What are your weekend projects?

[Travis]

I was thinking of trying the Ge giant out with some high gain low leakage Ge that I have to see if that gives it more of a volume boost with just the one tranny. The Ge diodes may just drop the volume a lot anyway, but I'm a little curious since I have some 300hfe+ low leakage stuff

I'll have to try it on the breadboard

[motterpaul]

Admittedly, I didn't read everything or think about the polarity that much when I went to the thread - because I am a little foggy this weekend and just wanted to get busy rather than think too much. I sort of assumed that when the switch to Ge was made that since it was still standard negative ground that someone had done the "upside down" circuit design as described in this article: http://www.muzique.com/lab/fuzzface.htm

Naturally, I see I assumed wrongly. I'll just chalk it up to "catching up" since I wasn't there to watch this project develop and I haven't personally seen discussion here of using NPN Ge transistors much at all in this site so far, so good to know.

Thanks for explaining.

[Travis]

We've talked about NPN Ge a lot here. Just a little info.. NPN Ge is usually less consistent than PNP Ge, more expensive, and much higher leakage on average. It can be convenient to use them to avoid charge pumps but I guess they're basically often inferior to PNP. We have bought tons of NPN useless crap to find a few good types, which have become much more expensive and hard to get in quantity now

[motterpaul]

Okay, to be more clear I went and looked up what I did yesterday. My first build was the first PNP version of the Green Giant (with the power inverter), it works fine, but a bit low in output.



then I built the final working version with two Qs, but the polarity isn't specified. I didn't have either Q model called for, all I have is AC125s, so when it didn't work I inverted the Qs, and it did work. It didn't sound great, though, so by that point I decided I would just wait until the DCA75 arrives and look at the specs and think about different transistors.

But now I also know it was made for NPNs,

So ... what I meant to say was "I haven't read much of anything good about NPN Germaniums here" - but yup, I did know the reason for all the power inverters and upside down circuits is because NPN transistors tend to be inferior. Also - flipping transistors is not ideal because collectors usually have more material than emitters.



So, the logical question is "How does the latest version Germ Giant sound with a power inverter and PNP trannies?"

Just wondering if anyone has tried it.

[Kinski]

Between multiple tours and having a 15 month old kid, I've had very little time to build recently. However I've got some time this week and the next. I'm really looking forward to building some stuff.

So I'll be building:

Mid-Fi Pitch Pirate Deluxe
Freppo Arcadia
DAM Super Bee

And a delay + boost in one box, for a friend. I don't usually build for other people, for a number of reasons, but decided to this time.

Im still waiting on a few parts in the mail.  But I can get started right away with what I have on hand now.

Once again, all builds will be coming from tagboards main site and this incredible forum and members.

[rocket88]

just to add to what travis said, remember emperor speaking here, there's a reason behind many of the issues surrounding NPN Ge transistors. back in the day, while the switch to NPN was occurring, the cost involved to make reliable, low leakage, good hfe transistors out of germanium was incredibly cost ineffective, ie very expensive. once it was determined that Si can be used, was more reliable, had lower leakage, and was cheap to produce NPN transistors Ge was tossed to the side.

fast forward in history, as the rest of the world moved toward Si and away from Ge, except the USSR who was technologically behind. as a result we have all the wonderful Ge transistors that have appeared, and begun to be horded.

now, there are many Ge NPN transistors that have stupid high leakage, i'm talking about well over 1uA, see GT404's, but there are also some gems, like the MP38A. now, as travis pointed out some of the good NPN's disappear because they're hard to find, and when you do they go for stupid money, just like we see with some "legendary" transistors. now the more i've been building, some of these super leaky NPN's may be food for NPN versions of some hard to build pedals like the ZONK Machine, which needs leaky leaky transistors.

many of the ones i've got stashed away that are good have been due to buying many dudes. also, there are some sellers that i've got a good relationship with so when they find what i'm looking for i'll get an email and we work out a fair price for either the whole stash if it's not massive, or a certain amount.

note i typically buy my Ge's 200-400 at a time, so i have a decent push when i'm looking to buy. if anyone is looking for certain ones let me know, i may be able to get a better price by adding the amount you want to my order, and i'm looking at putting one in this week.

[rocket88]

motterpaul wrote

Okay, to be more clear I went and looked up what I did yesterday. My first build was the first PNP version of the Green Giant (with the power inverter), it works fine, but a bit low in output.



then I built the final working version with two Qs, but the polarity isn't specified. I didn't have either Q model called for, all I have is AC125s, so when it didn't work I inverted the Qs, and it did work. It didn't sound great, though, so by that point I decided I would just wait until the DCA75 arrives and look at the specs and think about different transistors.

But now I also know it was made for NPNs,

So ... what I meant to say was "I haven't read much of anything good about NPN Germaniums here" - but yup, I did know the reason for all the power inverters and upside down circuits is because NPN transistors tend to be inferior. Also - flipping transistors is not ideal because collectors usually have more material than emitters.



So, the logical question is "How does the latest version Germ Giant sound with a power inverter and PNP trannies?"

