Dating a proco rat
The Pro Co Rat is a distortion pedal by Pro Co Sound designed by Scott Burnham and Steve Kiraly in Kalamazoo, Michigan 1978.The original circuit and appearance suffered some changes over the different revisions but the tone remained the same.Could anyone segial me determine whether any of that was accurate? Pro Co Sound FATRAT Distortion Pedal with Selectable MOSFET Clipping and Thick Boost Distortion. Harmonics below 1.5 KHz and 60Hz are attenuated due to the high-pass filters.In high frequencies there is also a roll-off because of the low pass filter and the op-amp gain-bandwidth product, both effects more noticeable at high-gain (blue lines).This filtering provoke that bass notes will be attenuated before the clipping action, making the low end less clipped and creating a The original Rat pedal uses the LM308N Motorola op-amp, the Texas Instruments OP07DP was a replacement op-amp used in the new models.Part of the Rat's tone remains on the choice of the chip as a function of the Slew Rate, the Gain-Bandwidth Product, and the Compensation Capacitor: In the image above, the slew rate of the LM308 is shown together with the TL071 (standard op-amp used in stompboxes) for comparison purposes.
This original signal will be amplified by the op-amp until the power supply limits (line represented in purple).Gilmourish has an excellent piece about the RAT and explains why it is a good staple distortion pedal.IMPORTANT: Treat everyone here with respect, no matter how difficult! The Turbo RAT distortion pedal is for the guitarist who would rather create their own sound than emulate someone else's. It is usual to find a combination of low pass and high pass filters before or within the clipping stage in distortion pedals.The distortion makes the original guitar signal more harmonically complex, this means that more amounts of distortion are being added, it can be more difficult to give each sound its own space in the band mix.