm depth
  • 2-year warranty
  • 30-day money back guarantee


11 reviews for StamChild SA-670 MK2 – Stereo Analog Tube Compressor

  1. Alejandro Sanchez

    Alta máquina, una verdadera bestia! En mi opinión no hay mejor manera de describirla. Es una máquina viva, en el buen sentido de la palabra, te exige que escuches atentamente, que sientas como interactúa con tu música, tienen un tremendo sonido, es dificil encontrar la palabra justa, porque no es HiFi, mucho menos LowFi, la distorsión no es como la de un equipo barato que mas que excitar, rompe toda la vibra, el SA-670 agranda, controla, tiene personalidad pero puede tratar al audio con cariño y suavidad. Stam la va a romper con este equipo!

  2. Antony Mosley

    English Translation of First Review:

    High machine, a true beast! In my opinion there is no better way to describe it. It is a living machine, in the good sense of the word, it demands that you listen carefully, that you feel how it interacts with your music, they have a tremendous sound, it is difficult to find the right word, because it is not HiFi, much less LowFi, the distortion It is not like that of a cheap equipment that more than excite, it breaks all the vibe, the SA-670 enlarges, controls, has personality but can treat the audio with affection and softness. Stam is going to break it with this team!

  3. Audio 911

    In today’s world of instant gratification of buying something on the internet today and having it at your doorstep tomorrow morning, ordering a piece of audio gear made by Stam must seem crazy to 99.9% of people on Earth. When a new Stam product is announced, it’s usually a computer mock up and a circuit that being designed by Joshua van der Stam in Chile, but if you’re one of the first to pre order one, you’ll get a discount! Here’s where the big leap of faith and patience comes in. I took that leap a few years ago with the Stam Audio SA4000 compressor. I put down my $100USD via Paypal and rolled the dice on an unknown company on another continent with not much of a track record. If I never saw my money again, it was no big deal. I’ve purchased plugins for my DAW for five times as much, and to this day, I still never use them and now are not compatible with newer DAWs. Stam Audio was in its infancy, and a business model of getting down payments to source the parts and get them built was unheard of in the industry. Any problems, and there would be a lot of angry customers. The SA4000 took about 2 months to arrive, but when it did, I was very impressed by the build quality. After putting it into service, the sound was equally impressive. I purchased the SA4000 because I’ve only owned Neve consoles, loved the SSL master buss sound, but I didn’t want to dish out the big money for an SSL FX384 or a used SSL 4000 console.

    Since I purchased the SA4000, Stam Audio has really ramped up the product line of classic design preamps, EQs, and compressors as well as microphones. I was pretty well stocked up in those departments at my facility, so I didn’t need to make another purchase until the BIG announcement came in 2018. The Holy Grail of compressors was being brought back to life. The Stamchild 670 stereo tube compressor was announced!!! I had the opportunity to purchase a Fairchild 670 in 1990 for whopping $10,000USD, but I thought a Lexicon 480L would be a better investment for my studio because I could rent the unit out to other facilities in the area and make some extra money when it wasn’t in use. Well, the 670 kept going up up up in resale value and the 480L kept going down down down. I guess a Fairchild 670 would never be in my budget in this lifetime, so I resorted to using plugins to get “that Fairchild sound”.

    I took the leap of faith again after the BIG Stamchild 670 announcement and put down $500 on a pre-order. The Stam website listed a delivery time of 3 months which was not to too bad considering the SA4000 took two months to deliver. Following Stam Audio on social media became very difficult after putting down my deposit. Angry posts kept showing up about lack of delivery of products ordered months earlier and the Stamchild 670 release dates kept being delayed because of numerous things that were out of the control of Stam like sourced parts and custom transformers. With new products being announced just about every month, I started to rethink if the Stamchild 670 would ever become a reality. I reminded myself of the “Good, Fast, Cheap, pick any two” rule, so I subtracted “Fast” from the equation. Stam Audio gear it’s not going to be ordered online today and show up tomorrow like a 1-800-Sweet-Gear store, but it will be Good and Cheap (inexpensive). In fact, I know a guy that has been trying to make his own Fairchild clone for years at the cost of almost $10,000USD and it’s still not finished!

