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Thursday, 19 September 2013

BJFE / Bearfoot Model G

I was struggling to get this one 21 columns wide max, so Miro will have to forgive me for the placing the Nature pot wires at different sides of the board.  Sorry mate :o)

Info about the original:

The Model G captures the unique voice and response of an often overlooked brand of amps from the 50s/60s ~ the Gibsons that were right there at the beginning with Fender, Valco ,Vox and Marshall..

Somewhere near the tweeds and supros but with a stronger and clearer voice, and a particular upper mid sound and snarl.

The Model G is related to the Honey Bee the same way a Gibson Falcon or GA40 is related to a Supro … cousins with obvious similarities, but important differences.

The volume, drive and nature controls are on both models.

The C knob is a big part of the difference – it controls several things at once:  the upper mids eq and snarl and  slight speaker compression … like adjusting to different speaker choices and ages or even like moving a mic aimed at the speaker.






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45 comments:

  1. johnk19 September 2013 at 16:49

    i'm going to build this one today but i'm counting 23 cuts, not 22.

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    Replies
    1. IvIark19 September 2013 at 17:13

      On reflection I shifted it round before exporting so you're probably right :o) I'll fix it, thanks

      Delete
  2. Doron Barness19 September 2013 at 17:48

    Fantastic sound! Great choice IVIark!
    what a great sounding pedal. I love the old Gibson amps and I was always surprised no one ever really payed to much attention to them.
    Early recordings by Les Paul from 1957 and such always show these Gibson amps.

    Definitely on my to-do list (number 6).

    Thank you

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  3. johnk19 September 2013 at 21:40

    i'd like to see the schematic for it to check the vero against it. I built it (i'm 100% certain that I didn't make any errors) and it doesn't work. are you sure that the drain of Q1 is supposed to go to ground? when I remove Q1 it kinda works but it doesn't have much output.

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    1. IvIark19 September 2013 at 22:21

      Q1 and Q2 are back to back clippers to ground, gate of one commoned to the source and drain of the other.

      Delete
    2. IvIark19 September 2013 at 22:36

      Oops, snip out the link between pin 6 and Q2 drain. God knows where that came from.

      Delete
    3. johnk19 September 2013 at 22:44

      That did it! VERIFY IT! it sounds great.

      Delete
    4. johnk19 September 2013 at 22:46

      update the layout without that link and you're good to go. so it should have 23 cuts and 6 link.

      Delete
  4. krzabe19 September 2013 at 22:50

    Just built it without the link between pin 6 and Q2 drain.

    It works.

    But the "C" is subtle. I could tell the difference when the pot is fully cw and ccw, but not that big of a difference. Maybe it's just my build.

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    1. johnk19 September 2013 at 22:51

      hmmmm. the "C" isn't subtle on mine.

      Delete
    2. krzabe19 September 2013 at 23:35

      "C" works. My crappy test amp couldn't tell the difference. Plugged into my Mesa and there you go :) Sounds alright but I think I'll stick with Honey Bee over this.

      Delete
  5. IvIark19 September 2013 at 22:53

    Link removed and I re-jigged things about a bit which shaved off a column. Thanks for that John and krzabe

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  6. johnk20 September 2013 at 04:22

    DONE! I LOVE this one! (works great on bass too!)

    pics:

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/BJFE/ModelG-01.jpg

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/BJFE/ModelG-02.jpg

    ReplyDelete
  7. Felix20 September 2013 at 06:29

    John you using white LEDs? does the colour of the LEDs matter for this build? or can i just use green/super brights (have spares)

    Gonna try to build this after i'm done with my Honey Bee and Sweet Honey, then do a side by side comparison of the 3, really interested to know the difference...

    or if somebody already has built the 3, maybe can do the honours?

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  8. johnk20 September 2013 at 06:48

    my leds are waterclear reds. if you use green ones, it'll have less clipping since reds have a lower forward voltage than greens.
    I've also built the sweet honey and the honey bee, and IMO, they're all great. I've also built the Sky Blue OD, the Dyna red, the stone grey distortion, the blueberry bass OD, the artic white fuzz, the pink purple fuzz and the little green wonder as well as the sea blue eq & deep blue delay and ALL of Bjorn's designs sound great.

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    1. Doron Barness20 September 2013 at 08:00

      between the Honey bee, Sweet Honey and Model G, could you describe some of the differences in terms of sound? Can you share a short audio clip with the 3 side by side?

      Delete
    2. johnk20 September 2013 at 08:16

      I use my pedals with a bass. it's now after midnite in socal. but i'll try to make a short clip of them tomorrow with a guitar.

      Delete
  9. Felix20 September 2013 at 07:55

    so what do you use now? these demos make everything sound awesome. is there a chart that shows the clipping to colour hierarchy? will socket them i guess... just gotta get the sockets

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    1. johnk20 September 2013 at 08:18

      I use whichever one that I feel suits what i'm playing. they all have a different 'voice' to them.

      Delete
    2. Felix20 September 2013 at 08:59

      ahh the joys of being a pedal builder...

