Reporting in on the Greenhouse: I've had the chance to use it a few times this week. It definitely adds some lovely character to my dry tone. I've become very used to the tone/feel of my p bass with Daddario flats, directly into a Radial JDI over the last few years, which I would describe as 'pure', 'woody', almost quite acoustic sounding. When I first plugged into the Greenhouse, I found it to be very similar, but over the week it's different characteristics have become more clear.
I used it on a recording session at a friend's home studio on Thursday night. In the end we went back to just the JDI as the setup was introducing some quiet high frequency hiss/whine (definitely a result of my very cheap power supply in the mix with a lot of other devices - I have a 1spot on the way). On good studio speakers the difference between the two setups was more clear, rather than being woody, clear and thumpy, the Greenhouse imparted a lovely warmth and slight woolliness/softness to the sound. Compared to the JDI, it loses it's acoustic feeling in favour of a slightly more amped-up feel, most obvious on very low and very high notes, which both gain a bit of roundness. Of course it's not just a case of eq - the tone changes throughout the entire frequency spectrum, and all these changes are very subtle, the overall tone remains very very clean and defined. You're losing some minute detail in order to add depth/air.
These differences were again confirmed tonight when I put it through it's paces as my sole pedal, running into the JDI at a gig. I borrowed a spare power supply/plug from the guitarist, and had no problems with hiss. At high volumes, the Greenhouse felt thick, creamy, fat etc. but still perfectly suited to accompany an acoustic guitar.
I still need to do a lot of playing with it before I add other pedals to the mix. For example, I've found that the tube is very sensitive to the buffer in a Boss TU2. Putting the tuner before, in the the loop, or after the Greenhouse all had a surprisingly large affect on volume, as well as tone. I had a great time putting a student's cheap Behringer OD3 distortion/overdrive pedal in the loop. My bass and guitar both went from very plastic to pretty expensive sounding in the loop! It completely transformed that pedal.
Overall i'm a very happy customer. As long as the 1spot can help eliminate that cheap power supply hiss then i can see myself permanently keeping the Greenhouse on my board as an essential always-on tone sweetener and level set. It complements the JDI very very well. I never felt my tone was sterile before, but I'd happily recommend this pedal to anyone in that position.