    I put aside the idea that the Stamchild was going to show up by the end of 2018, and watched pictures of the test units on the bench over the next few months on the Stam Facebook page, and then I got an unexpected email from Stam with the subject line: Stamchild Invoice. I almost panicked! I was lulled into waiting so long that now I have to come up with the rest of the payment in order for it to ship. I made the payment and received an email from Stam with the DHL tracking number. I checked the DHL website every four hours to watch the progress from Chile to the United States and eventually got a text message from DHL alerting me that the unit was on the truck and would be delivered by the end of the day! The Stamchild 670 was delivered with a personal thank you for my patience for waiting so long. I opened up the double boxed unit, and there it was. Forty pounds of tube compression heaven! I couldn’t get it plugged in fast enough and hooked up to a sound source. Once I plugged it in and let it warm up (literally), the sound coming out of the Stamchild was better than the sound going in. Magical, yet almost transparent. It was doing it’s thing! I quickly played around with some of the input and gain reduction settings as well as the ratio presets and filters. Wow! I really loved the sound of the WET/DRY setting in the 7-8 position where you get a nice blend of the original signal and make up the wet signal by the front panel input gain. The final make up gain is set by the output knob, which never needed to go beyond half way. The unit offers the perfect amount of much wanted musical Total Harmonic Distortion to bring the sound to life. With eighteen vintage tubes, six custom transformers, and the retro vintage knobs, the Stamchild 670 is now the centerpiece of our outboard gear at Dirt Floor Recording and Production in the United States and it will be in daily use for years to come.

    Joshua van der Stam is very ambitious, very detail oriented when it comes to his designs, and his passion for sound quality is a bit off the charts. In fact, he may be too ambitious. To say the wait time to get a unit delivered is long is an understatement, but when it arrives, you’ll know the sound quality is going to be outstanding. Stam products are a work of art and are not mass produced by robots. When your unit arrives, open up the lid (with the unit unplugged!!) and take a look inside and you’ll see what I mean. Thank you for your hard work and dedication to making high quality audio equipment and making the Stamchild 670 available to us Josh!

    Steve Wytas
    Chief Engineer
    Dirt Floor Recording and Production

  4. moscozzi12

    I was first approached by Stam Audio late January 2019 with an offer of a “30% discount to an item of your choice from our catalogue”
    Well that got my attention so I scootered around the site and landed on the StamChild SA-670 page. It looked so good and authentic.
    I thought, if it sounded as good as it looked then it will be a great addition to my studio. Then I saw the price and to be honest, was a little skeptical as to how good it could be at such a reasonable price, however with the full refund (including shipping) satisfaction guarantee, I went for it. I paid the $500 deposit and was informed it will be around a 10 week delivery time.

    Six months later(!) the unit finally arrived (serial number 16). My first impression was wow! This is a quality build, no corners cut. The workmanship inside the unit is equally impressive. I haven’t seen work like this since Pete Cornish hand built my pedal board in the late 80’s. Anyway, the real test was how it sounded and its usability. I tested it on vocals, instruments, 2 bus and mastering chain. I was blown away with how good it sounded. It did everything that was expected of it and more. The added mix/parallel control is a genius move. As an earlier user stated, between 7 & 8 seems to be a sweet spot for the blend. My next move was to compare it to some of the Fairchild plugins, and although the convenience of a plugin is a factor, there is just nothing that compares to an analogue sound going through 18 tubes.

    In conclusion, Joshua Stam does top shelf work and stands by his gear. Yes the delivery delays were frustrating but a few hours into using the Stamchild the frustration just melted away. I, for one am going to order more of his products before word catches on and the price goes up 🙂

    Congrats Joshua on an outstanding build & I look forward to checking out more of your products.

