The Empress compressor is definitely more on the transparent side of things.
If you are interested in the Keeley Bassist but want more control, this would be one I'd seriously consider. That being said, it takes time to dial in and figure out exactly how you want to set it. I found myself constantly tweaking the knobs to see what small changes would do to tone. Good news is, a lot of control. Bad news is, I think I could go crazy constantly tweaking.
Sometimes a little goes a long way — especially with the output and input knobs. From all compressors I've tested so far, the Keeley and Empress are closest together in the neutral tone category. Cali, FEA, and Duncan Studio Bass all add a little something to the tone. Smoothie too, though the tone knob does provide a lot of tonal variety purposefully.
The physical size is smaller than I expected but still of a form factor that will preclude it from some people's pedal boards. Top mounted jacks would be preferred. I included a picture with the Smoothie and Cali to show size.
The LED's are simply amazing. I've had a MXR M87 in the past but these LED's on the Empress are just flat out better.
They look better and the ability to display both the gain reduction and input hitting the compressor. Red LEDs communicate indicate gain reduction. Green LEDs indicate input volume. You can have both on together and they turn yellow where they merge. Very cool and super helpful in understanding what the compressor is doing.
I wan't sure I was going to like the three-way switch for ratio control but it works just fine. You can easily perceive the differences in each position. I need more time with the 10:1 ratio to see what it is really capable of. I like the 4:1 setting best. Just seems like a real nice amount of compression, yet remains open and punchy. Really nice actually.
The Empress seems to hold on to the original amount of bass and high end of my instruments. I don't feel like it really bolsters the low end.
If you are looking to make the bottom end sound bigger (fatter) this isn't the best option. Everything tightens up.
I guess that's how I'd describe it. To my ear anyway, it isn't adding "umph" its adding more presence. There is certainly plenty of gain available (tons actually) so you can make your signal hotter easily. But that's not really "bigger". For example, the HPF on the Cali lets a little more bass through. The sidechain knobs on the FEA allow you to dial in the compressor to perceive more low end.
If you want a compressor that sounds absolutely fantastic but doesn't alter your tone a whole lot and provide a lot of flexibility, this is a strong contender.
When I listen to the Empress beside the Smoothie, to my ear I can see how the Smoothie is really adding a little color to the tone. The Empress pretty much sounds like my basses, just more present and, well, sounding better. I really like how it reacts to a wide variety of playing styles.
Build quality seems great. The pedal is nice and light too. Especially compared to the Cali.
The Empress has side chain operability with the jack on the side though I haven't tested that yet.
One thing I found really interesting is that the Empress is the first compressor that I like using with all of my basses. From my Sire P7 to my G&L L2500 to my pre-Gibson Tobias to my fretless Pedulla Pentabuzz. Not sure it would necessarily be my first choice necessarily but it just works.
One more thing. If you are unsure of how compressors really work and want to understand and build your ear for what a compressor can do, I think the Empress would be a great option. The LEDs really help and I like having control over attack and release separately. I'm also a big fan of the dry mix.
Here's a link to the manual if you are looking for more explanation of how each control functions.
Retail price: $249