A lot of them are gonna be around 68 - 76R
Tayda has them for .08 cents
https://www.taydaelectronics.com/axial-ferrite-bead-76-ohm.html
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- & 3. Yes you need one pin for each position in the housing.
Pick the pins and housing from the same series.
If you buy the housing from this list : https://www.taydaelectronics.com/connectors-sockets/wafer-housing-crimp-terminal/serie-2500-2-54mm.html then the pins are these ones: https://www.taydaelectronics.com/connectors-sockets/wafer-housing-crimp-terminal/serie-2500-2-54mm/crimp-terminal-connector-2-54mm.html
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Duuuuuude. thank you 
Great post, I just put in my cart (for the cost of one eurorack) enough components to build like 20-30 modules. Most excellent me hearty.
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Are you saying the C6 needs to be more than just a basic ceramic disc to avoid problems after warm up??
Rob
Yes.
I don’t know exactly how bad a basic ceramic capacitor would be, but for a couple dollars difference, I definitely think using a low temperature coefficient capacitor is worth it.
Especially if your synth is exposed to large temperature differences similar to what Sam described.
E.g. synth cold soaked in a van overnight at -10C, brought in and tuned at sound check before it can warm back up, then the room and synth heat up during the show. I wouldn’t be surprised if the inside of the case reached 50C when the power supplies are running at full (especially in a wood case which insulates pretty well).
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Great point @antoine.pasde2. I don’t typically have fluctuating temps, I haven’t noticed much in terms of detuning. But I know Sam’s said he did, so this aligns with that experience. Like you said it’s only a small diff in price, and even though it may not matter in some cases, this is one where it does! I for one am going to keep this in mind when I build future modules, and when I post BOMs. Thanks.
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Would this also apply to the AS3340 chip too?
So this is the capacitor that I bought:
https://www.taydaelectronics.com/10-x-1000pf-50v-ceramic-disc-capacitor-pkg-of-10.html
Are you saying that I should have gotten this one on Tayda’s site? Or should I have gotten something else?
https://www.taydaelectronics.com/capacitors/ceramic-disc-capacitors/10-1nf-50v-ceramic-disc-capacitor.html
The first one doesn’t have any temp specs, so could be anything – but is probably a class II ceramic, which are ceramics optimized for size but not stability, and primarily intended for decoupling/bypass use (where they work great). The second is a Y5P, which is a class II rated for use between −30 and +85 °C, and with max ±10% capacitance change over that range. Odds are the first one has the same specs, or slightly worse.
So none of them are great, but odds are you won’t notice much unless you tour Sweden in winter…
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Well my “Cave” only varies between about 5C and 20C year round so I am not going to worry at the moment…
Where I live it will range from -15C - 40C so it’s possible that I would have it in a parked vehicle when it’s -15C and have it taken inside where it will reach roughly 35C. Knowing this should I switch this capacitor to a different one and if so could you provide a link to one that you would recommend either on Tayda or Mouser’s site?
Thanks so much for the information! I’m trying to learn through Google searches and others on the forum so I appreciate it.
The cheapest 1nF mica at mouser is $3.56: https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/CD19FD102JO3?qs=sGAEpiMZZMtLiKaZgV7flZAQh3t86oTBhnL82ENMBV4%3D. So, you know, around 100 ceramics’ worth.
I don’t see anything on Tayda, the one that @ChristianBloch points to or this one: https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/CD15FA102JO3?qs=sGAEpiMZZMtLiKaZgV7flY0avx2494sswHD%2BL2sE9vE%3D should be fine.
Their temperature coefficient is listed as 0 to 70PPM/C, so for your whole -15C to +40C temperature range the capacitance (and thus frequency) would vary by at worse 55*70/1000000 = 1.085%
I think it’s worth the extra $3.50.
Edit: Yes that applies equally to the AS3340 and the CEM3340 or any oscillator’s timing capacitor.
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I’m not exactly an expert in unusual capacitors, but I suspect mica is overkill these days – there are fancy class I dielectrics out there that I doubt existed in the late seventies when the CEM3340 data sheet was written 
Mica is a lot more niche these days afaik (e.g. very high voltages, very high frequencies, …).
So for near zero drift, you can get class I C0G ceramics rated at 0±30ppm/C over -55°C to +125 °C, and they’re much cheaper than mica (at last for sane voltages, you don’t really need 500V caps in a synth ). Mouser has plenty of options, from ~$0.20 upwards for thru hole, e.g. Mouser No 594-K102J15C0GF53H5 looks like an ok choice. SMDs are even cheaper.
(and I should probably upgrade my own 3340 builds, btw 
)
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Here is some data, i hope it is relevant to the conversation:
1NF 0.001UF 100V 5% MYLAR FILM CAPACITORS
https://www.taydaelectronics.com/1nf-0-001uf-100v-5-mylar-film-capacitors.html
$0.03 / £0.023
0.001UF 50V CERAMIC DISC CAPACITOR AEC BRAND - BEST PERFORMANCE
https://www.taydaelectronics.com/10-1nf-50v-ceramic-disc-capacitor.html
$0.03 / £0.023
CD15FA102JO3
https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/CD15FA102JO3?qs=sGAEpiMZZMtLiKaZgV7flY0avx2494sswHD%2BL2sE9vE%3D
$4.82 / £3.65
It appears to me that unless you need it to operate in temps lower than -40c you shouldnt have issue using the mylar film? If so, what am i missing?
The ceramics look like they would operate just fine in environments -25c to 85c. Unless that capacitance change is still present in the operating temp as i assumed it wouldnt.
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Mylar (aka Polyester, PET) has higher temperature drift, but not sure how much exactly (I’ve seen numbers from +200ppm/C to ±5%, and the datasheets for the ones I usually use don’t specify it at all, what I can see). But better than class II ceramics, afaict.
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My understanding of the meaning of the “P” in the Y5P capacitor code is that the the capacitance at any given temperature within the operating range can be different from the capacitance at 25C by as much as +/- 10%.
So an exaggerated worst case example would be that at -15C it’s 10% above the 25C value and at 40C it’s 10% below the 25C value. That would represent a 20% change capacitance (and thus in pitch) from the sound check tuning right out of the truck and the heath of the concert.
That’s like a 440Hz A4 becoming a tree semitone higher C5. Definitely audible 
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The ceramics:
Y5P
Y=-30°
5 = +85°
P = ± 10%
The TCC for an Y5P is ± 10%
1000pf * 0.1 = ±100pf maximum capacitance change
So this capacitor at temperatures above or below 25° can be as high as 1100pf and as low as 900pf
You can probably just use a piece of wire. Or if you so prefer, something decorative:
Q: The analog synth circuit I’m building calls in the schematic for ferrite beads on the power rails, but it doesn’t give any further information. What kind of beads should I use?
A: Pick some that will look nice on the board, maybe in a colour that goes with the solder mask. Your local craft supply store should have a good selection of decorative beads, like these glass ones I got in a clearance sale.
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has anyone got a good source for Blank black circuit board, unprinted for use as a panel instead of aluminium ??
Check out this thread i made earlier about my experiences.
It shows you how easy it can be to make your own custom boards. You dont have to be content with just a plain black board that you have to drill etc. Just CAD them holes and add them graphics.
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