# Replacements parts for Marigold, Waddle and Backfeeder?



## Dali (Apr 18, 2021)

I got many parts in 3 futur PedalPCB build that seems a bit rough to get. Any of replacements or suggestion?

I've checked Tayda, Mouser.ca, Digikkey.ca and Small Bear. I know I can gamble on eBay and Amazon...

*Marigold*
CG92H Germanium Diode (What is this thing?)
OC140 Germanium transistor (12$ for one! on eBay)

*Waddle*
LM13600 (eBay 4$, +100 sold)

*Backfeeder*
2SC732 transistor (11$ eBay for 5 pieces)
2SC2603 transistor  (9$ eBay for 10 pieces)


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## mmm (Apr 21, 2021)

Waddle - LM13700 replaces the LM13600 @ $2.02 -https://www.taydaelectronics.com/lm13700-lm13700n-operational-amplifier-ic.html

good luck with your shopping


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## Yroc006 (May 6, 2021)

Dali said:


> I got many parts in 3 futur PedalPCB build that seems a bit rough to get. Any of replacements or suggestion?
> 
> I've checked Tayda, Mouser.ca, Digikkey.ca and Small Bear. I know I can gamble on eBay and Amazon...
> 
> ...


I was actually just looking up the subs for the Backfeeder and came across this.






						2sc732 Cross Reference - Electronic Circuits, TV Schematics, Audio
					

Semiconductor (Transistor, diode, IC) Cross reference




					english.electronica-pt.com
				









						2SC2603 Cross Reference - Electronic Circuits, TV Schematics, Audio
					

Semiconductor (Transistor, diode, IC) Cross reference




					english.electronica-pt.com
				





Not sure how accurate it is yet, and the pinouts will be different, but it gives several more common options to the part looked up.


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## peccary (May 6, 2021)

I remember looking up the OC140/OC139 a while back for a pedal I wanted to build and coming up with blanks. After a little research I found that the MP38A was another well liked, low gain NPN Ge transistor and I bought a lot of 20 from a Russian seller to try out.

That was almost four months ago and they haven't gotten here yet  

If they ever get here I'll let you know what I think, but if you can get other low gain germanium NPNs the'll likely be worth a shot.


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## finebyfine (May 8, 2021)

Saw in a review of the uberdrive on the store that someone replaced 2SC732 with 2N5089s and that 2N5088s can work too. Socketed 2n5089s in my uberdrive but am waiting on other parts for it too. Adjusting the pinout was a pain in the ass.

In the marigold thread if I remember right the consensus was any germanium diode for cg92h


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## Feral Feline (May 8, 2021)

I like to sub out Schottky for Ge clipping diodes... they have a similar forward voltage and the Schottky are temperature stable.


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## mdc (May 20, 2021)

@Dali sorry for the slow response!
For the marigold:
Any Ge diode should be fine.
The NPN Ge transistor should have little to no leakage and an HFE around 80 (+/- 20 or so). 

OC140 is good because they tend to be really consistent. I have a bag with maybe 8 or 10 and they test out very similar to one another. Unless you have a DCA55 or similar meter it's probably worth the extra couple dollars to just buy a transistor that's already been tested and sorted from smallbear or wherever. Whatever you do, I'd socket it on the PCB.

The zener diode is there to help bias the collector voltage on that transistor, so you may have to futz a bit with that component to get everything in the ballpark depending on the transistor itself.


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