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J. Rockett Audio Designs Airchild 660 Compressor Pedal Review

Let's take a look at the brand new Airchild 660 Compressor from J. Rockett Audio Designs. But first, a bit of background on the legendary original Fairchild Six Sixty Compressor released in the late 1950's. The manual for the J. Rockett Audio Airchild 660 includes a nice straightforward description which I am quoting here: "The original Six Sixty Compressor was designed by Rein Narma, who had worked with Les Paul to build a recording mixer to use with Les Paul's Ampex 8-track. Les Paul asked Narma if he would build a compressor/limiter. Sherman Fairchild, who was friends with Les Paul, learned of the compressor and licensed Narma's compressor design, hiring Narma to be chief engineer at Fairchild Recording Equipment Corporation. The first 10 Fairchild 660’s were built by Narma himself. The first unit was sold to Rudy Van Gelder who used it to cut lacquer masters for Blue Note Records and Vox Records . The second unit went to Olmsted Sound Studios in New York City and the third 660 built went to Mary Ford and Les Paul."

The Fairchild Six Sixty is consistently regarded as one of, if not the best, compressor ever made. Quoting the J. Rocket Airchild manual again: "Abbey Road Studios purchased 12 660s after staff engineer Peter Bown heard it during a visit to Capitol Records in America and used it on recording sessions for the Beatles, primarily for vocals. Beginning in 1966, Geoff Emerick began using the 660 on Ringo Starr’s drum tracks as well as piano and guitar tracks. As of 2014, Abbey Road still had 8 of the original 660s purchased in the 1960s." This new pedal from J. Rockett was designed with inspiration for the original, albeit in a much smaller form factor and with limited controls, and also a much smaller price tag. It is a VCA style circuit design. I have not yet had the fortune of experiencing an original vintage Six Sixty though I certainly hope to one day. Those things are few and far between these days and extremely expensive. So, I can't speak to the similarities and differences in tone, feel, and compression style between the legacy device and this new pedal compressor from J. Rockett. But I'll certainly give an honest reaction to this new device. First, let's start with the controls. There are just four knobs on the face of the pedal.

The Output control regulates the overall output of the pedal. There is a fair amount of gain on tap. The Tone control is there to introduce a bit more lows or highs into your signal. At 12:00 it sounds pretty neutral but above 12:00 it boosts the treble and cuts bass. Turning the dial the opposite direction, you get the opposite effect — more boosted bass and reduced highs. The result can be rather dramatic. With bass guitar, turning the dial a little more to the right of noon, say 1:00 or so, adds a nice bit of sparkle or sheen up top which is real nice. With guitar, turning the knob a little to the left of noon can fatten up single coils and add a nice bit of warmth. If you use multiple instruments with this compressor, this tone dial is quite useful to quickly tweak your tone. Maybe you feel you are missing just a little bit of highs or lows, well, this tone control makes it easy to tweak on the fly. It is very natural and quite clean sounding. The compression circuit itself offers up just two controls: Blend and Threshold. Threshold controls the amount of compression introduced to the signal. In this case, the definition of threshold should be thought of as just increased compression. Turning the dial more clockwise increases the amount of compression. All the way counterclockwise is fully off, and all the way clockwise is fully compressed. This threshold control is highly interactive with the output control. The more output you send out the more gain so the effect of the compression circuit will be less noticeable with a hotter output. You need to use your ear and experiment to fully experience the nuances. Since every amp and pedalboard configuration is different, having a tone control on a compressor can be invaluable. The Blend control allows you to blend your dry signal with the compressed signal which can be helpful for retaining some of your original attack when dialing in higher levels of compression. Rotating the dial more clockwise dials in more compressed (wet) signal. Rotating more counterclockwise results in more of your original dry signal, and less of your compressed signal.

This is one of those compressors I think you will be able to hear differences right away simply by turning it off and on.

The Airchild 660 introduces a real nice "chime" or "lively" feel to your signal. I see it as more of an always on type compressor.

