Difference between revisions of "Rat II"

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[[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.
+
[[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 relatively moderate price.
  
 
* '''Thermionic Studios has one(1) ProCo Rat II available for rental'''
 
* '''Thermionic Studios has one(1) ProCo Rat II available for rental'''
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==Bypass: True==
 
==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 ProCo Rat II is true bypass by a means you may not have seen before.
 +
 
 +
It's called the '''Rat 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 that is also able to entertain 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 with other pedals, by 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.
 
The cost of an extra transistor and two diodes is far less than a whole brand new 3PDT switch.
  
−
[http://www.muzique.com/lab/true_bypass.htm It's a very clever arrangement you can read about here].  
+
[http://www.muzique.com/lab/true_bypass.htm It's a very clever arrangement you can read about here]. Another interesting note about the Rat Bypass is that it prevents the effect from "popping" when you
 +
 
 +
R. G. Keen takes the Rat Bypass a bit of sophistication further and [http://www.geofex.com/Article_Folders/Millenium/millen.htm offers the Millenium Bypass] for those who are interested.
  
 
==General Information==
 
==General Information==
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</div>
 
</div>
 
</blockquote>
 
</blockquote>
 +
 +
===Modifications===
 +
The newest chinese Rat II pedals have everything, including the potentiometers, mounted to the circuit board making modifications to them difficult, if not impossible. Many have suggested the [[You Dirty Rat]] as an alternative as it is still manufactured in the US (as of this writing) and because it maintains the higher-quality componentry and PCB-tracing, it is a better candidate if you're looking to modify your own Rat II. It's still possible to do this on Rat II pedals, but you're going to have to look for an older model that maintains the higher quality.
 +
 +
The only difference between the Rat II and the You Dirty Rat parts specifications are the clipping diodes. (Monte Allums, linked below)
  
 
==Pedal Manual==
 
==Pedal Manual==
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==Artists==
 
==Artists==
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We are currently unaware of any artists actively using the pedal now, or who have in the past.
 
 
<div style="column-count:3;-moz-column-count:3;-webkit-column-count:3">
 
<div style="column-count:3;-moz-column-count:3;-webkit-column-count:3">
 +
* Jeff Beck
 +
* Nuno Bettencourt
 +
* Jerry Cantrell
 +
* Justin Chancellor
 +
* John Christ
 +
* Kurt Cobain
 +
* David Gilmour
 +
* Dave Grohl
 +
* James Hetfield
 +
* George Lynch
 +
* Buzz Osborne
 +
* Kevin Shields
 +
* Andy Summers
 +
* Joe Walsh
 
</div>
 
</div>
  
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;Additional Sources
 
;Additional Sources
 
* https://www.electrosmash.com/proco-rat
 
* https://www.electrosmash.com/proco-rat
−
* http://www.muzique.com/lab/true_bypass.htm
+
* http://www.muzique.com/lab/true_bypass.htm - Explanation of ProCo Rat True Bypass
 +
* http://www.geofex.com/Article_Folders/Millenium/millen.htm - Full explanation of Millenium Bypass
 +
* http://monteallums.com/pedal_mods_Proco.html
  
  

Revision as of 22:04, 17 March 2019

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 relatively moderate price.

  • Thermionic Studios has one(1) ProCo Rat II available for rental

Controls

Image from Sweetwater
  • 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 by a means you may not have seen before.

It's called the Rat 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 that is also able to entertain 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 with other pedals, by 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. Another interesting note about the Rat Bypass is that it prevents the effect from "popping" when you

R. G. Keen takes the Rat Bypass a bit of sophistication further and offers the Millenium Bypass for those who are interested.

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.

Modifications

The newest chinese Rat II pedals have everything, including the potentiometers, mounted to the circuit board making modifications to them difficult, if not impossible. Many have suggested the You Dirty Rat as an alternative as it is still manufactured in the US (as of this writing) and because it maintains the higher-quality componentry and PCB-tracing, it is a better candidate if you're looking to modify your own Rat II. It's still possible to do this on Rat II pedals, but you're going to have to look for an older model that maintains the higher quality.

The only difference between the Rat II and the You Dirty Rat parts specifications are the clipping diodes. (Monte Allums, linked below)

Pedal Manual

Phase Inversion: Yes/No

Schematic

Artists

  • Jeff Beck
  • Nuno Bettencourt
  • Jerry Cantrell
  • Justin Chancellor
  • John Christ
  • Kurt Cobain
  • David Gilmour
  • Dave Grohl
  • James Hetfield
  • George Lynch
  • Buzz Osborne
  • Kevin Shields
  • Andy Summers
  • Joe Walsh
Additional Sources
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