Marigold build - and diodes of the germanium variety...

G

Gremson

New member
Hey guys!
First post here. I've been building pedals off and on, casually and professionally for several years now. But most of my experience is "paint by numbers" building. Just following BOM sheets. I'm fine at following instructions, but I'm still pretty inexperienced in some fundamentals of pedal building.

I'm finally looking to branch out a bit, and the Marigold fuzz looks like a fun build to experiment with sourcing obsolete parts and better understand how some components interact with each other.

I found a couple varieties of OC140s through SmallBear, and I intend to socket and try different transistors to find what's best for the build.
I figure it's a good idea to do the same for the germanium diode, but I don't quite understand what parameters I should be looking for in that. Would basically ANY germanium diode work? Why would I pick one over the other? The BOM suggests a CG92H, which doesn't seem easy to find. I'd appreciate any alternatives I should look into, and I'd love any explanation on why it's a decent alternative to anything else.

Thanks for your guidance!
 
Gremson said:
Hey guys!
First post here. I've been building pedals off and on, casually and professionally for several years now. But most of my experience is "paint by numbers" building. Just following BOM sheets. I'm fine at following instructions, but I'm still pretty inexperienced in some fundamentals of pedal building.

I'm finally looking to branch out a bit, and the Marigold fuzz looks like a fun build to experiment with sourcing obsolete parts and better understand how some components interact with each other.

I found a couple varieties of OC140s through SmallBear, and I intend to socket and try different transistors to find what's best for the build.
I figure it's a good idea to do the same for the germanium diode, but I don't quite understand what parameters I should be looking for in that. Would basically ANY germanium diode work? Why would I pick one over the other? The BOM suggests a CG92H, which doesn't seem easy to find. I'd appreciate any alternatives I should look into, and I'd love any explanation on why it's a decent alternative to anything else.

Thanks for your guidance!
Click to expand...
Welcome. You might have a look at our esteemed constituent @Chuck D. Bones’s suggestions for modding the Marigold (under the Boneyard section). If you have the opportunity or means to breadboard the circuit, better still. Then you can check out the mods for yourself and pick those that best suit your setup.
 
For the Ge diode, any Ge diode should be fine. I believe, based on my googling, that the CG92H IS equivalent to an OA95 and has a Vf of about .4v at 1mA. So a D9G or D9K should work and they're easy to find on eBay or StompBoxParts.

I'm sure you could use another diode type (Si, Schottky, or BAT) but we won't give quite the soft knee that a Ge diode does.

Edit: this thread give some more details about the Marigold replacement options: https://forum.pedalpcb.com/threads/replacements-parts-for-marigold-waddle-and-backfeeder.6358/
 
leadfoot said:
For the Ge diode, any Ge diode should be fine. I believe, based on my googling, that the CG92H IS equivalent to an OA95 and has a Vf of about .4v at 1mA. So a D9G or D9K should work and they're easy to find on eBay or StompBoxParts.

I'm sure you could use another diode type (Si, Schottky, or BAT) but we won't give quite the soft knee that a Ge diode does.

Edit: this thread give some more details about the Marigold replacement options: https://forum.pedalpcb.com/threads/replacements-parts-for-marigold-waddle-and-backfeeder.6358/ dinosaur game
Click to expand...
If the BOM calls for a CG92H and it’s hard to find, common alternatives like 1N34A, 1N270, 1N60, or OA90/OA91 are all solid options. They’re widely used in vintage-style fuzz builds and generally fall into a similar forward voltage range. The exact Vf can vary a lot from part to part, so socketing is a great idea — you may notice differences in output level, compression, and texture.
 
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