1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  

Vintage ProCo RAT mini-Restoration Thread

Discussion in 'Effects [BG]' started by Armchair Bronco, Mar 28, 2009.


  1. Here's a mini-Restoration thread I've been posting here and there of a vintage ProCo RAT I recently purchased. The RAT was one of the "bassline" pedals that defined Nirvana's tone in the early days. It was Novoselic's favorite pedal by a mile, and Cobain also used one in addition to his trusty DS-1.

    ***

    Last week, I purchased an early 1980's vintage ProCo RAT from someone at work. Here it is:

    [​IMG]

    This is a low serial number ProCo "The Rat" and I originally thought it was from 1983 or so:

    [​IMG]

    More than 25 years ago, the original owner disconnected the internal 9-volt input jack, carefully bent it out of the way, and installed in its place a Radio Shack "Battery Eliminator" wall adapter.

    [​IMG]

    He fed the adapter wire through the jack opening, re-soldered it together, and connected it to the 9-volt battery connector. He then used duct tape to seal up all the original parts. Nice work for a 17 or 18 year old to take the time to keep all of the original parts around.

    [​IMG]

    I used small scissors to cut away the crumbly, sticky duct tape to expose the original components. Here the battery clip cover has popped off. I cleaned off the goo with some lighter fluid and re-attached it to the 9-volt connector.

    [​IMG]

    Then it was time to "cut the umbilical cord".

    [​IMG]

    Next, I took the duct tape off the original power jack. Yay! All the original hardware was still there. It was bent up to move it away from the jack opening, so I'd have to bend it back down.

    [​IMG]

    Now I was able to get a good look at the pots. If I'm not mistaken 7-digit number 1378150 on the pots means the following:

    137 = CTS
    81 = Year
    50 = Week

    So the pots at least were made during December of 1981. I was a freshman at the University of Colorado at Boulder then.

    [​IMG]

    I removed the 2 input jacks and then carefully coaxed the power jack back into alignment. When everything was lined up correctly, I re-installed all 3 jacks and tightened up the hex nuts.

    [​IMG]

    Here's the exterior of the "restored" RAT.

    [​IMG]
     
  2. And here's the graduation photo, with the RAT back on a pedalboard after sleeping in a box for more than 2 decades. Have I said yet that it sounds killer? No? Well, it sounds killer!

    (I know I've posted this elsewhere, but it's important to have the pedalboard shot in this thread as proof that this vintage pedal is back in action.)

    [​IMG]
     
  3. how much bass loss is there?
     
  4. Well, the "word on the street" is that in general you lose a lot of low end with the RAT. A lot of bassists seem to prefer the Turbo RAT.

    In my case, I use this primarily with my guitars. My only bass is an SX short-scale bass, so it doesn't have much low end to begin with.

    I did notice that the RAT really accentuated the scratchiness of the cheap pots on the SX bass. The distortion didn't sound very good through my Roland Cube 30 bass amp (no surpirse there), but I still haven't tried it through my Ampeg BA-112. I'll bet it would sound a lot better through a cleaner bass amp like the 112.
     
  5. i have a vintage RI Rat that i modded, as well as a Turbo Rat. Turbo does sound better for bass, but both roll of the lows quite a bit. Rats for guitar is where it is at tho. Looks killer!
     
  6. toni_2x

    toni_2x

    Jun 3, 2011
    photo of the transistor? what brand?
     
  7. dune2k

    dune2k

    Sep 26, 2009
    Germany
    IC is a LM308N, you can see it on one of the pictures.
     
  8. rratajski

    rratajski Commercial User

    Jul 1, 2008
    Mount Laurel, NJ
    Builder for FUZZROCIOUS PEDALS
    That's not a transistor though ;).
     
  9. dune2k

    dune2k

    Sep 26, 2009
    Germany
    True. Should have written that I guess that he/she's asking for the OpAmp. ;)
    Transistors, in this case JFETs, should be BF245A. Though different ones (2N5457/2N5458 or maybe a MPF102) here shouldn't make that much of a difference since they are only there for buffering (the first one) and a fixed volume boost/lowering of the output impedance.

    /Edit: For those interested in Rats: Try a LM301 in there. They are basically the same as the LM308N but muuuuch cheaper (something like 0.40€ compared to around 3.5€). I couldn't hear a difference between the two in my Rat.
     
  10. toni_2x

    toni_2x

    Jun 3, 2011
    is there any photo of the actual transistor?
     
  11. rratajski

    rratajski Commercial User

    Jul 1, 2008
    Mount Laurel, NJ
    Builder for FUZZROCIOUS PEDALS
    I hear a slight gain difference b/w the two opamps. I use the 308 in my Rat Tail and the 301 in my Dark Driving.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.