Wednesday, 22 May 2013

Himmelstrutz Gramps

Modded slightly so the Treble/Presence pot is external (like the Gramps+), but you can always use an internal trimmer like the original if you prefer.  Sw1 in the layout is the "Temperament" switch in their info, the gain and sag switches are both internal jumpers in the original.  I'm not entirely sure how much difference the Sag switch will really make because all that does is put a 150R resistor in series with the supply.

Info about the original:

Jump on Gramps to daze and confuse. Which of course will make your band and audience gratefully amazed. Or use it on all guitar tracks on all your recordings for that not so shimmering, bowl movement provoking, beautiful sound.

Like the rest of the Himmelstrutz pedals Gramps will sound great at any volume. Just more crazy. And fuzzy. Of course it's also capable of generating lovely, magic distortion sounds which will transform your sleepy life into a creamy happy mess.







43 comments:

  1. Sounds the tits! C'mon slow arse builder man, finish my man-cave!

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  2. If it really sounds like that, it would be quite a good fuzz tone.

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  3. In Australia this pedal is selling for $425. For the price we can build them that should be enough incentive to try this one, plus the great clip.

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  4. I think the tone lugs 1 and 3 might need to be reversed for the standard "clockwise for more treble" operation: I know it's drawn that way in the FSB schematic, but it looks like a BMP style tonestack to me, so I'd assume lug 3 should be the high pass (2n2 cap).

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    1. Yeah I just did it as per the scheme, I'll edit the layout when it's been built by someone

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  5. 2SK170GR's are expensive! Can anyone recommend a cheaper alternative?

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    1. Nearly all through-hole JFETs are now from most places, unless you're lucky enough to find a bargain in bulk. You can still get them pretty cheap at Futurlec though.

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  6. Ah, that's a much better price than I'd found on Ebay. Couldn't set them from my usual supplier. Thanks Ivlark!

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  7. I can't seem to find the scematic for this. I have built though I used 2sk117's as I had those on hand. All I get is clean sound coming through. Do you think the problem is the fets, I checked over several times that it is correct as per your layout and for solder flow or bad cuts.

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    1. 2SK117's should be fine, they're just slightly noisier 2SK170's anyway I think. Scheme is at FSB but you'll need to be a member to get access to the Boutique section. I'll give it the once over again tomorrow but I'm pretty confident it was right.

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    2. I found the schematic - helps if you log in fsb when searching. Your layout is the same as the schematic - I will try re-flowing later today and I will recheck everything again.
      Thanks - i've built some great pedals from here - really appreciate everyone's efforts.

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    3. No luck with re-flowing - I checked everything again and again. I did notice that the clean sound is for single coils, when I use humbucker on lower strings and pick harder that there is a nice fuzz trying to come through, though it's very broken up.

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    4. I tried some sk30a's that I had also and it sounds clearer but much like an od more than fuzz. Might just have to order some 170's to try. I want to try a fetto also so I might order a few.

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  8. I got this working with the 2sk117's but reducing the 10k resistor sound great thanks - might order those 170's just to reduce the noise a bit.

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    1. SK117 and SK30 want different value (lower) drain resistance to sound decent, but having tried them both in my Fetto, I can say there's more difference between those and the SK170’s than simply lower noise. The 2SK170 is THE one to use in these circuits.....nothing else I've tried even comes close.

      $0.02

      Geezer

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  9. I found by putting a jumper instead of the 10k and just using the trimpot gets the best sound. Sounds great, I've been building a few fuzz and distortions with fets and they sound great. Nocentelli was correct about the tone lugs being the wrong way around - swap 1 & 3.

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    1. Thanks David, I'll alter the layout

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  10. I'm having some difficulty even locating some 2SK170GR's nevermind paying through the nose for them! I have found 2SK170 though, will that suffice? What is the 'GR' bit about? Thanks.

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    1. Banzai stocks BL version, not sure about the suffix either but I've used them instead of GR before.
      Since I never had any GRs, I can't say how they compare. :)

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    2. Correcting myself, I've found this info:

      "Drain current specification is the difference among the classes of these FETs. According to Toshiba Idss classification for the GR is 2.6 ~ 6.5ma, BL is 6.0 - 12.0 ma, V is 10-20 ma."

      Some threads at Harald's suggest that in Himmelstrutz stuff BL sounds even better than GR.

      Also, not sure if one needs to look into getting a matched set?

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  11. Hi!

    Can I use 220uF capacitors in place of the 100uF ones?
    What will it change?

    Thanks!

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  12. I've been using this on my pedal board with the 2sk117's but the 170GR's i ordered came today so I stuck them in and it sounds even better. I've made at least 20 fuzzes from this sight and this one will be staying on my board as a standard I think.

    Great layouts and thanks again.

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    1. Thanks David, that sounds like it needs to be tagged as verified to me. Nice one

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    2. Where did you grab your 170's from, David?

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  13. This comment has been removed by the author.

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  14. I see switch 1 is SPDT on-off-on. What is 'sag switch?
    Just a SPST on-off?

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  15. I also see the 'gain' switch. Is it also a SPST on-off?
    Making 3 switches 1 SPDT and 2 SPST's?

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  16. Hi!

    what is the purpose of the bias trimmer and how do you set it please?

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    1. It biases Q1, try to get 4.5V at the drain

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    2. apologize my poor English vocabulary, but what's the drain? ;-)

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    3. FETs have three pins, Source (S), Gate (G) and Drain (D). Take your DMM (digital multimeter), set it on voltage (V). Point the common lead (usually black) to board grounds and the red lead to Q1 drain. Then tune the trimmer until you have 4,5 volts on Q1 drain.
      +m

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    4. ok!! now i know why all the transistors in your layouts doesn't have the E B C letters. I thought emitter base and collector was the standard for all trannies...
      Thanks to make us rise,little by little, in the world of electronic!!

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    5. please don't break down guys...
      Have I to make this setup with the 9v power on, or it doesn't matter?

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    6. https://en.wikipedia.org/wiki/Field-effect_transistor
      https://en.wikipedia.org/wiki/Bipolar_junction_transistor

      Yes. You need to have the circuit powered or you won't see any voltage on the Q1 drain.
      +m

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    7. i've just bookmarked the two links. it seems that i have readings this evening...my wife won't appreciate it... ;-)
      thanks for all

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  17. Hi!
    Trying to bias Q1.
    I can only get 5,88 to 5,90V by turning the trimmer...
    I have soldered a trimpot 10K "SINGLE TURN"; Is it the right component?
    thanks

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  18. I tried 2SK170-GR's and they didn't work well in mine at all but 2SK170-BL's work great.
    I also had to change the 10K bias resistor to a 1K to get it to bias properly.
    and BTW, you can also use J201's in it if you twist the gate and source pins.

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  19. DONE:
    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/Gramps/Gramps-01.jpg

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

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  20. Is there any other transistor that can be substituted in place of the 2SK170GR ??? even if i have to twist the pins around would be fine.i have a truck load of different trannies just wondering if something els i have will work?

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  21. For those that they wonder what fet to use…I’ve tried a few with the fetto standard and I hope it will be the same thing here.
    The 170BLs are smoother than the 170GRs, but they lose a little in attack and presence. Now for the 117 (BLs is what I have) I think they make it sound more like a distortion on lower settings with a nastier sound, but with less dynamics than the 170s

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