      Delete
    3. Geezer24 September 2013 at 04:20

      John, where do you get the indicator/pilot lamps that you use on your pedals?

      TIA, G

      Delete
  10. johnk24 September 2013 at 04:37

    from mouser:

    http://www.mouser.com/catalog/catalogusd/646/178.pdf

    ReplyDelete
  11. Unknown18 October 2013 at 11:01

    Hi,

    what is R=2K61? 2K6+1 aka 2K7?

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    1. mirosol18 October 2013 at 12:12

      2610 ohm. There usually are some of these "non-standard" values on BJFE designs. I bet you'll be fine with 2K7.
      +m

      Delete
  12. Unknown4 March 2014 at 17:35

    What means 20K W? Is it a reverse poti (Alpha 20KC)?

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    1. mirosol4 March 2014 at 17:55

      That's W-taper, the kind that's used a lot on Tubescreamers.
      http://www.taydaelectronics.com/potentiometer-variable-resistors/rotary-potentiometer/w-taper/20k-ohm-w-taper-w20k-tone-control-potentiometer-with-center-detent.html
      +m

      Delete
  13. Unknown6 March 2014 at 19:10

    thanks m.

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  14. Unknown15 May 2014 at 14:02

    I like the sound of this one,but how can I make it brighter? the C knob turned all the way up it just starts to get to the right bright highs.is there a way to add a bright switch to this circuit?or what caps control the treble? maybe I can swap out different values to find what I like

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  15. Sergio10 June 2014 at 12:57

    Hallo, I m looking for the parts to build this one, but I cant find 2n5952 as easy as other FETs, mad professor seems to be a little picky about their parts, does it? So, should I ask Musikding for that FET, or there are other FET that can replace that one? Some favourite maybe?

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    1. IvIark10 June 2014 at 14:05

      Just use another 2N5457, or if you have a few different types like J201 try them too

      Delete
  16. Frederik Erikson23 February 2016 at 11:07

    Hi there,
    Can someone post the voltages and tell if he could sucessfully use a drop-in for the 2N5952 that I definitely cannot get hold of?
    Thanks a lot!

    ReplyDelete
  17. Adam9 January 2017 at 20:41

    I completed this and it works as expected but... only when I have the nature knob turned completely counter clockwise. If I turn it up at all there's a constant feedback noise. I'm guessing it's something with the wiring but not sure.

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  18. Daniel Davis23 April 2017 at 15:41

    Just finished the build and it sounds great, but I get a high pitched squealing feedback with the gain above 3 o clock. Anyone have any ideas? Could my LEDs be in backwards (used the side with the lighter patch as the - side, not sure if that is right)?

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    1. Iago26 April 2017 at 02:18

      Yes, the white marking means ground (shortest leg of a LED/flat side of the plastic casing). Even if you had soldered both LED's "backwards" it would still work properly (meaning, left-side LED with ground facing north and right-side one with ground facing south).

      Delete
  19. Daniel Davis24 April 2017 at 18:57

    Also thought that I should mention that I used 5mm red LEDS in place of the 3mm (have some red 3mm available, but can't figure out orientation since both legs are the same length and there isn't any internal plate visible).

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    1. Iago26 April 2017 at 02:21

      I wouldn't really bet on the LED's being the culprits here -I think it could be a series of other things, like: misbiased transistors, a solder bridge, a bad pot or some other type of building mistake, like a component soldered on the wrong place. I'd also try different op-amps, just in case.

      Delete
  20. HamishR17 January 2019 at 03:40

    I recently rejigged the layout for myself slightly (not much) and built this again. It works so well with my current rig that I actually went and bought an original to see how close it sounds. Well it sounds virtually identical! I was curious because i always found that the "C" control ("comp" on my original) didn't seem to do a great deal on my build. Happy to report that my build performs exactly as the original does - "C" does very little. It does something, but I would be hard pressed to say that I prefer it at one setting over another. It seems that a lot of Bjorn's excellent designs have a knob which does very little.

    The only difference I have found so far with components is that my original Bearfoot has three 2N5952, no 2N5457. It doesn't seem to affect the sound a great deal.

    This is probably my favourite BJF pedal.

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    Replies
    1. MAO19 September 2021 at 06:26

      Hey HamishR, I know its been a while, but any chance you measured the drain resistor and voltage for the output 5952?

      Delete
  21. MAO19 September 2021 at 06:27

    This comment has been removed by the author.

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  22. MAO20 September 2021 at 17:30

    Has the power resistor R15 @ 470R been confirmed? Seems odd as every other Bearfoot pedal with this same topology indicate 47R.

    In my build R15 @ 470R drops the supply voltage down to 8.2v, where 47R gives around 9.1v

    And considering the other versions all have the same R13 Q3 drain resistor value of 5k6, leads me to think R15 in this pedal should also be 47R.

    Also, with the 9.1v supply, I'm getting the 2n5952 biased at 5.3v. I needed to bump up the drain resistor to 6.8k to get closer to 4.5v bias.

    Still messing with it to hear what combo sounds best, but hoping someone can offer some insight.

    ReplyDelete