Greer Green Giant

[traktop]

Thanks

[rocket88]

Just remember that if you're doing the germanium giant you want an npn Ge transistor and diodes. Check notes on the most recent layout posted. I'm not worried about your build you'll be fine. Lol

[Silver Blues]

Or alternatively if you want/have to use PNPs find one of the two layouts with inverters on them and build that.

[traktop]

I´ve just built the first layout that rockett 88 posted at the beginning, (the one with 2n3904 transistor and 1n4148 diodes), since got no GE transistors at hand, (got 1n34a diodes though).
I´ll let you know how it went

[rocket88]

True. You can put a socket in for the resistor to ground on the transistor so when you do get a Ge transistors for if you can just adjust the bias until is good, and obviously sockets for the diodes, but you probably already do that.

[Kinski]

Sorry to ask, but not entirely sure, is this layout verified/working?

[rocket88]

No. Ignore all layouts with a tone control. There's way too much volume loss, and it's being worked on. The ones that are verified are the ones without the tone control, that means both the npn and pnp ones.

I haven't had time to revisit the tone control ones once the low output was discovered. Hopefully I'll be able to in September.

[Kinski]

Cool. So this one works then?

[rocket88]

yep. just remember you'll have to try different transistors to get something good, and adjust the bias accordingly.

[Kinski]

Only ones I have are a huge pile of mp20a. A pretty good range of hfe. All zero leakage. I imagine one of those should work, yeah?

[rocket88]

Give them a shot. If forget what I ended up using that sounds good in the pnp version, just avoid ones like ac125's. If I remember correctly the same rules as the non version hold true, so hfe 50 to 90ish.

[heuermh]

Yeah finally got to put that bag of goodies from Bulgaria to good use!

Had a blast with this one swapping out transistors, capacitors, and diodes left and right.  Settled on 90 HFE MP38A, 330uF caps, and what I think are SFD 106 Ge diodes.  They had a something not quite right that I really enjoyed.



Thanks again!

[Silver Blues]

Yeah the SFD106 sound neat in this circuit.

[Kinski]

Finally built and boxed this thing. Used a rotary to select between 4 different GE diodes. Also added an input pot, and an external bias pot. And wired a Marvel Drive running into it on a stomp switch.

THIS THING SOUNDS HUGE! Thanks to all!

[Beaker]

I'd love to see that one. Please post pics!

[Kinski]

Sure, here ya go!

I forgot to mention that I also added a SHO at the end. The SHO is fixed with an internal trimpot, set and forget. Just enough to give me some extra volume on tap.

Sorry, no gut shot right now. I was too excited to get this thing going and forgot. But I'll post some internal shots soon when I have a free moment. Its not that pretty anyway

[Kinski]

Wait, sorry. I did NOT use a SHO. I tried a SHO, but it added too much white noise. So I ended up using a Mr Black Tiger Boost. Much better!

[Silver Blues]

Nice, that's a great idea. I might end up boxing mine with a booster as well, it's pretty quiet at max clipping.

[Kinski]

Still loving this build. The GE Giant sounds great. Although, I have since decreased the input cap a bit as I found it too dark with a neck humbucker. And I don't really use the diode rotary as much as I thought I would. Bit overkill with that, but it's still nice to have.

And it loves being boosted by the marvel drive. Sounds very much like Sunn O))).

[tahl74]

Hi! Looks very good! I have no idea for Clean pin 3? Please explain.. is it solder to ground? Thanks!