Almost done with the first one.
Used pin header sockets for the fets and caps, hopefully work out ok
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Hello!
I’m Karl, new in this community and almost new in the DIY synths.
May be someone could help me with my issue.
Is “FB1” a normal metal film resistor? The symbol used for it in the schematic confused me,
Also, “10R” equals “10 ohms”?
After finish soldering, I plug a 12v 2A AC-DC power supply ( - in the center pin) and once turn it on the FB1 resistor burns. I’ve checked all the circuit with my multimeter and seams fine. I filled everything except for the “eurorack power imput”.
Is my issue with the resistance FB1 or with the power supply?
Should I use a Power supply with the + in the central pin maybe?
Many thanks, noise and regards!
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Welcome to the forum!
Which is what it’s intended to do if there’s a power problem, though not everyone likes using 10R resistors for this and there are other options.
The schematic shows the +12V should be the one that connects to FB1. If it’s not obvious from inspection of the PCB, use a multimeter (with the board unpowered) to verify whether the center pin or sleeve connects to FB1.
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And the FB stands for ferrite bead, which in this case a normal metal film resistor is used. Yes 10R = 10 ohms
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The Megadrone uses center positive if you use the barrel connector.
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yes Karl center pin is + side of supply and not - minus so FB 10ohms will burn , you can cut wire on adapter and turn it around and solder and should yes should have 12 volt pos in center pin.
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What Value Caps are everyone using? The build calls for 1uf or 10uf. I am always a fan on bass, Was cutrious what i’d get with 4.7uf caps paired with 10uf or 22uf. any one deviate from the BOM?
I built it with three 1uF, four 10uF, and three 22uF. I posted about it here:
I think 4.7 would be a good choice.
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Okay so it looks like I got some S9018s despite the listing saying SS9018. Will these work?
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S9018 appears to be various companies’ knockoff of the Fairchild/ON SS9018:
There’s some variation, but they should be similar.
I’ve used S9018 in an SSO, but since various companies make them and since the avalanche behavior is not standard, you just have to try them and see, I guess.
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Thanks. I tried them and they work just fine.
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Chills!
Good build. Great demo.
Oh. And Welcome!
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I’m going to have to assume you are Scots or really want to be 
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yes .47uf, 3.3uf. 15uf and great results, larger the cap deeper the bass to a point , probably nothing over 47uf
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£160 yikes… think mine cost ~£20 over the board price… although not tested yet. and have the second one to build…
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Was going to finish No1 today, but realise I have no suitable caps in enough quantiy…
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but like here , who the f wants to work in a factory ? I just love the way rich people think that telling us we will make the country work again , working in factories making the 1 % billions of $ by killing ourselves …
oh shit sorry about that rant .
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Sing it Brother Scott!!
Actually been experimenting with the idea of a plethora of income streams where just 5 minutes work creates a small but always open income stream … just send me $50 every week for regular updates!!
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I got all my pots from Thonk today. It seems like I have been waiting forever. I suppose it is a long way from the UK to Australia. You guys posting all your builds havent made it any easier…LOL. Enjoy.
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I find it bemusing that a little synth company is reselling pots all over the world…
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