GFS Brownie/Biyang Mouse users - IMPORTANT (Rat content)

Discussion in 'The Stomp Box' started by 11 Gauge, Jan 3, 2012.

  1. 11 Gauge

    11 Gauge Doctor of Teleocity

    Posts:
    10,862
    Joined:
    Mar 21, 2003
    Location:
    Near BWI Int'l
    I think they are all fine as long as you can mostly stay stock and just add switches for the diodes, a 4th knob if it has the Ruetz thing, and so on.

    I have been using the GGG Rat board, but I need to switch. It is just a tad too wide for the smallest MXR sized boxes, and they changed the output buffer biasing so that it is more sophisticated than just running at unity gain.

    ...So because of the GG change to the output buffer thing, you may actually want to go with the Slow Loris, or the Tonepad s/b fine, too. I think I built one of the Tonepad ones some time ago.
     
  2. bigp7099

    bigp7099 Tele-Holic

    Posts:
    884
    Joined:
    Oct 1, 2010
    Location:
    Brampton, ON
    ok thanks, the tonepad version seems bog standard, the loris has a switch for clipping choices and a "sweep" knob - is that the reutz thing?
     
  3. JoeNeri

    JoeNeri Friend of Leo's

    Posts:
    2,526
    Joined:
    Mar 16, 2003
    Location:
    Silver City, NM
    That's my point. Proco changed the 308 chip but kept the resistor value, with the Rat2 being arguably very close to a vintage Rat in tone.

    Biyang kept the 308 chip but changed the resistor value = crap tone.

    Seems to me that little resistor is the most important element of the entire circuit. That's all I'm saying.
     
  4. 11 Gauge

    11 Gauge Doctor of Teleocity

    Posts:
    10,862
    Joined:
    Mar 21, 2003
    Location:
    Near BWI Int'l
    Yeah. It puts a 1K pot in series with the 47 ohm resistor that is connected to the 2.2uF cap.

    So that will give you from the stock frequency of 1540Hz (high pass filter) all the way down to 70Hz (with much lower gain, obviously).

    You might want to check out the Beavis Audio FKR (Four Knob Rat). I think there are at least two YouTube videos of it (by Fatback), and possibly others. Beavis adds the fourth knob, as well as LED clippers (both to ground and in the feedback loop, latter is like a TS), with switches for all the stuff. Kind of fun videos to watch, if nothing else.

    I believe that the Ruetz mod is referred to as "lube" when it involves a pot/trimpot. The more common Ruetz thing is to simply clip out the 47 ohm resistor, IIRC. Lots of resources to be found with minimal digging, so have fun!

    Oh - I think there is also a video by "Short Scale Mike" IIRC where he has a scratchbuilt Rat with the Ruetz control in it. I think he kind of explained it fairly well, but it's been some time since I saw it.
     
  5. 11 Gauge

    11 Gauge Doctor of Teleocity

    Posts:
    10,862
    Joined:
    Mar 21, 2003
    Location:
    Near BWI Int'l
    I think we are just splitting hairs, and probably agree on the same thing. I'd just elaborate that the Rat has a pair of those filters - both a 560 ohm/4.7uF cap AND a 47 ohm/2.2uF cap that are both equally necessary and unique to the pedal.

    ...Take either of those out of there (or screw one up like Biyang did), and the Rat vibe is gone, no doubt about it...
     
  6. JoeNeri

    JoeNeri Friend of Leo's

    Posts:
    2,526
    Joined:
    Mar 16, 2003
    Location:
    Silver City, NM
    Got it. Thanks.
     
  7. 11 Gauge

    11 Gauge Doctor of Teleocity

    Posts:
    10,862
    Joined:
    Mar 21, 2003
    Location:
    Near BWI Int'l
    Here's one of those videos by "Short Scale Mike":

    http://www.youtube.com/watch?v=oiHuUnlN4EA

    He's got the Ruetz thing in his (2nd knob from the right) that he refers to as TEXTURE, as well as a toggle (maybe two?) to change the diodes to either LED's or "lift" them out of the circuit.

    I wouldn't say the video is much more than entertaining and educational, and he kind of reminds me of "Nigel Tufnel with a proper education," but I think it is helpful just the same. IOW, I like Mike!
     
  8. bigp7099

    bigp7099 Tele-Holic

    Posts:
    884
    Joined:
    Oct 1, 2010
    Location:
    Brampton, ON
    thanks 11ga this is definitely going on the list, almost certainly the loris version
     
  9. 11 Gauge

    11 Gauge Doctor of Teleocity

    Posts:
    10,862
    Joined:
    Mar 21, 2003
    Location:
    Near BWI Int'l
    Well, NEXT revelation occurred today...

