Rat II
ProCo Rat II. This is today what is sold by ProCo as "The Rat". It's a chinese-made pedal and no longer uses the LM308 opamp integrated circuit (IC). This is a very common pedal as it has a good sound and because of its chinese manufacture is available for a moderate price.
- Thermionic Studios has one(1) ProCo Rat II available for rental
Controls
- Knob 1 - "Distortion": Adjusts the level or amount of Distortion with fully clockwise being maximum.
- Knob 2 - "Filter": This knob is a tone control that is a bit of a fluke. Unlike just about every other tone control on an amplifier, or a pedal, turning the knob fully clockwise ends up rolling OFF the high frequencies.
- Knob 3 - "Volume": Adjusts the output level with fully clockwise being maximum.
- Footswitch 1 - "On/Off": This footswitch toggles the pedal between engaged/active ("On"), and bypassed ("Off")
Bypass: True
The ProCo Rat II is true bypass. The one thing that's interesting about the true-bypass nature of the Rat is that it doesn't use a 3PDT (triple-pole dual-throw) switch, it uses a DPDT (dual-pole dual-throw) switch while at the same time entertaining the feature of an LED. Most pedals have a 3PDT where one of the set of poles in the switch handles the current flow to the LED indicator. The folks at ProCo, when they looked to compete on adding an LED indicator still had a huge stock of DPDT switches. ProCo handled the new requirement by continuing to use their stock of DPDT switches, but engineered a solution where the only had to an additional transistor and a couple of diodes so as to be able to add that LED without losing the true bypass switch.
The cost of an extra transistor and two diodes is far less than a whole brand new 3PDT switch.
It's a very clever arrangement you can read about here.
General Information
From http://www.freestompboxes.org/viewtopic.php?f=1&t=13679 :
People say that the OPO7 is thinner or harsher sounding than a LM308. I think, however, that this perception may be down to the fact that a lot of the Chinese Rats have 0.0027uf instead of a 0.0033uf cap in the tone control. This will make a OPO7 Rat sound brighter at the same tone settings compared to a LM308 Rat.
If you bump the compensation cap of a OPO7 up from 33pf to a 100-150pf to compensate for the fact that the OPO7 has a faster slew rate than a LM308 then they sound pretty much the same to me.
Pedal Manual
Phase Inversion: Yes/No
Schematic
Artists
We are currently unaware of any artists actively using the pedal now, or who have in the past.
- Additional Sources
