Source circuit:     ProCO RAT 
                   Style:     distortion 
                    Built:     19 November 1996 
Source Schematic:   ProCO RAT (Gif format, 10KB) 

Comments:  

In late '96 I had a good TS-9 overdrive and wanted a good distortion pedal. I read good things on the 'net about the Rat and located the schematic at Leper's archive (actually, these first three schems came from there...if you were into effects and had 'net access back then, you know about Leper!).  

This was the most elaborate by far because I designed a PCB (printed circuit board) using an old DOS-based board layout program. I laser printed the result onto clear overhead stock and used a pre coated circuit board. I went through the photo and etch process and ended up with a good looking board. All chemicals plus the board and other material (including UV light tube) came from a local electronics shop. Finally, I used a Dremel tool to drill the mounting holes and installed the components. 

I wasn't satisfied with the stock clipping diodes (once again), and used a slightly different arrangement. The switch on the top side selects between these two diode arrangements:  

   (1) silicon + silicon (in parallel) 
   (2) silicon + red LED (in parallel) 

Version (1) is smoother and more "vintage" sounding while (2) is more aggressive. This pedal is capable of copious amounts of distortion and sounds great with single coils and humbuckers through all my amps. With the gain (BITE) way down and level way up on setting (1) it provides a great Overdrive tone as well. Excellent tone! 

Versatile pedal and was by far the favourite of my home-built pedals until I built the Skildrive. Once again, label in Excel, 1590BB Hammond box, Carling DPDT foot switch, and auto lacquer. No LED and true bypass switching.