    I just got in my Voodoo Lab ISO 5 with an 18VDC tap last night. I was trying to think of what I might use it for...

    ...Contrary to popular opinion, running dirt boxed with clipping diodes at 18VDC does not "improve" the sound at all - it does not change compression/headroom/dynamics. This is especially true of the Rat, or even pedals like the OCD, which all have clipping diodes shunted to ground. IOW, there's just no cheating the laws of physics with those circuit designs.

    That said - the Mouse/Brownie/etc. have a setting for "diode lift," with the idea being that you could actually use a Rat as a boost. This is where IMO that LM308N truly comes up short, because it starts clipping on its own. The clipping diodes are really necessary to keep the (bad) buzz off the decay when the Dist is set beyond a certain point.

    But at 18VDC, it's a whole different ballgame, with no clipping diodes. Holy crap, does the LM308N ever sound nice that way, because you can actually "dig into it" and take advantage of its musical properties w/o the splat and fizz on decay. Simple principle, but since the original Rat didn't have a diode lift, who would have thought of it?

    To be honest, the LM308N chip is such an old design (remember - it has external compensation, which is kind of like your 2005 Corolla having a distributor, points, and condenser!) that I didn't think it would be good up to 18VDC. I thought it would be more like 12V max.

    If you have a Rat with the diode lift AND the power supply caps aren't super old (because they might be rated at 16VDC or 25VDC which could be cutting things a little close), give it a shot.

    This is actually really cool, because there is a "cousin chip" - the LM301, that is quite cheap. But since it doesn't have the gain of the LM308N, it just doesn't distort nicely, and there tends to be a bit of hiss. The 301 was super common in old audio gear. It also has external compensation, and the lower distortion might actually be advantageous with no clipping diodes.

    But the 308 is an absolute winner IMO with this setup. Again, it proves how versatile the Rat can be.

    My next Rat scratchbuild will have a charge pump so that I'm not dependent on that 18VDC tap.

    Just IMO, and FYI. Give it a shot if you have 18VDC and the diode lift. You might be splendidly surprised.
     
  10. Chiogtr4x

    Chiogtr4x Poster Extraordinaire

    Posts:
    5,064
    Joined:
    Mar 29, 2007
    Location:
    Manassas Park, VA

    Maybe its just a question of personal tone preference or loss of sound quality in a video recording, but I gotta say that my 'flawed' GFS Brownie (even if they did F**K up by sticking in the wrong value resisitor) sounds fuller/richer sounding, (smoother af high Gain, clearer at low gain, in all 3 modes) than anything I heard in that video. Different strokes I guess.

    I will admit though that the good sounds of the GFS are compromised when guitar volume is turned down from full, so I do want the correct component- plus I'm all for it sounding better;)
     
  11. 11 Gauge

    11 Gauge Doctor of Teleocity

    Posts:
    10,862
    Joined:
    Mar 21, 2003
    Location:
    Near BWI Int'l
    You have to remember that Mikey is running his Rat into a Tiny Terror in his apartment! Just about any distortion pedal will be reduced to sounding like a Metal Zone when the output transformer and speaker moving some air can't take some of that buzz away. Even a super clean tube amp will smooth things out, but you really need that "nominal volume."
     
  12. JoeNeri

    JoeNeri Friend of Leo's

    Posts:
    2,526
    Joined:
    Mar 16, 2003
    Location:
    Silver City, NM
    Hey Keith, any opinions on the NE5334 chip?
     
  13. Chiogtr4x

    Chiogtr4x Poster Extraordinaire

    Posts:
    5,064
    Joined:
    Mar 29, 2007
    Location:
    Manassas Park, VA
    Understood, thanks!

    Observation/question- See if you can follow this, (if I am communicating this OK)

    I found that with my Brownie (and this could be due to the wrong resistor situation) I could negotiate (dial in) best/most pleasing Lower Gain tone, if say from OFF to NOON on the Gain control, I ran the Tone knob in a parallel setting to wherever the Gain knob is- in other words there seems to be more treble edge at Low gain and the Tone control has to be backed off. But once I realized that, I have been able to get some very nice OD' tones, even an almost clean boost...After NOON-3:00 on the Gain control, everything sounds better tonally there, and then the Tone control was more useful as a cool shaper from as an ex. generally say a Santana/Clapton 'woman tone' w/ smooth saturation at lower Tone, or almost Fuzz Face spitty with the Tone cranked...Me likey this pedal

    ** BTW, the Brownie has the more conventional clockwise Tone control (Bass>Treble) rotation
     
  14. 11 Gauge

    11 Gauge Doctor of Teleocity

    Posts:
    10,862
    Joined:
    Mar 21, 2003
    Location:
    Near BWI Int'l
    It's generally very good for use in pedals - overdrives pleasantly, and has a much better noise floor than the older chips of yesteryear.