Just wondering if anyone has tried it.

that one neil did is for NPN transistors. it's based on an idea i had of making a 2 stage version, i think he even called it the germanium rocket after me. that's whole nother beast from the normal one.

when you say you have low output, my question is are you getting low output with or without the clipping diodes in play? the more the clipping diodes are in the circuit the lower the output, and turns this from a boost to more of an overdrive/distortion. if you have the clipping diodes fully engaged and you're using Ge diodes like the rest of us, you will reach just at or just above unity gain with the volume full CW. if you're getting low output when the diodes are not engaged you need to play with the bias trimmer, maybe even up it since you're using a higher hfe transistor then most of us, again mine has an 82hfe transistor and beakers is in the 60's.

i'm also going to say this, not to seem like i'm telling you that you don't know what you're talking about, but the diagram you posted isn't really what you should be looking at, and is only going to add confusion as i'm sure the text that goes with it is trying to explain more then just the polarity of the transistor. what you need to remember is that the polarity of the transistor is needs to match up to the polarity of the effect, NPN you need negative ground, PNP you need positive ground.

[Kinski]

Hey rocket88, no big deal if not, but I'd be very happy to buy a set of transistors from you that would be suitable for a Maestro FZ-1. I'd rather do that than buy a bunch of transistors hoping for a few with the right hfe/leakage, as I don't really plan on needing many very leaky transistors for many other projects. If not, no worries, but figured I'd ask.

[rocket88]

not a problem. give me some time to mess around with what i got and see what would be good. any specific type you're looking for? btw, you're in brooklyn right? if so i'll be in green point on 6/29, and i forget where in brooklyn on 6/27 so we could meet up so you don't have to worry about shipping.

[Kinski]

Hey thanks! Much appreciated!

Yep, Brooklyn. Not far from Barclays Center. 6/29 is pretty clear for me. I'd be down to meet wherever. Round of beers on me! Or coffee, depending on the time of day.

As for type, I don't really know. To be honest, my Ge collection is entirely MP20a. All with pretty much zero leakage. You seem to have a ton of experience with Ge, so I'd trust you with whatever you think would work best. I'd just like to make a really great sounding Maestro Fuzztone using the layout from the main site. From what i've read, proper leakage (and maybe hfe?) is the key to getting the circuit to work as it should.

Layout: http://tagboardeffects.blogspot.com/2014/08/maestro-fz-1-fuzz-tone.html

[rocket88]

well i wasn't promoted to the emperor of the Ge Deathstar for nothing, lol. but seriously, i do have a ton of Ge's, and i've been planning on building a Maestro FZ-1, but haven't gotten around to it, i really want to make a slant enclosure for it and that's what's been stopping me. i'll do some research for the characteristics like leakage and hfe, as well as some of the model transistors people have used and come up with something that sound work. i'll let you know as soon as i get them together.

i'll be at saint vitus for the crowbar show that night, i actually have a second ticket cause my little brother backed out, so if you want you're more then welcome to join me for the show too. but i know that may be tough after just getting back from touring and having a little kid at home. but the offer stands.

[Kinski]

Hey thanks for the the offer to the show. That would be a blast but I don't think I could swing it that night. But if you are able to, we could meet a bit before the show and have a beer.

[Freppo]

Ciaran Haslett wrote

Here's my next week tied up...



Fitting and wiring an EDM production/training studio.  Bit of a learning curve with regards to CV inputs and, well, MIDI in general, but good craic all the same.

They're a local promotion company who also run some great "Off the Streets" youth programs and they finally got funding to make a studio.  Check out some of the boxes!

Currently laying out the workflow and making up some cables. Looking forward to Monday to open up all the toys and have a play

Sounds like a fun project!

Beside build a bunch of arcadiator pedals, this is my weekend project. I'm working on building a studio room at home. For many weekend to come... I used to have my studio at my brothers place, but he's moving. It has always been a dream to have my studio at home and now it's finally possible since me and my girlfriend recently bought a house. :)

 It was a cold attic that needs to be isolated, put in electricity and heat.



Slowly getting somewhere.. :)

[rocket88]

Dude that's awesome. Can't wait to see it done.

[Beaker]

Ow man, that looks like an awesome space! And in a swedish forest too - I can't tell you how jealous I am.

You really do need lots of insulation though, that far north!

[alex.s]

Going to playing a few gigs on bass for a friend in the coming weeks so will be working on some bass friendly stuff: a splitter, a sadowski pre/eq, an od and possibly another fuzz or two... More of that later as I might open a thread to nag all the bass players out there ;)

[Freppo]

Beaker wrote

You really do need lots of insulation though, that far north!

Thanks. It's a great little space. :) I will finally have a place to store all my stuff that has been all over the house, driving my girlfriend insane..

Yes. alot of insulation needed indeed. This is only the first layer of 3. I will leave the walls as they are. It only adds to the charm and acoustic properties.

Next up is putting in all the electricity and water, which will take a while before I can get it done since everyone is going on vacation now.

[heuermh]

At risk of turning this thread into asking-rocket88-for-stuff, I had an order from Bulgaria queued up but then didn't pull the trigger, because I'm not sure what I'd do with all that quantity.

I wonder if I might be able to buy say 10 MP38As and a grab bag of Ge diodes (D310, D9-whatevers, etc.) from you so that I can try out a few of the Germanium Giant builds?

[rocket88]

Shoot me an email and we'll figure something out.

[gabiru]

1. Delay + Booster. It's a Rebote Delay 2.5 (Tonepad etched PCB) plus a  Mark's LPB-1 vero layout.

2. Mark's LPB-1.

I built both for friends.

3. Double looper. I followed Mark's True By-Pass Looper layout, but with no buffer. I built this one for me. It'll help me a lot to organise my pedalboard. First channel bypasses distortion and the second bypasses whatever I turn on for leads (mainly a delay and a boost).