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Source Audio Atlas Compressor Review

The Source Audio Atlas compressor is a powerhouse collection of several compressor greatest hits rolled into a small pedalboard friendly enclosure. After 10 years of research and new ways of thinking, the Atlas was born.

If there was ever a one-size-fits-all compressor, my vote goes to the Atlas.

That's the Tl;DR version of this review.

Out-of-the-box the Atlas is loaded with six classic compression engines and deep editing capabilities via the Source Audio Neuro Editor. It is also MIDI compatible. Let's get one thing out of the way. I used the word "deep" to describe the editing capabilities of the Neuro editor because you can adjust literally everything. True, other compressor manufacturers have released devices with software editors such as the Spectracomp from TC Electronics and the Hyper Luminal from Darkglass but the capabilities of Source Audio's offering is in an entirely different league. It is beyond the scope of this review to provide a manual of how to use the editor but know that it is a robust offering and intuitive once you get to know it. Give it a chance. If you aren't satisfied with any of the default compression offerings built in you can adjust any of them to better suit your needs. Think the timing of the release and attack, blend characteristics, high pass filtering parameters, fully parametric EQ points, input and output gain settings, adjustments for hard/soft knee and even setting up series/parallel compression. It's all done simply by connecting the Atlas Compressor to your computer via the provided USB cable and installing the Neuro desktop editor to your Mac or Windows computer.

There is so much more that could be said about the capabilities here but that will be for another review.

But is the Atlas good enough "out-of-the-box"? Do you have to mess around with the editor before the device becomes usable? It is absolutely great out-out-of-the-box and you have not one, but six compression types to experience by default. If you are the type that wants to just plug-and-play, the Atlas has you covered. But you might want to check out the Neuro community to see other compression engines being build by the Source Audio community at least. Those are also found via the Neuro editor. Initially, the 6 preset compression engines are suited for guitar. If you play bass, use the editor to change that to 6 presets optimized for bass. Cool! You can also switch to bass mode by holding the control button on the back when powering up. See the manual for more details. Let's look at the device itself. The enclosure is a real nice green brushed aluminum top with black enclosure. There are 4 knobs, one three-way toggle switch, a soft press foot switch and two LEDs. On the sides are two sets of input an output jacks allowing for manual or stereo routing. Create two entirely different compression presets and run them in series, parallel or run each to a separate output.

INPUT 1 is the primary input for guitar, bass, or other instruments. It can also accept line-level inputs and will work in your amp’s effect loop. Use the secondary audio input for stereo sources or as the data connection to your mobile device when using the Neuro App. OUTPUT 1 is the primary audio output. Connect it to your amplifier, recording interface, or the next device in your effects signal chain using a mono (TS) ¼” cable. The ring contact on OUTPUT 2 acts as a data connection for the Neuro App, passing data from the Atlas to the next Source Audio effect in your signal chain. You can daisy-chain the Neuro App data regardless of whether OUTPUT 2 is configured to output audio or not. The power supply must be regulated at 9 Volts DC (direct current), able to source at least 160 mA (milliamps) of current, and the plug should have a tip-negative, barrel-positive polarity. The 3.5 mm CONTROL INPUT port connects to external control devices such as the Source Audio Tap Tempo Switch, Source Audio Dual Expression Pedal, and the Neuro Hub. You can learn more about this on the Source Audio website. The USB input is used to connect the device to your computer to sue with the Neuro Editor.

There is a special press-and-hold function on the foot switch. Press + hold the foot switch down while the pedal is bypassed to bank to Red LED (ALT) Mode for more presets.

The small button on the top of the pedal labeled ALT is used to enable or disable external control. It is also used to control the alternative parameters of the controls on the face of the pedal. You press + hold the ALT button while turning any of the control knobs to access their alternate parameters which are indicated by the words outlined in white behind the four knobs. For example, the alternate function of the Output control is the release parameter. There is a small LED between the Threshold and Ratio dials which illuminates red when in alternate mode.

When the pedal is engaged, the large LED between the Blend and Output dials illuminates green. It can also serve as a gain reduction meter which can be enabled in the Neuro editor or by holding the control button and tapping the foot switch to toggle the LED operation on/off. This was one of the first things I enabled in the editor because I am a fan of visible LED gain reduction metering. When using a compressor it is certainly important to rely on your hear to hear what the compressor is doing. But having a visual aid can add more certainty to your exploration and is certainly helpful with on-the-fly changes during a gig. This LED has nothing on a full array of LEDs like the Empress MKII or Becos Stella but is still useful.

The THRESHOLD Knob Adjusts the decibel level at which the signal becomes compressed. Turn counterclockwise for a lower threshold (earlier compression), or clockwise for a higher threshold (a hotter signal is needed for compression to occur).

The RATIO Knob Adjusts the overall level of compression. Turn clockwise for a higher (flatter) ratio and ultrasquashed dynamics. Turn counterclockwise for a lower ratio and more subtle compression.

The BLEND Knob Adjusts the wet/dry mix of compression. This BLEND control brings in clean signal as the knob is turned up. 100% wet (compressed) signal is at full counterclockwise on the BLEND knob, and 100% dry is at full clockwise on the knob.

The OUTPUT Knob Adjusts the overall output level (wet/dry mix) of the Atlas and there is plenty of volume on tap.

In the middle of the four knobs is a three-way switch used to select access six different presets. There is the primary bank, and alternate bank. First Preset Bank (Indicated by the green center LED): default the center toggle switch selects between three presets stored in the first bank of presets. Second Preset Bank (Indicated by the red center LED): Pressing the ALT button on the topside of the pedal opens access to the second bank of presets. After pressing the ALT button, the small LED at the top of the pedal’s face will start to blink, indicating that the second preset bank is accessible with the toggle switch. Upon moving the toggle switch the center LED will turn red indicating the current preset is drawn from the second bank.