In one sense it isn't highly versatile in that it doesn't offer a whole lot of control to various aspects of compression. There is no way to adjust the attack and release aspects of compression. There is no true ratio control. On the other hand, somehow playing through the J Rockett Airchild 660 compressor feels natural and highly responsive. The automatic logic of attack and release taking place inside the circuit design works well which makes for a pedal that is simpler to dial in. If you like simplicity in a compressor, this is one to look at.

To get started, I recommend setting the output and tone control at noon and turn the compressor on and off to see how close you are to unity. Adjust the output accordingly. Then set both the Blend and Threshold dials to 3:00 which introduces a good amount of compression. Listen to what you hear and then adjust accordingly. I really like the Threshold control somewhere around 3:00 and the Blend control between noon and 2:00 which makes for a fatter and lively sound. Interestingly, this setting sounds great to my ear with both guitar and bass. Finally, adjust the tone control to taste for a little more low end or some shimmer up top. When we talk about compression, we are typically referring to the reduction of dynamic range. The highest peaks and the quietest parts have fewer dB of level difference between them. The result is that with a compressor we can help support or bring to life soft notes as well. It's the latter where the Airchild 660 really seems to excel — it really does seem to bring life to your overall signal. With bass guitar, lows are maintained quite well. There is certainly squashing occurring but in a natural way. Lows don't necessarily become bigger, instead they are controlled in a balanced way. I was impressed with how the lows were handled and never felt choked. Even a 5-string bass doesn't trip up the compressor design or distort with an aggressive attack. The manual also says this: "The typical [Six Sixty] Iconic circuit tends to crush the sound more like a limiter but has also cemented that sound into certain genres of music which is a great sound if so desired. We wanted to make available a compressor that works like a studio compressor which enhances harmonic richness and evens out transients without crushing the entire spectrum."

I definitely hear the harmonic richness and I don't feel like the circuit crushes the sound, so check both boxes as success.

If you play an inherently dark sounding instrument and wish it had a bit more "spice" or "brilliance", well then you should try the Airchild 660 compressor. On the other hand, if compression to you equates to smooth and buttery, the Airchild 660 might not be your thing.

It's not that it is aggressive, it is just a livelier sounding compressor than many others on the market. J. Rockett literature says the Airchild 660 compressor "Gets the 660 growl." That might be a good way to put it. It's not that the compressor is "distorted" or "angry" sounding. It's not that it's the opposite of smooth and rich sounding either. Words like "brighter" or "present" come to mind.

It manages to sound and feel natural, yet there is obvious coloration in an unobtrusive or highly EQ'd sort of way.

I feel like my strings are more bouncy feeling and that I can play faster with this compressor. This pedal has a real nice form factor. It is quite small overall and notably less tall than most other pedals on the market. This is a custom enclosure design. Top mounted input and output jacks is something I prefer as is the top mounted power input jack. The Airchild 660 manual describes the pedal as "over built". It definitely has weight and feels solid. I personally think it looks great with a nice retro feel. I really like the knobs. Here's a couple of pictures showing the Airchild 660 beside a couple of other compressors to get an idea of size.

There is a red LED that illuminates when the pedal is activated by the footswitch. Sadly, there is an audible "pop" when the pedal is activated. If you use it as an always on device, this is really no issue, but it is there. This one really surprised me, in a good way. I think it makes for a great choice as an always on tone enhancing compressor. I really like the form factor, build quality, and tonal/compression variety even with so few controls. It sounds really good with guitar and also great with bass, though it excels with guitar.

If you already have a compressor you are content with, well, you might want to give this one a go anyway. It is likely a different flavor than you are used to, and you might be as surprised as I was as to how much you like it.

The Airchild 660 requires 9-volt center negative power, and it draws just 20mA. With a retail price of $229 the price isn't too bad either. At least not compared to many compressor pedals these days. Pros: • Tone • Lively feel of compression • Quality build • Form factor • Pedal design (in my opinion)

• Price to value Cons: • Audible pop when engaging (so best left always on) • Not the most versatile • Not a great device to use as a limiter if that's what you need • Maybe not smooth enough sounding/feeling for some Retail price: $229


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