Dedalo Gorila: This handmade optical pedal comes to us from Argentina. In Spanish gorilla is spelled with only one "L". It's called a bass compressor, but it will work equally well with guitars.
The tone is warm but clear; not "perfectly transparent", but clean. There is very little noise. There is no loss of highs or lows, although the tilting EQ (tone) knob affects that. When you turn the tone knob to the left, it boosts the lows, while the highs stay mostly flat. When you turn it to the right, it cuts the lows and boosts the highs. At 12:00, the most "flat" position, it is truly flat down to around 50 Hz, where it starts to gently roll off, and 30 Hz is about 2 dB down (not much). This EQ is deceptively simple--it achieves a range of very useful results, considering it only has one knob.
The "compression" knob is a threshold control, with a very wide range, so it responds well to both low-output and high-output instruments. It doesn't distort unpleasantly even when feeding it a very hot input signal. The ratio is fixed at 5:1, a "medium" amount. So you can get peak limiting and heavy compression by lowering the threshold (turning the compression knob clockwise), or use it more subtly just by raising the threshold. There is a nice big LED that indicates the amount of your signal over the threshold. I like to set it so the light only flashes about 1/4 to 1/3 of the time that I'm playing, but for more sustain you'd want the light on more of the time. The attack control also has a wide range, so you can go from instant peak grabbing (with a fast attack) to gentle and unobtrusive sustain (with a slow attack), and the LED helps you see this as well.
Because you have to set the threshold low to get strong compression, the resulting action may sound too noticeable or "effect-y" for some people. It can have a bit of dip and swell. This is not inherently a bad thing at all--but for a person who wants total transparency, it might be too much. Naturally though, the higher the threshold, the less noticeable that effect is.
The construction quality is very good, and the footswitch is "true bypass". The size is slightly bigger than a Boss, slightly smaller than a Diamond or Barber. It runs on standard Boss-type 9VDC.
There are many optical pedals on the market, so here are some comparisons:
The Diamond has a purer, more transparent tone and action, but its ratio is lower and its indicator LED is not as easy to read as the Gorila's.
The Demeter is smaller, the BBE Optostomp is cheaper, and the BYOC Opto is both smaller and cheaper; however none of them handles a wide range of input levels as well as the Gorila, and none have a threshold indicator light or an attack control.
The FEA OptiFET is better-sounding and more versatile but it costs twice as much.
All in all the Gorila is a really great pedal, I like it a lot!