This review is for the version intended for Bass guitar. It is an option that can be selected by ordering direct from Strymon for an additional $30. The standard OB.1 is designed to start rolling off bass frequencies at about 80Hz. However, the bass modification is available without this filtering to expand the low end range. To my ear, the bass version I tested retains the low end and doesn't seem to alter the high end in any significant way either.
Clear, transparent, and neutral would be three key words I would use to describe the Strymon.
It is limited in control having just an output knob and compression knob for the compressor side of the pedal.
The bass optimized version of the Strymon OB.1 is marked with a sticker on the inside of the enclosure and a sticker on the outside of the box.
The Output knob controls the overall output level. Attenuation is possible at low settings as well as overall boost at higher settings. There is plenty of volume on tap.
The Comp knob sets the threshold of the optical compressor circuit. It seems to have a wide range offering light compression all the way counter clockwise to quite heavy all the way clockwise. Strymon doesn't include the range in the manual but all the way clockwise gets fairly squishy. I found the entire range to be very natural and usable up to all but extreme settings. Turning the Comp knob all the way counter clockwise effectively takes the compressor out of circuit. I don't think this would be the best choice to use as a limiter, but for light compression, evening out of tone, to fairly aggressive smooth compression it is great.
There is also a clean boost feature which is activated by a second foot switch. It is important to note that the boost circuit is only selectable when the compressor is on. In other words, you can't use the boost separately from the compressor. I'm sure Strymon has a reason for this but I would prefer being able to independently use the boost. It would make the pedal that much more versatile. That being said, it works well and has plenty of boost on hand. The amount of boost is controlled by the Boost Level knob and offers an additional 10dB of gain. Turn fully clockwise to engage a little soft clipping. It's a nice feature to have when you want a little extra umph and could potentially allow you to remove one pedal from your board and take care of compression and clean boost with just the OB.1. That is as long as you are OK with post compression boost. The 3-way switch allows for boost of only the highs, only the mids, or the full-range signal. Inside the pedal are two dip switches that can be set to alter the frequency response of of the treble and mid boost functions. By default both dip switches are in the downward off position. Switching the left switch on (up position) lowers the treble boost corner frequency. Switching the right switch on (up position) for a lower mid boost peak frequency. Mid Boost Frequency: Peak around 800 Hz or 1.1kHz switchable with internal DIP switch.Treble Boost Frequency: Shelf at about 1.5 kHz or 2kHz switchable with internal DIP switch.
Honestly, regardless of the positioning of the dip switches the treble or mid boost selection would be better suited and tuned for guitar.
But in flat, the boost sounds great. It is clean, transparent and simply delivers more volume. I used the OB.1 live more than once and used the OB.1 always on and also leveraged the boost to pop out a bit more on choruses and bigger moments. The boost doesn't add more compression.
A red LED lights when the pedal is activated (the right foot switch). The choice of the word Bypass might be a bit confusing at first since the LED under the word bypass lights when the compressor is active not bypassed. The right foot switch activates the boost circuit with a red LED indicating the boost is active.
The OB.1 is an optical circuit and is a very smooth and musical compressor. While it is not the most versatile compressor ever the added boost feature is real nice. In my opinion this is an ideal selection for an always on compression when low to medium compression is desired. It doesn't color your tone but somehow makes the bass sit real well in a mix. It has an inherent smoothness that sounds great and feels great. It is very quiet, pretty much across the entire compression range. It is a simple-to-use, no nonsense compressor that sounds very nice. It isn't some sort of "tone magic" device but offers a sweet musical flavor of compression in a subtle but helpful way.
The foot switch is true bypass electromechanical relay switching. Top mounted input and output jacks as well as 9 volt input.
The casing is brushed aluminum and is very solid. The whole pedal looks and feels like a quality piece of equipment all the way around. It is very similar in size to the original Diamond compressor pedal but is taller (top to bottom). Due to the top mounted jacks, the Strymon OB.1 is pedal board friendly.
Retail price: $199; with bass modification $229