Friday, 28 August 2015

Germanium Giant

Hey Guys! Zach(rocket88) here and I'm very excited to join the tagboardeffects squad. So first, just have to thanks to Mark and Miro for not just the opportunity, but for really teaching me along the way so that I could even be in this position. I also have to give a big up, and thanks the rest of crew, Travis, Javi, and Alex. We're all in for an amazing ride, and great time to be a part of the site. But, onto my first post for the main site!

As some of you may know, I have been dubbed the Emperor of the Germanium Deathstar, mostly due to my obsession for all things Germanium. Awhile back there was a request for a layout for Nick Greer's Green Giant, which really was nothing more then an Electra Boost with a pot to control the amount of signal that gets clipped by the diodes.



 With Beaker, there was some R&D on this effect that ended up finding that the original Electra was all Germanium, so it was changed from all Silicon to all Germanium. This turned out to be not just a simple effect to build, but an amazing sounding one to boot. All of the discussion on it can be found in the Contributions thread, but there has been a lot of requests to make an official layout, which you will find below.

Now a couple of things to remember with this effect:

1 - you can use any diode, Si, Ge, LED, BAT, etc. as each one will give its own flavor, so socket the diodes and try whatever you got.

2 - you can use any NPN Germanium transistor, as they will change the effect slightly. MP38's are a little dark, tesla 104NU71 are a little brighter. so don't be afraid to experiment, but try to keep it less then 100hfe

3 - the trimmer sets the bias, you can do this by ear.

I figured I'd include a PNP version, as some people may have a lot more PNP Germanium Transistors then NPN ones. This layout is also verified, but, and this is a huge but, you will need to audition transistors, as no one really said what they used that sounded good. Do NOT use AC125's or AC128's as they will not sound good at all in this circuit, so you will be majorly disappointed if you try to use them.




Requested PNP layout without the inverter.

Also, i forgot to say to socket the input and output caps to. i found the stock 100nF caps to be a little more trebley then I'ld like, especially for my bass. In mine I've got 470nF caps for both input and output caps, which makes it much fuller, and retains the all the low end of my bass when compared to the bypassed signal. So by all means try different combinations.

49 comments:

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    1. accidentally set it to original size. better now? haha

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  2. Excited to see more from you! What's the IC in the second picture?

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    1. Oop. Should be labeled, I must have lost it when I added the new footer. I'll fix it. But, it's an ICL7660S. It's just an inverter for the so you can daisy chain the PNP effect with all your other NPN effects.

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  4. Love your layouts Rocket... nice to see you posting on the main board here!

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  5. Also, I can confirm that GT2306, 1T308V and 2SA49/51 sound good in this circuit if anyone was looking for some ideas.

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    1. Yep, bro! Something I've desired to assemble for a day or two lol. It's a germanium 5 knob Fuzz factory with light mods, an enormous silicon fuzz all custom made circuit 5 knobs and a 4 tone selector rotary, and a bonus clean increase with 4 tone selector to allow you to get from sparkle to hot soil and overdrive. Pedal is neato. Great walls of fuzz, squelch, dirt, high gain, self oscillation, boost, and yep that also. musicalstudy

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  6. should just add that the transistors Roberto mentioned would be for the PNP layout, NOT the NPN.

    leo, glad you do. hopefully i'll have time to do a bunch more. i've got some i haven't published before, so keep tuned. i know with alex on board there's going to be A LOT coming. he really does an amazing job.

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  7. Do you have a schematic for the PNP version? Is the clean actualy mix in clean signal or is it a sustain level? Thank you for posting this, great to see more people to add to the site.

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    1. hey chris, there's no schematic for the PNP version, because all i did is swap the NPN transistor with a PNP one, and added the charge pump so you wire it up like normal.

      to answer your question about the clean pot, what it does is control how much signal goes through the diodes to ground. essentially, it's a distortion control, but it acts a little different. full CW you'll get a clean boost, and full CCW you'll get full distortion. as you put the diodes into the circuit with the pot you'll get clean signal with some distortion, and the more CCW the ratio of clean to clipped signal changes adding more clipping.

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  10. Great work Zach! I'd like to build a PNP version without the charge pump, but with positive ground, because i will only use it with a battery. Can you please also make a positive ground PNP layout?

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    1. thanks man, and no problem buddy. it's up for you or anyone else who wants it. in any event, since there's no electrolytics to worry about, you can easily do it right from the npn layout. all you need to do is put your ground wire to where the positive should be, and the positive wire to where the ground is supposed to be.

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  11. Hey there all!
    Nice work Zach! Great to see some other influences on the site. Music one of the oldest art forms lives in the heart and soul of every being! Anyways, a question, is this circuit kind of a booster/OD? I'm still a virgin to making a good sounding full germanium build. Most of them I've made have been ummm alright but I feel that way about fuzzes in general, so far. Anyways, thnx for the effort to you and everyone......

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    1. Yes it is. You can use it in different ways, you can use it to effectively replace a Tubescreamer, as it goes up into that territory on full dirt setting - but you will only get a slight boost. Turn down the amount of dirt mixed into the signal (turn mix pot clockwise), and the volume goes up significantly.

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  12. Cool thnx Beaker!
    Gonna try and build it...gotta keep on swimmin...

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  13. Built it!
    Works and sounds really good...there are a few things though. I used a 20kb pot and the 100ka. They are both maxed out and still not enough output. Any suggestions?

