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DryBell Module 4 Compressor Review

This might be one of the most anticipated reviews I have written in a while. No doubt, the folks at DryBell have a knack for creating unique and inspiring pieces of gear and the Module 4 continues that heritage.

DryBell says the Module 4 Compressor is inspired by the Dan Armstrong Orange Squeezer but moves well beyond with the integration of several unique features. It is not in the scope of this review to describe the Orange Squeezer circuit design but search up "orange squeezer compressor" and you will find plenty of intel. The soundbyte narrative might be that the Dan Armstrong Orange Squeezer compressor design is legendary for its smooth compression and "squashing" tone. The Orange Squeezer was used on many Steely Dan, Doobie Brothers, Dire Straits (Sultans Of Swing), and other classic albums. Dan Armstrong developed a whole series of guitar effects in the 70's — a bunch of little colored boxes that plugged directly into the guitar. The Orange Squeezer was one of them and might be the most legendary of the series.

While the Module 4 certainly has some Orange Squeezer lineage baked in, true to form the engineers at DryBell have also loaded up a bunch of other under-the-hood tweaks, enhancements and flat out useful functionality.

I am definitely a fan of the DryBell Unit67 Rangemaster Compressor. See my review of that fabulous device here. That one surprised me in a good way. I found the Unit67 to be a pretty impressive tone sculpting tool. You can imagine my interest when I first hear rumor of another compressor device from DryBell.

There a lot more functionality than meats the eye in the Module 4.

Let's dive in. On the face of the pedal is six dials, one foot switch and 1 LED and 1 push button LED. The controls are super simple to use and highly useful with a great range across the dials.

There are two modes in which the Module 4 can be used — Orange mode or Full Frequency Range mode. Orange brings the warm, vintage sound while Full Frequency offers up a more modern, brighter, and clearer tone. Either way, you are in for tasty output. To switch between Orange and Full Frequency modes, use the little button located adjacent to the Tone and Blend dials. It lights up orange when in Orange mode. Orange mode definitely has the classic Orange Squeezer feel — more squishy, warmer, and the unique feel that's hard to put into words. When in Orange mode, set each of the dials to align with the black dots which indicate the vintage Orange Squeezer settings. Here's where some of the extra functionality comes to play.

While in Orange Squeezer mode, the dials all still function which means you can move away from the classic Orange Squeezer settings to suit your taste.

Therefore, you benefit from the legacy Orange Squeezer sound and style but you can also dial in slower attack or blend in more of your dry uncompressed signal, for example. Nice! The Preamp dial controls the input gain of the instrument. There is no need to worry about how well this device will work with hot pickups or passive instruments, single coils or humbuckers. By rotating the Preamp dial clockwise you are driving compression stage harder. The dot marks unity gain. The Attack dial controls the reaction time of the compressor by regulating how long it takes the device to latch on and start compressing. If you want more transient or finger/pick attack through, you will want to turn the dial more clockwise for slower attack. The Release dial regulates the amount of time before the unit releases the compressed signal. This is often referred to as sustain. Rotate the dial more clockwise for a longer release time, meaning the compressor holds on to the compressed signal longer resulting in more sustain. The Blend dial allows you to mix the amount of dry (uncompressed) and compressed signals. This is especially useful for bass guitar where you might want more unaffected low end to come through. In my opinion, a competent blend control is one the most useful features on a quality compressor. With guitar, the blend control becomes so useful when you want more pick attack to be heard. This is often referred to as parallel compression. The Tone dial allows you to adjust the overall high frequency spectrum of the pedal. The black dot indicates approximately flat tonal response. Rotate more clockwise for a brighter tone. Whatever DryBell did with the center point of this frequency it works very well for guitar and bass. Perfect for adding a bit more "sparkle" to the sound. The Output dial controls the output volume of the compressor. This is also referred to as make-up gain. As you dial in more compression, you will want to increase the output (rotate the dial more clockwise) to compensate for the decrease in volume. This can increase overall noise but it is not bad here. You can also use the Output control to drive your amp harder as a boost pedal. You get +17db of gain when fully rotated to the right. There is plenty of gain on tap. The LED directly above the foot switch serves a dual purpose. It illuminates when power is applied and the pedal is active. It also serves as a 3-color compression meter giving you a nice visual representation of the gain reduction happening. The LED will illuminate white indicating the pedal is activated. It lights green, then fades to an orange color when moderate compression is occurring. It changes to red when hotter signals are hitting the circuit indicating a lot of compression is taking place.

I am a fan of compressor designs that include LED metering. In general, I prefer multi-led indicators but this 3-color design DryBell implemented works just fine and is one of the better single LED designs I've seen, possibly the best. Really, no complaints here.

