pi
Tele-Meister
I don't exactly understand the circuit, but the Timmy is a great always on kinda pedal. There are others. I really like the Greer Lightspeed. A clon with the gain low is another. The problem with playing a clean amp clean is the lack of transients and sustain. A Timmy or any transparent overdrive helps this.
I really like the Lightspeed as well, slightly more than the Timmy--circuit-wise they are quite similar. With the Lightspeed, you have less control over the tone, which might be a concern for some, but the Lightspeed is dialed in just right and I don't miss the bass knob.