AUDIOSCAPE PROUDLY INTRODUCES THE MK-609!

AudioScape proudly introduces the MK-609 Precision Diode Limiter/Compressor. Well known as one of the most classic bus compressors ever made, the original 33609 was based on an older design, the 2254, dating back to 1969. The 2254 bus compressor was integral to some of the most iconic British consoles of yesteryear. Utilizing a diode-bridge circuit topology, this design controls dynamics by constantly listening to the side-chain, who’s control voltage is used to adjust the amount of compression applied; as the control voltage increases, the output gain decreases. This design allows for subtle compression as a stereo bus compressor when you’re just looking to grab peaks, but can become much more aggressive when used on more dynamic tracks, like vocals and drums..

MODERN UPDATES FOR THE MODERN WORLD

Featuring two independent channels, each has a discrete LIMIT and COMPRESS section, either of which can be bypassed, both with their own Threshold and Recovery controls. The COMPRESS section also has a makeup GAIN control and variable RATIO switch. Normally used in the STEREO mode, QUAD mode activates a connection on the rear panel that allows multiple MK-609s to be linked together.

The new MK-609 improves on the original design by adding a few new features making it more versatile in the modern studio workflow. We’ve included a high-pass filter on the sidechain, allowing more precise control over how it triggers compression, with settings at 50 and 100 Hz. Also new for this iteration is an additional “Super Fast” attack setting on both the limiter and the compressor that gives the MK-609 the ultimate control in any application, including kick and snare! Optimized for more subtle bus compression, the original was excellent for that and vocals, but not useful on faster attack, more percussive sources, the MK-609 corrects for that. It’s designed to have the harmonic richness so associated with the original British maker, whilst being a much more versatile tool in today’s recording studios. The character of compression is altered in a very useful way. You can really ‘dig in’ to both the compressor and limiter sections now. We found ‘super fast’ to be the MOST useful mod you could add to this circuit, and we tried everything under the sun!

One other upgrade we’ve added is having the makeup GAIN available even when the compressor is switched out. Which means that if the MK-609 is being used as a limiter-only, with the compressor out, makeup gain is still available for the limiter, a function not available on the original versions. We actually made this feature reversible back to the original design by way of an internal user-accessible jumper, if that’s your preference.

THE RARE BITS THAT MAKE IT GO!

A deep dive into the original Metal Knob revision of this circuit revealed a lot of unique parts that weren’t used in later revs. We also discovered that that there were parts added in later revs that aren’t even in the “Metal Knob” iteration of the 609. We had to trace and account for every part. So in true AudioScape fashion, we scoured the surplus market here in the USA. Having access to these original parts is one of the advantages of building products here.

Let’s break some of these down:

- U410 silver can Dual FET (pictured). This is a decades-old obsolete dual FET used in the originals; others just pop a pair of J109’s in place of them and call it a day. But this is an important component in the compression section. It took some time, but we’ve secured a good lot of them. One could even argue that it’s not truly a “Metal Knob” version without this part!

- Original issue BC184C NPN transistors (pictured). This is the most used transistor in the old school 609 compressors and old N style preamp designs. This is why we use these BC184C’s exclusively in our MK-609 and the V1290 preamps. If you want that vintage sound, you have to get the right parts. Plain and simple.

- BC214C PNP transistors that were also originally used, no corners were cut. We searched them out and we’ve nailed it.

- BC441 and BC461 silver-can transistors. Used in the original. We searched them out and found NOS ones for the main amp cards and BA440C discrete amps in each channel.

- Original JAN blue 1n4153 diodes. These were in our Metal Knob compressor, so we searched them out and found a healthy stock in the UK.

- We even went as far as to find the original locking power toggle switch and the identical power jewel bulb as the original vintage Metal Knob we have here. These are military-grade parts and come at a great expense (like buying another transformer).

- Notice the component layout on the original Metal Knobs, it is quite different right before the meters. This control layout is unique to the circuit design of the metal knob revision itself. Don’t be fooled by someone popping metal knobs on a modern control layout and then chucking small SMT parts( like in your phone) on the pcb (which is game over for tone)

THE STORY?

The only real story is that this particular legacy piece is so loved in the industry that it took Chris more than four years of development to create a unit worthy of the classic British original. Painstaking care was taken to recreate the original “Metal Knob” version as faithfully as possible. Like all of AudioScape’s legacy builds, NOS parts are used throughout when available, new parts where it makes sense for reliability, and in-house built recreations of the original PCB, transformers and other components as needed.

The creation of the MK-609 started with you. Every die-hard AS follower has been clamoring to experience our take on this for years, so we answered the call!

At AudioScape Engineering Co., we believe in creating boutique analog hardware for a reasonable cost.  No Compromises.  No BS.  Many years of research, development and experimentation have gone into each product resulting in units that can be your daily-driving, rock-solid workhorses for years and years to come.  Each and every unit we sell is hand made in small batches, one at a time in the USA - right here in our Daytona Beach, Florida facility!

FEATURES & SPECS:

• Handcrafted in the USA

• Custom-Wound transformers matching the original Marinar/St Ives spec

• Exact replication of the BA440C Amp cards (pictured)

• NOS transistors (found in the original units) utilized in Crucial Areas of the Compressor/Amplifier Sections

• Period-Correct Attack & Release Time Constants

• Cornell Dubilier Silver Mica Capacitors

• Tantalum and Styroflex Capacitors throughout, matching the 1:1 with our original metal knob layout

• Period correct Carbon film resistors used in the original circuitry, 1% precision resistors used for the modification sections

• Fully Variable Input/Output and Attack/Release

• Comp Attack 3 way mini toggle Switch (Fast, Slow, and stock))

• Limit Attack 3 way toggle Switch with extra mode added (Fast, Slow, and Super Fast)

• SC-HPF 3 way mini toggle switch for 50Hz or 100Hz (or stock/off) of sidechain filtering

• Additional gain mod jumper inside to allow gain to be active when comp mode is bypassed(original did not have this option)

• Original Style Ratio Control (1.5:1/2:1/3:1/4:1/6:1)

• Lorlin UK rotary switches and custom made stepped potentiometers

• Electronically Balanced +4dBu circuitry

• Custom Vintage-Styled dB Gain-Reduction Meter

• Original toggle switches and Pilot Light

• Highest-Quality US made Recreation Metal Knobs

• Real Metal Neutrik XLR Input and Output Connectors

• Internal 120V/240V Power Supply, everybody worldwide welcome!
  

  **specifications, parts & pricing subject to change because sh*t happens ;-)

DOCUMENTATION:

• COMING SOON!

HEAR IT IN ACTION! Coming soon.

USER PHOTOS:

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