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Whirlwind OC Bass Optical Compressor Review

With the OC Bass you get both a transparent compressor and limiter depending on how you have it switched. It is definitely a neutral sounding compressor but maybe not 100% transparent along the lines of the Keeley Bassist or Empress. There is some subtle "juicing" of the tone. Don't think Diamond, Doc Lloyd Photon, or Pulp 'N Peel, just a subtle "bigger" feel. It's pretty subtle though.



There is plenty of headroom. I had no issue using the pedal with any of my basses and I was impressed with the very low noise floor.

In many respects, the OC Bass is a simple to operate compressor with only two knobs and two switches. • The Level knob controls the overall output level of the pedal. • The Input Gain controls how much compression (or limiting) is applied to the sign. The overall volume will dramatically increase/decrease as you rotate the Gain control though so you will need to use the Level knob to compensate. The amount of compression has a nice range and is noticeable and smooth across the range. • The 3-way Attack switch allows you to set the speed at which the compressor latches on to notes. Fast is almost instantaneous and is pretty grabby. Medium allows a little transient through and Slow delays even more before the compressor latches on. Slow and Medium positions were very nice; the Fast was much to grabby for my taste. • The Compressor/Limiter switch puts the pedal in either mod. The Compressor is nice and smooth and does a fantastic job of evening things out. The Limiter also works very well and has a pretty extreme range. In limiter mode I found I did not need to turn the Gain knob past 9:00 or so before the limiter effect really took away to much in the way of dynamics.


The Gain Reduction LED's displays the amount of limiting/compression in dBs and is a very nice feature to understand what the compressor is doing. There are only three LED's marking 3db, 9db, 15db so quite limited in feedback compared to the Darkglass Hyper Luminal, MXR M87, or Empress.

I compared the OC Bass with the Hyper Luminal, FEA DB-CL, Amptweaker PressuRizer, Ampeg Opto Comp, and Diamond Bass JR. The OC Bass is transparent and has a very natural feel to it. There is noticeably less color than either the Diamond or Ampeg. It felt and sounded most like the PressuRizer though the PressuRizer with the Bloom feature activated will sound bigger than the OC Bass. The Hyper Luminal in BUS mode sounds similar to the OC Bass. Both the Hyper Luminal and FEA offer far more control. The FEA and OC Bass both offer nice clean and tight compression. You can configure the FEA to sound bigger in the lows though. This is also true of the Hyper Luminal when you use the software suite to adjust the HPF. But the OC Bass doesn't seem to lose the low end either. It retains the hight end well too.

One of the more subjective aspects of the OC Bass is how it feels — the response when playing. To me it just feels responsive and very natural. It's not neutral in the sense that it is boring. No, you notice it when you turn it off and immediately miss it. But its not like an EQ where you notice the different frequencies missing when you turn off an EQ pedal. This is just a real nice compressor doing its job real well.

On the downside though, the Gain knob beyond noon is just too grabby for me.

You get that "twack" or "thump" at the initial transient otherwise which is much more noticeable past noon. With the Attack switch in Fast that transient squish is much more noticeable.


The Whirlwind OC Bass is not a small pedal, but it is not as large as it might appear in photos. It is very similar in size to the FEA pedals or original Diamond BCP-1 pedal, though it is taller and considerably heavier than either. It is built like a tank. A red LED lights when the pedal is activated by a click less type true bypass foot switch. It is powered by 18 volts and requires just 60ma. Top mounted jacks.


If you want a nice overall smooth, relatively neutral compressor with no dip and swell activity, this Whirlwind OC Bass is pretty impressive. It just sounds and feels great and is a quality piece. It is also very low noise. I suspect some will gravitate toward this one for its enclosure design too with high sides making it hard to accidentally adjust the knobs or switches.

The pedal is hand made in the USA.

A very special thanks to the Talkbass.com member who sent this to me to review.


Retail price: $242





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