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    1. with everything maxed you're probably at a hair above unity. just as tavis said it's just the nature of using Ge diodes for clipping. it has to do with how much voltage can go through before the diodes clip the signal, which is known as forward voltage, is much lower then if you used something like silicon, LED's, BAT diodes, etc.

      now, to answer your question about what you can do, you wire up a second germanium giant without the diodes, and wire it up as a switchable after effect booster.

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  14. That's kinda just the nature of this effect. With the Ge diodes fully clipping the signal you aren't left with too much output. You could put another gain stage at the end, but I probably wouldn't use an LPB-1. Something like a super hard on or bacon bits would be better

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  15. Ok, I have neither. What about a Keeley katana boost. How would that compare?

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    1. i don't see why it wouldn't work. if you've got the katana boost boxed up, just put it after the germanium giant to see how they sound together. what's the worst that can happen? it will sound like poop. lol

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  16. Gotch ya!
    Lol! I have to ask sometime cause the way I live I only get to play with gear 1-2 a week. Anyways, thnx. So which one would you use Travis. The mad bean or SHO?

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  17. So, I built the SHO and put it front or this and it worked and sounds good at bringing up the level. Thnx everyone!

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  18. Hi all, just to say that it works very well, I used a 2SB175 transistor. Thanks for your great job !

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  19. Would it be possible to post a Video - From anyone who has built this pedal, I'm intrigued.
    Just a few chords or something...anything really

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  20. less than 10 parts and 15 minutes of build time, sounds great too!

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    1. glad you dig it carpe. it's one of those effects that proves that a circuit doesn't have to be complex to sound great. definitely one of my favorite pedals.

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  21. Hi, I measured something like 100 transistors with the germanium transistor tester (which thanks to Ivlark I built myself). except for the few 2sa12s which were mostly very low leakage with hfe around 30,nearly all of them were of hfe's around 150 to 250. it seems that the usable ones must have moderate leakage with hfe's around 50 to 150. am I right? do you think there is something wrong with my measurement. by the way the trannies were Gc301, 2sb75, 2sb54, 2sb175, 2sb176 and 2sa12.
    thanks a lot.

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  22. Built it. Sounds nice. I like it more with silicon diodes. Also I lowered the 100nf input cap - original is a bit muffled to my ears.

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  23. Loving this thing more and more. I'm wanting to get rid of the pots as I always leave it on full and would love the simplicity. Can I just put like a 100k resistor after the output cap and connect the diodes up to the output rail? Thnx so much everyone:)

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  24. Wow! This thing sounds great! I've got a few ideas for this one...

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    1. oh do tell bro. would love to know what you've got in mind.

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  25. For anyone interested that may not know, this little guy sounds great in front of dirt- like an already dirty amp- and can really bring a transistor amps fizzy dirt to warm fuzzy dirt ( really fixed my princeton 65's harsh gain channel) on an otherwise decent practice amp.

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  26. Hey there, this my first post, and build, I'm a total noob. I built this little guy yesterday and all I get is hum when I plug in. I will post some pics, but was hoping someone might have a simple thought for a simple builder that might solve my most likely super noob error. Thanks in advance .
    A

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    1. hey man. post what's going on with your build and your pics in the debugging section of the forum. what transistor are you using? what kind of hum are you getting? if you're using germanium sometimes they can be a little noisy, like a white noise in the background when you're not playing. hope to get you up and running right, cause it's definitely an awesome pedal.

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    2. Cool will do. Actual it happens when I add power. I was expecting some hum and such, as it's not boxed, I was just trying it out first. I'll post in debug. Thanks for the reply! A

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    3. anytime man. if you're getting signal, but there's a hum when it's powered on, if you're using a cheap power supply it could be that.

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    4. Testing with one spot but nothing else in the chain. there is a very faint signal. If I disconnect ground, everything goes away.

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    5. definitely a build error. post everything up in the forum. we'll be able to get it sorted out.

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  27. if I use a DPDT and a millennium bypass, where do I connect the cable LED +?

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  28. Hi There! I've done my first build from this awesome community! Keep up the great work!!!

    I´ve build the PNP Version (with Charge Pump) using AC126 (HFE slightly hot around 110) and 1N60 Diodes... sounds pretty cool! I used a jumper between Clean1 and Clean2 to simulate a "fixed full gain" control.

    Just one side note, which might be completely wrong: I think the jumper from B17 to D17 in this version is wrong... it puts both sides of the diodes to ground... (my build works nice without that jumper)

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    1. hey man, glad you're enjoying it. i see what's going on. you're right, the link is messed up and shouldn't be there. right now i don't think you can bias the transistor with the trimmer. all you need to do is add a double link to connect the top leg and middle leg of the trimmer.

      i've made the change to that board. great job man.

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  29. Wow Zach, thanks for this layout brother! I just finished my second one on the strength of my first build. The second one is even better. This time I added a DP switch with 1N34 one one side and 914s on the other. This one is pnp with the 7660 inverter. I used a 2n2907 transistor because it was the only pnp in the drawer! Stable and wonderful! Quiet and juicy.

    I put the bias pot on the front with the other controls on both my builds and I am so glad I did. You can adjust the overdrive so much better with the bias off board. Depending on your guitar's pickup strength and how hard you want to hit the diodes, the bias pot will see a workout finding the sweet spot! Having the bias on the front panel also lets you go from a clean transistor boost to a dirty boost. When you go full diode and crank the bias right up great gobs of dirty things start to happen!

    It really is the best overdrive I have ever played, my very favorite. I have been playing overdrives since the late 70's.

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    1. al man, glad you like it. i can't take all the credit for this one, beaker did most of the leg work with testing it and finding out how to really make it as good as it is.

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