Proco Rat

from wikipedia:

The Pro Co "The RAT" is a distortion pedal with a very simple circuit, based around a single op-amp, the LM308. The distortion is produced using a variable gain circuit with diodes shorting the output to ground to produce hard clipping of the input waveform. This distortion stage is followed by a passive tone filter and volume control. This is the same scheme as the Boss DS-1 distortion pedal, although there are major differences between the two circuits, therefore the sound of the two pedals are different. The most popular RAT pedal, the RAT2, features true-bypass switching.



I love this pedal I have the vintage LM308 and it sounds dirty and mean and thats why I love it.
Now its a two trick pony in my book , a lite crunch lower distortion semi-clean sound at the left of the dial and at the right half grinding mid range for miles.

Now its not the most nuanced tone but when you know you want what it does it sounds great.

I think the newer version are pretty good Ive tried them out and they are not that different, well they are a bit different but some of the new models are intended to be other things to people.

The vintage pedal has a particular sound we have heard on many records over the years and its not a silver bullet it could be totally wrong for a given song but I like it when I do.

I \know some people do mods to these to open up the options I have not gone down that road I dont have that much time for tech work, but Im sure many here have and I bet its cool

Stock its a very satisfying 2 trick pony.