OK. Now it is time to open up the hood and look at more of the hidden functionality. Note: I will provide a high level overview of these features. The DryBell Module 4 manual covers each feature in more detail. In every case, the two LED's will provide visual representation of what modes you are adjusting.

Bypass System: The Module 4 can be operated in true or buffered bypass. Hold the Orange button to select true or buffered modes.

Expander: When enabled, the function will automatically attenuate incoming background noise. This can be useful with noisy single coil pickups. Additionally, you can choose between slow or fast expander operation which will adjust how fast the attenuation takes place. The LED above the foot switch will turn turquoise when the Expander mode is activated. Holding the foot switch for 2 seconds puts the device in Expander mode.

Low End Cut:

This features allows you to remove certain low-end frequencies. I am not certain what frequencies it affects but with bass guitar my recommendation is turn off the low end cut. Low End Cut is enabled by default. Tap the foot switch 5X fast to engage or disengage the Low End Cut.

You may be thinking that there's a lot here to dial in and what happens to the settings when you turn off the pedal?

Good news! You can save your settings by pressing the Orange button and foot switch simultaneously.

Here are some initial default settings: • It will be in buffered mode

• Orange mode will be active

• Low End Cut will be active

• Expander will be disabled

• Expander action time will be slow

Adjust from there and then save your settings.

Here's the deal. Many manufacturers claim "pro audio" or "studio quality". There is no doubt that DryBell fits the description.

There is a ton of functional and tone enhancement control built into the Module 4.

You get multiple forms of compression in one pedal board friendly device.

I love the warmth of the Orange Squeezer design but with bass guitar, it can be too much of a good thing. Sometimes, it is too squishy feeling. With the Module 4 in Orange mode DryBell lets you start with that design but tweak it to suit your style. Or you can start with the more modern full frequency circuit and dial in anything you could possibly want in a compressor.

The Module 4 sounds fantastic.

It is quiet, versatile and extremely useful. I can see where some readers might be thinking that all of that functionality comes at a cost — too complex to use. I can see that. Honestly though, DryBell has made it all pretty straight forward. Yes, there is a bit of a learning curve at first, it really does become intuitive. My counsel is to start with the Orange Squeezer circuit and set all dials to the default black dot settings. Play your instrument and then adjust from there. Doing so will give an overview of how each piece of functionality performs and interacts. Then move on to the Full Frequency mode and repeat. Leave the Low End Cut and Expander and bypass functionality for after you have a feel for the two different compression engines. I'm honestly not sure what compression mode I prefer. The Orange mode is inherently warmer but the pristine open feel of the Full Range engine should simply work with whatever instrument you play through it. The Tone control gives you the option to brighten or darken the input. With the Module 4 you can dial in super warm and squishy compression or light, airy, and sparkly compression. This would be the engine to select for more of that "tone mojo" we often talk about. The nod to the Dan Armstrong legacy is there but then you have the Full Frequency mode which is quite neutral and transparent by default. There is something here for everyone.

I had no issue with headroom with any of my basses or guitars and noticed no distortion at any point in my testing.

Compared to the DryBell Unit67, the Module 4 is by far the more versatile compressor. That is certainly what the Module 4 was designed for. On the other hand, the Unit67 is an impressive tone sculpting tool with competent compression engine.

Power and input and output jacks are top mounted. The pedal has a solid feel to it exudes quality. The dials turn with solid resistance and the foot switch is the quiet soft-switch type. Power requirements are 9-18 volt center negative plug with minimum 100ma. I think the pedal design looks killer — the proprietary design moves well beyond the run-of-the-mill standard enclosures used by the masses.

True to form, the packaging DryBell uses is an experience in and of itself. The outer box showcases DryBell branding and then a sealed inner DryBell branded box contains the Module 4. There is also a leather keychain to hold picks and a user guide. Again, everything about DryBell oozes quality.

Something unique to the DryBell brand is how they display general usability settings on the bottom of the pedals. I think that's a nice touch.

DryBell offers a 2-year warranty which is beyond many pedal manufacturers.

Check out this link to learn more about the team behind the Module 4 and how it came to be. It's an interesting read. With the Module 4, you are getting a lot for you money. It's amazing how much greatness the folks at DryBell have crammed in to a single pedal. There is a lot to like. As a compressor, it's going to do pretty much whatever you need it to do, and then some. It is very well thought out and implemented.


• Versatility

• Tone enhancement • Sustain

• Two compression engines in one pedal

• Quality

• Design

• Huge bang for the buck


• Possibly too much functionality for some • Price, but you do get a lot for the cost of admission


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