    Michael Cozzi
    Owner Moscozzi Studio

  5. Peter Jacobs

    Well, first off, due to a miscommunication about payment (which is as much my fault as anyone’s), it took me WAY longer to get my Stamchild than originally planned, so I had a LOT of time to build anticipation about it. That said, I’m going to leave this review as short and sweet as I can think to. I plan on making some videos showing off what the Stamchild can do, and you will hear future mixes done at Black Dog Recording ALL going through the Stamchild on my stereo bus, because it is without a doubt going to be on there for everything I mix! It’s UTTERLY ASTONISHING how good this piece sounds for the money. It’s built very well too! I have Crane Song Trakkers, an IGS TubeCore, drawmer 1987, and a UK Sound 276 to compliment my Trident 88 console, and there is not a single piece of gear on my rack that I am as blown away by as much as this! God forbid anything happen to it, it’d be instantly replaced with a new one. For this price point, it’s going to be damn near impossible to find anything with the euphonic fullness and depth this imparts, and there is just some indescribable “sparkle” it imparts without getting bright or harsh in ANY way. The first thing I thought when I ran a mix through it was, “Wow, that’s what a record should sound like!” Thanks Joshua and team! I’ll be eyeing more from you guys. Keep building stuff of this caliber!

  6. Elias Assunção

    it is one of the best equipment I had the opportunity to use, test.
    It has a very pleasant sound, with a texture that works in all musical styles.

    It is very easy to move, and with toothed knobs, super resistant.
    Anyway, it is a compressor that can change the life of any studio. – Brazil

  7. Ola Göransson

    Just wow!
    I received my Stamchild 2 days ago and have now tried it as a drum bus, 2bus and vocal compressor. First up I ran some drums hrough it and compared it to the same drums going through my Stam Sa4000. There’s a depth and clarity that is amazing. And the sa4000 is not bad. Same with the 2 bus. So i hooked up my U67 to an La610 and then to the Stamchild and recorded a few vocal takes on a song I am currently tracking. Then comparing it to the same chain, but with a Teletronics La2a instead of the Stamchild. Not even close! I had to re-track the vocals today. There’s a 3D quality and depth to this compressor that is just fantastic. The La2a may be up for sale….

  8. Henry Lai

    Yes it was a long wait, but when I first plugged it in, I knew all the wait was worthy. It improves my mix by giving it more presence, depth and width. I tried to reproduce this with many plugins but have been able to achieve the same feel. But hey, if I can do it with a hardware, why bother wasting my time going through all the software world? This is magical. And handymand in Chile , not China, already a big plus. So if you can afford to wait, or invest your time, this is the best you can get for your studio.

  9. Jamie Sitar

    This is the rhythm section sound that I’ve been trying to get forever! My Stamchild lives on my drum/bass buss when mixing. The Wet/Dry control allows me to do some very heavy compression in parallel and fatten things right up without losing any detail. The bass is thick and the treble is euphnic without being harsh. The stepped controls (all except for the output -which stays on full anyway) make recalls a breeze.

  10. Zyon Odinson

    I have had my system for a couple weeks now and I must say that I am beyond impressed with the quality of this compressor. I have been using the Waves and UA plugin version of the Fairchild 670 for years. I have always loved the color it smoothness it brings to my mix or master. Now that I have bought this box, thanks to Josh Stam (deeply appreciated), my clients are even more amazed by the sound of their music. Additionally, making the switch from plugin to analog was totally easy because all of the controls are stepped and can be easily recalled. Blessed!

  11. Dave Gregg

    It was PITA waiting for 670 mkII to reach my Hollywood studio, but understandable given that Stam team was overwhelmed with orders at time. I tested it straightaway with my proven favorites Thermionic Culture Phoenix, Tube Tech CL2A and DW Fearn VT7. The first, second and all following impressions are always same yes, this is it !! This piece of real estate is to stay here and do its duties on mixbus of 48 ch Neve analogue console. It can compete with anything bellow the skies. No 10k+ USD tube compressor is a threat to Stam’s Fairchild 670 mkII. It is among 10 best purchases I made in 30 years. Kudos to Joshua and team for this achievement.

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We’ve been using it on every mix. It’s working seamlessly going back and forth between the two units (Original Fairchild 670)

– Tony Maserati

  • Tony Maserati with StamChild 670 MK2

  • We’ve been using it on every mix!!

  • Eddie Kramer with the Stamchild 670