You are definitely going to want to experiment with all six presets and remember, if you are a bassist, use the Neuro Editor to enable the bass presets. Chances are, you are going to find at least one of those default compression engines much to your liking. I'm a big fan of the Optical engine in the default bank.

But wait, there is still more control using the default knobs and alt mode.

The MAKEUP GAIN (ALT THRESHOLD) dial adjusts the makeup gain within the compression signal. Makeup gain allows you to recover lost output volume caused by heavy compression. The Makeup Gain control only affects your compressed (wet) signal.

TONE (ALT RATIO) Cuts (below noon) or boosts (above noon) the treble control in the parametric equalizer. By default, the Treble frequency is set to about 4461Hz, but this frequency can be changed using the Neuro App or Desktop Editor. That last part is important. If you don't like like the way the tone dial sounds, simply make a change in the editor.

ATTACK (ALT BLEND) Attack controls how quickly in milliseconds compression is applied to your input signal. Turn clockwise for fast attack times and counterclockwise for slower attack times. RELEASE (ALT OUTPUT) Release controls how quickly in milliseconds compression “let’s go” or stops being applied to your input signal. Turn clockwise for fast release times and counterclockwise for slower release times. Again, if you don't like the default parameters, simply edit in the Neuro editor.

From the manual, here's how Source Audio describes the default compression presets: STUDIO: “Studio Snap” - A hard knee VCA style compressor that uses both Peak and RMS detectors to create a dual-stage release and applies a dynamic EQ to enhance attacks. OPTICAL: “Optical Rack” - A gentler and more relaxed compressor based closely on a studio rack mount staple, the LA2A optical compressor. DUAL: “Dual Band” - Based on modern digital processing, this is a two-band compressor that treats frequencies under 333hz differently than those above. This allows for fewer compression artifacts and an enhanced blooming sustain on chords or notes that ring out. STUDIO (ALT): “Studio 76” - Based on the famous 1176, a studio rack mount FET compressor known for its very fast attack times. This version has been optimized for use with guitar. OPTICAL (ALT): “Cubic Zirconia” - A less clean optical compressor based on a popular, discontinued yellow compressor pedal that used an LED to achieve its compression. DUAL (ALT): “Dual Jangle” - A modern style dual band compressor that is aimed at enhancing harmonics above 2000hz, but without adding additional harshness to pick attack. This works very well to enhance 12 string guitars, Jangly strumming patterns, and arpeggiated picking techniques. When set to bass optimization, most of the factory preset are the same name and description with these changes: “Dual Band” has a frequency cutoff point at 82Hz for bass compared to 333hz for guitar. “Dual Jangle” for guitar is named “Dual Lookahead Bass” for bass. It is a modern style dual band compressor that is aimed at evening out string to string balance and maintaining dynamic consistency when switching playing techniques. This mode also uses the Atlas' Lookahead feature. This allows for faster reaction by the compressor without the artifacts usually associated with very fast attack times.

How does it sound?

The Source Audio Atlas Compressor is really like having a black box in which you can dial in whatever you want.

So let's start from the high level. Any adjustment you would want to make to any parameter is there. You can dial in fast and punchy, smooth and fattening and anywhere in between. Want to use as a limiter? No problem. I'm sure many will want to know whether the the Atlas is overly "digital" sounding and not organic. I was very pleased with the tone sweeting benefits of the device. It really sounds great and quite like those devices it is intending to replicate. You've got takes on optical designs as well as VCA and more FET based compression engines. There is something here for anyone. I was able to dial in the likes of the optical Diamond Bass Compressor JR and LA2A. You've got smooth and colored and precise and transparent built in.

The Source Audio Atlas reacts well to whatever you throw at it. If you play a 5 string bass, the ability to adjust how the device responds to lower frequencies is a big plus.

I was part of the beta test group and am really pleased with how this device turned out.

Frankly, if there ever was a one stop shop for a compression device, this might be it.

Why would one not like the Atlas Compressor? I suspect many potential buyers won't want to mess with the editor and others will prefer a true analog device. In a side-by-side comparison to the actual devices the Atlas is intending to mimic I suppose there is nothing like using the real deal. Thats OK. You an get close to the originals though. Close enough for you? Only you can decide. Others might not find it all that intuitive to have primary and alternative modes and all that goes along with that.

I do think Source Audio has done a fine job of cramming in a ton of functionality while maintaining something that has plenty of out-of-the-box brilliance with plenty of deep editing capabilities (if desired).

The Source Audio Atlas Compressor is a compressor pedal I would recommend you try for yourself. It is what the likes of the TC Electronics Spetracomp or Hypergravity only dream of growing up to be. The saying goes that you get what you pay for and with the Atlas, that's a lot of value. There is so much you can do with it. Be sure to visit the Neuro Cloud to see user uploaded patches too.

In my opinion, Source Audio priced this one right too at just $229 (at time of writing). Like all Source Audio products, the Atlas appears to be very well built. For that price you are getting a ton of functionality, not to mention the buffet of compression options. This is a case where I would any perspective buyer to download the Atlas Compressor user manual to learn more about the full product offering.

I do think Source Audio has a hit on their hands and has certainly created something that could be described as a game changer in the current landscape. The sound quality, options, and overall mojo is awesome.

Pros: • Highly versatile

• Multiple compressors in one device • Desktop editor for tweaking and creating new compressors

• Quality

• Useful controls

• Price to value ratio • Gain reduction LED • Something for everyone baked in


• Using the Neuro Editor might be overly complex for some

• While versatile, there is a definite learning curve

• Attempts to mimic popular compressors might not be good enough for purists Retail price: $229 (at time of writing)


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