I've been playing with this pedal for a few days now, soaking it all in. It is a very unique pedal.
On a spectrum of super transparent to totally colored, the Photon falls on the more colored side of center. But this is not a negative. The Doc Lloyd sounds fantastic. I'm not sure what all is going on with the "human ear sidechain" but it works to retain the low end. It does it in a way that isn't muddy, but not "tightened" either. It's flat out big. With my Beyerdynamic DT770 earphones I hear a "wider" low end than any of the compressors I've tested to date. The mids are punchy as all get out while the highs are open but compressed.
In many ways, it reminds me of the Diamond in that it adds something special in the form of bigness and spacial widening.
I used it at 9 volts and 18 volts and to my ear I hear a little more grunt and raw sound at 9 volts and so I prefer it at 9 volts. I don't think my ear is tricking me either. Maybe some sort of sag effect or something going on but I like it at 9 volts. It isn't distorted, in fact there is plenty of headroom unlike the Diamond. It is more of a grunt or midrange presence that feel really, really punchy.
The compression itself is pretty limited though more range than the Diamond. With my active basses I like the threshold switch in the center position. With the compressor knob at 2:00 - 3:00 the orange led lights periodically indicating over threshold. My unscientific view is that it is compressing the D and G string notes more than the B, E, and A string notes. The mix knob provides a lot of tonal variety. The controls are pretty simple and you pretty much just mess with the mix and compression knobs. The threshold LED is the one in the cannon graphic. It's OK... has nothing on the Darkglass or Empress LEDs though. It doesn't really seem all that responsive. Definitely not compared to the Empress.
Compared to the Empress, it isn't as neutral or uncolored. But the low end is bigger than the Empress.
Compared to the Cali76 CB, both do a great job with the low end assuming you have the HPF near or all the way clockwise. But the Doc Lloyd is just "bigger" and "more spacial" than the Cali. The Cali probably has the more "open" feel but it isn't as "big" sounding as the Doc Lloyd.
The Smoothie can be pretty big sounding too, but its not as "punchy" as the Doc Lloyd. Turning the tone knob counter clockwise on the Smoothie brings more low end, but again, the Doc Lloyd does more to the low end in a "spacially wide" sort of way. Hard to describe.
IMHO the Doc Lloyd isn't for people who want a truly neutral, transparent pedal or a "tight" low end compressor.
But if you want some tone magic and "bigness" I'm really impressed. It definitely has an inherent flavor. Words like "punch", "grunt", "big", "wide", and "mid forward" come to mind. It's also not for people who want a highly versatile compressor or those who want control over attack, threshold, input, output, etc. I never really felt like I wanted to adjust the attack and threshold though. It just works. I'm going to ask russ at Doc Lloyd more about the sidechain.
The pedal seems very well made and though the art isn't necessarily my thing, the paint job is stunning. Top mounted jacks.
I'll update this posting with more comments in the future. Wanted to get something out there for those of you really wanting the skinny on this pedal. It's very, very cool. I can see this being an always on "tone magic" compressor. All for now.
Retail Price: $199
Further Update: A couple people have messaged me asking for more information about the tone of the Doc Lloyd. It is not mid-heavy in a clanky sort of way. It is mid-heavy in a punchy, rich sort of way. More in the low mids I think. It's a very musical compressor. I don't know how to say it other than it is just very big and rich but not wooly with highs rolled off. It adds a little something special that is bigger. You will feel your tone is more "there". Not necessarily louder, just more there.