Clipping Diodes: germanium

[Chris60601]

Hi

*** possible silly question alert ***

I have seen several posts where it was mentioned replacing the current diodes with germanium.
Is there a suggested germanium diode to use or does it really matter?

Thanks!!

[Silver Blues]

Mostly it depends on the sounds you like. If you are satisfied with the outcome then the modification is a success. The most used germanium diodes are the 1N34A, the 1N60 or any of the Russian D9 series diodes (of which there are many, and they all sound subtly different. Here's a thread about them.) There's also the OA series diodes, which aren't seen quite as much but are an option.

Likely the suggestion comes from the lower forward voltage of the germanium diodes compared to silicon imparting a more pleasant or desirable characteristic to the circuit, or improving it's functionality (as in the Orange Squeezer or the Snow White Auto Wah).

[Chris60601]

Sweet! Thank you!

I have a set of these:

1N34A-DO-7
1N34A DO-35

So, to expand on my question, what does the DO-XX mean at the end of the above.
Based on your Russian diode example, I have to assume it's a country code of some sort?

[Chris60601]

LOL - looks like its the casing of the diode?

[dbat69]

The DOxx is the casing type like transistors (TO8, TO92, TO106 etc)

THe 1N34As in a DO35 are silicon workalikes (usually Schotkey diodes)

Germanium are generally DO7 or larger

[Chris60601]

Thanks guys!

I have a pretty fair idea as to what is what and what I wish to do.

Cheers!

[rocket88]

Just to expand on what's been said. Germaniun diodes have a lower forward voltage compared to Sillicon diodes, so one noticeable thing is the output is much lower, so if you swap Ge diodes in place of Si there will be a lower output and less max volume. To me Ge diodes sound warmer, clip softer, and a little fuzzier at the max then Si diodes. Most people say Si clipping is more on the harsh side. Think about a Ge fuzzface vs a Si fuzzface. The Si is more biting compared to the Ge, diodes are the same.

I started a thread about Ge diodes and there seems to be some, while rare, 1n34a diodes in a DO-35 package, which is smaller the the DO-7 package. For example, there are some that are green and gold in a DO-35 package that pass all the tests showing they are Ge not Schotkey. That doesn't mean there aren't schotkey of Si in the larger DO-7 package. Unfortunately there are fakes out there, and people try to sell the workalikes as Ge.

[Silver Blues]

^Truth. Generally be wary of diodes listed as germanium that aren't in a clear glass envelope (ex. DO-7). eBay is a great source for pretty much everything but do a little research before you pull the trigger on eBay germs, because there are a lot of fakes. According to what I've read (and someone correct me if I'm wrong) Tayda's 1N34As are fake.

[Chris60601]

I typically source through Mammoth and have had very good results thus far. There are a few others such as MKLEC that are up and coming and I REALLY like them. So this whole germanium thing is really new to me.

I am doing some homework and checking out 4 vids done by chromespherecom so I'm hoping to get a really good and basic understanding of them etc.

[Heath]

chromesphere is a cool dude with some really good info.  He prompted me to get some Blue Tak, one of the best ideas EVER.  

[rocket88]

silver, i've heard that too. i have some of tayda's 1n34a's in my stash, and at least the ones i got check out as Ge. i think at some point they changed to workalikes, but idk. i haven't gotten any from mammoth, as i just find them really expensive.

as far as ebay goes, you have to be very careful. i've got some great 1n270 Ge's that cost $30USD for 100 of them, but i see them go for a lot more normally. i was very wary, but there feedback checked out, i got them and they tested fine. before i got those, i order from another supplier that cost me like $50 or $70USD for 100 of them that were supposed to be made by Philips. when i got them i tested all of them and i got 4 that were in spec, 6 that were out of spec, and the other 90 were defective. thankfully i got a full refund, and found the others.

i've been lucky that i haven't gotten any fakes yet. do you're homework like you're doing and you should be fine. this thread, awhile ago for us to try to help prevent us grabbing fakes, would be a good quick read. it seems the ones that are most commonly faked ate 1n34a and 1n60p, so be wary. i've started hoarding different D9 series Ge diodes, cause they're cheap now, and sound great.

there's a lot of different Ge diodes out there are good, and are reasonably priced. plus, if you get some we can give you a job building the Ge Deathstar .

[Silver Blues]

Yeah I've been wanting to stock up on the D9-series diodes as well  one can never have too many choices for diodes, especially ones as diverse as the range found within the D9. you don't get near that much variance with silicon diodes, eh? most commonly used silicons are within the same forward voltage range and then you move into Schottky  and Zener and whatever which are a different animal altogether. The D9s and indeed any other germanium diode series are (within the series) practically the same diode but they all kind of sound different. It's an interesting distinction.

[Chris60601]

Rocket88 -

That is an excellent link - thank you!
I would love to have the DCA55 but $90.00 is a bit steep for my tastes.

What other methods are there to test? I really couldn't find a link on Smallbear (admittedly, I didn't really hunt for it either) as the germanium vids stated.

Muchly appreciated

[Silver Blues]

There are a few cheap analogues of the Peak tester on eBay, however their accuracy is sporadic according to sources among our community. But I mean let's be honest, they're not bad for anywhere from $12-$30. I think they're mostly fine for diodes, if that's your intent. But most good multimeters have a diode test function that measures forward voltages. Certain meters though have a voltage cap that makes them unable to measure high voltage diodes like LEDs (mine's like this), but I think the typical cap is in the 1v range which gives you everything but.

[Chris60601]

Good point - I'll check mine. I did find this: DUOYI DY294 but I also know that you get what you pay for too.

Thanks guys.

[Chris60601]

Damned it Silver Blues

now you got me thinking...  Had to go to the garage and check.
Sure enough, my BK 2706A has the ability!

[rocket88]

i hear ya chris. i got mine for $70 on ebay. best purchase i've made yet. i got it cause i wanted to get some Ge transistors and didn't want to deal with the tester we could build and all the math involved. plus, mark recommended it, and so far he hasn't steered me wrong yet. i'm thinking about getting the newer one that measure jfets, but its like $170, so if i get it i'd sell mine for what i paid.