Friday 10 September 2010

DAM Fleshhead


26 comments:

  1. What transistors in the fleshhead mate?

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  2. I've seen gutshots with OC71s, OC78s and OC81s, but any PNP germaniums will do the job. I haven't built one yet but when I do I'll test out quite a few different transistors and post the results.

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  3. lol, in that case I might give it a miss, I don't seem to have much luck building germanium fuzzes!!

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  4. Question about the polarity of the caps on this one:
    - I see clearly the - side of the far-left 4u7 cap, but I'm curious about the other 47u cap and the 4u7 cap, is the little light-blue part on the top the negative side? It may seem an obvious question but I just wanted to confirm.
    Thanks!

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  5. With the radial electrolytic caps you can see a little "-" on one side of the outer circle. The 47u has negative to -9V, the 4u7 has positive to ground.

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  6. Hi again Ivlark. This is a sweet as fu*k sounding pedal, but is it right that the flesh pot should affect the volume when turning down the flesh, or have I done something very wrong? If it is right, do you know of any mods I could do remedy the volume drop please? Brill layout otherwise bud, thanks heaps! Milkit

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  7. Hi mate. The Flesh pot pans between two output caps, so in the far counter clockwise position it sounds very thin because it is cutting a lot of bass frequencies. By the nature of the beast you get a perceived volume boost when you turn it clockwise and more bass frequencies are introduced. If you look at this demo you can see it definitely sounds like volume is reduced in the far counter clockwise position:

    http://www.youtube.com/watch?v=4HkKoJ1Czrw

    Is that what yours sounds like or is the volume loss more extreme than that?

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  8. Yep, sounds exactly like the demo. Thanks duder, I thought I'd done something totally reprehensible!

    Now you know what's coming next don't you? Anything I could do to boost the volume, without changing the character of the sound? I guess I could put a boost after it right and just balls that bitch?

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    Replies
    1. Increase the 470 ohm resistor to 820 ohm or 1K and that should give you a volume boost. Or if you can fit it in you could even put a 1K trimmer in its place so that if it does change the character too much for you, you can easily just roll it back to half way to get you approximately back to the 470 ohm level.

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    2. Awesome, thank you good sir, I may even add it as a panel mount & have total control!! Providing I can squeeze it into the enclosure, space is of a premium in there!

      Thanks again Ivlark, sweet ass site buddy & a sweet ass layout/effect. Milkit.

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  9. I think a penny may have also just dropped, but has nothing to do with the effect. Ivl in Ivlark, a cool way of making an M? Milkit.

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  10. Ha ha, I thought everyone would get it when I first started doing it a decade ago, but it's funny how long it takes most to realise. I've known some people on Harmony Central for 7 years and they still don't know my name is Mark, and call me Ivy! I don't correct anyone and just wait patiently to see how long it takes! :o)

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  11. Enigmatic, I like it, leave it that way! Thanks Mark. Milkit

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  12. Hi, I'm new to this...

    The question I have is; what are the Q1 - Q2 - Q3? I know they're transistors but what kind?

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  13. Just to add, can I buy and 3 germaniums and drop them in any way round?

    Cheers

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  14. I didn't list a type because people often have their own favourites when it comes to PNP germanium transistors and I didn't want to list a mojo transistor that people would struggle to get hold of. I'd say a good matched Tone Bender set from Small Bear would be a very good choice, and they will mark which transistor should be used in which position.

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  15. Ok.. thanks. I see 'Small Bear' is a U.S shop, I'm in the UK.. Do you know of any UK places that do them?

    thanks for the speedy response ;)

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    1. Yes I'm in the UK too, and tend to buy from eBay, but you could try Doctor Tweak:

      http://www.doctortweek.co.uk/shop/catalog/browse?shop_param=ecid%3D18%26

      But the transistors there aren't measured so you're taking a bit of a risk. Even the matched pair doesn't really mean anything because we don't know what hfe they're matched at. As an alternative, although not in the UK, you could try Musikding:

      http://www.musikding.de/index.php/cat/c77_Germanium.html

      They're in Europe which makes shipping etc relatively painless and they do sell in certain gain ranges. I'd suggest a couple of transistors around 70 to 80 hfe for Q1 and Q2, and one around 120 - 130 hfe for Q3. I've bought PCBs from Musikding a number of times in the past and have never had any problems with them.

      When you're spending a few pounds on germanium transistors, I would probably suggest buying some PCB header strips so you can socket the transistors. This allows you to swap and change, but importantly also means that you're not going to damage the transistors when soldering. You'll be really annoyed if you buy 3 transistors and one gets damaged which means you can't finish your pedal until you place another order.

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    2. Excellent, Thanks for the help. I'll look into that...I've just been reading up on germaniums etc and I hear a lot about datasheets to find out the orientation. So If I get hold of a matched set, is there a place or document that would help me with positioning of them? i.e, which legs are ECB etc?

      Your help is appreciated...

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    3. Sorry, just looked at the Musikding and they appear to label the legs on their site

      Thanks!!

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  16. Ok, last one l0l,

    So if I order for example 3 x AC116 - PNP's, all at different gain stages as you mentioned, they will all be matched?

    Really sorry if these questions are brick wall head banging stuff....

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  17. Matched isn't really what you're looking for with this pedal. Matched suggests the gains of the transistors are identical (or at least very close), but that isn't important. Q1 and Q2 should be fairly close but being matched would be unnecessary. It's just a set with approximately the correct hfe (Tone Bender specs) in each of the 3 positions that you're more interested in. The only time matched transistors would really be required with effect building is if you were making a phaser or maybe an octave pedal where tight tolerances are needed to get the best out of the effect.

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  18. Right, gotchya... Well as I'm inexperienced I'll just go with the 1st lot (AC116's)as I wouldn't know the difference between them...I started with a SHO boost, than a Meathead so this seems like the next logical step... I'll get them ordered and have a go..

    Thanks for your help mate :)

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  19. i made a video demo of my build
    great sounding tonebender

    http://www.youtube.com/watch?v=7k9q5dU0J6I

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  20. as far as germanium fuzzes go, for me, this was the most easy going...mostly because every random transistor i used worked with out having to change anything. i settled on two untested toshiba's for 1 & 2 and gt308 i had marked with a gain of 117 for 3. even left it in my car over night where it was below freezing last night and it still fired up...not very nicely but better than you'd expect. fun stuff. maybe luck. i think it's a keeper.

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  21. I used GT308 for Q2 and Q3 (74 and 115 hFe) and an OC71 103 hFe for Q1 and it worked out really well. I didn't even have to play with my stash of parts, it just sounded good from the get go. I suppose it pays off to have a stash of Ge transistors measured for gain and leakage ready to pop into a circuit.

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