    The only downside is that it is a current hog, but it was never intended to be used in a 9VDC device. If you never use batteries it isn't a problem, but it should be a consideration.

    Actually, another downside is that a small percentage of that family of chips will unpredictably "latch up," which is typically not a pleasant sounding effect. But in a dirt box, it might happen and one would never even be aware!

    Lots of people like to put the dual version of this chip, the NE5532, in their Zendrive clones (since we will never know what Alf used, folks do their best guess, and this is a favored chip).

    The NE5534 also has some "external auxiliary functions" like the old LM308N does, but they aren't employed in the same manner. I found out the hard way when I used one in the runoffgroove.com Thor. The pedal didn't function until I pulled the NE5534 and subbed any old cheap TL071/LM741 in its place.
     
  15. 11 Gauge

    11 Gauge Doctor of Teleocity

    Posts:
    10,862
    Joined:
    Mar 21, 2003
    Location:
    Near BWI Int'l
    Yeah, even with the wrong resistor, many of those things are what the Rat does well. The wrong resistor simply prevents part of the circuit from functioning at the proper audible gain. Even with the right resistor in there, things tighten up and the bass isn't severe at lower gain settings. And yes - the tone control and gain control are extremely interactive.

    The big negative to the "wrong resistor thing" is that the upper mid filter can really "get the upper hand" and sound peak-y or even border on harsh, which requires cutting the tone control back more. And - it just won't clean up like a Rat with the "correct resistor" will.

    I can see it being appealing to some folks (this wrong resistor effect), especially those who don't have prior experiences with Rat pedals. Some folks love really tight drive tones and midrange by the bucketload, and that's what is happening in this specific case. Guys actually used to do something similar with a D+ and a MXR 10 band EQ set for a "frown."

    If you like it as is, then it isn't really "wrong," is it? But it's not correct to the Rat circuit as designed by ProCo, either. It's almost like the anti-Ruetz mod. Instead of a 1K pot in series with the 47 ohm resistor, you could put a 50K pot in series with a 560 ohm resistor! Maybe we could call it the "Ruetz Deux Mod!" :D
     
  16. Chiogtr4x

    Chiogtr4x Poster Extraordinaire

    Posts:
    5,064
    Joined:
    Mar 29, 2007
    Location:
    Manassas Park, VA
    ^^^ Interesting Rat stuff here (the whole thread), thanks! Kind of cool how this pretty old design keeps chugging along, just fine, it sure gets a lot of love.

    Funny how 3-4 years ago, when I first started reading posts here and on TGP (and then joining pretty quickly after that!...), and would come across the "What's your favorite OD or distortion?" threads (for the first few times...) , I remember noticing how many folks would answer "Rat!" for any of the "subset" of dirt questions: "What is your favorite OD/Distortion/Fuzz?" and Rat is still the answer for many- I had no idea years ago- but I'm beginning to see the light here
     
  17. JoeNeri

    JoeNeri Friend of Leo's

    Posts:
    2,526
    Joined:
    Mar 16, 2003
    Location:
    Silver City, NM
    My new pedal board:

    Pedals.jpg

    :cool:
     
  18. blowtorch

    blowtorch Telefied Ad Free Member

    Posts:
    26,667
    Joined:
    May 2, 2003
    Location:
    Wisco
    This is an interesting read. I still love my Brownie, wrong resistor and all, it kicks ass.
     
  19. artdecade

    artdecade Poster Extraordinaire

    Posts:
    7,937
    Joined:
    Dec 6, 2010
    Location:
    Twangsylvania
    Rats are great pedals. Tried and True.

    I have the new Nocturne Ubangi Stomp on the way. Its a Rat-variant designed with Filtertrons in mind.
     
  20. Chiogtr4x

    Chiogtr4x Poster Extraordinaire

    Posts:
    5,064
    Joined:
    Mar 29, 2007
    Location:
    Manassas Park, VA
    That's how I feel too, but if can sound even better, I'm all for it!;) Great thread about what makes a Rat "tick" ....thanks again, Keith! (11 Gauge)
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  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.