4-Pole Mission Substitute Components

as alternative for C9, C15, C22, C26?

The listed farnell part (1694115) doesn’t seem to exist (typo?).


The Digikey part listed for these caps also seems to be incorrect:
(it’s a ceramic cap, not a polystyrene one).


The Farnell polystyrene part you mention is correct. Ceramic can be used too, as long as they have a tolerance <= 5%.

Ah, cool, thanks pichenettes.

More questions, I’m afraid:

1. Could I use a 82 or 120pF ceramic cap in place of the listed 100p for the filter board parts C4 C16?
There’s this part, but the 100p version is out of stock (trying to get all the ceramic caps from the same place).

2. For C11, C12, C24, C25, would 470 or 680pF be a workable substitute for the listed 560p?



@pichenettes can I be a bastard and push you for an answer on these last two questions? Sorry to be pushy, just wanna put in an order this evening so there’s a chance I’ll get the components before the weekend.


Yo Alex,

i can well include these Caps in my FridayToDeploy™ Reichelt Order and ship them to you… probably to late for this weekend but matching :wink:

The answers are: Yes and yes.

Just for clarity, is it worth checking the Farnell reference for C9, C15, C22, C26 in the BOM? I’ve tried searching the UK Farnell site, and Onecall (the education portal for the company), and neither list a component with the reference 1694115. I think 9520031 is the correct code.


The Farnell polystyrene reference 9520031 is correct.

@pichenettes thanks very much. Apologies again for being an awkward customer. Do you think it’s worth me taking up fcd72’s kind offer, or will the substitutes I suggested be for practical (audible) purposes identical, do you think? Would I be better using the lower or higher value caps?


Use lower value caps, I highly doubt the difference will be measurable.

@pichenettes thanks again!


Sorry, me again :frowning:
Are ‘NPO’ and ‘Y5v’ type ceramic caps both OK?I realised I’ve bought a mixture of the two types.
Sorry for the stream of stupid questions.


No problem with those.

@pichenettes thanks again!
Orders on their way now. Looking forward to a weekend soldering (though my girlfriend probably isn’t looking forward to me soldering all weekend). :wink:


Finished mine at lunchtime :slight_smile: my parts arrived pretty quickly. Just need to do all the voltage checks (done a few and they were good) before putting the chips in.

There’s something that make me wonder about the Mouser BOM for the 4PM Edition:
Why are there 33.0k and 33.2k 1% precision resistors in the same BOM? Both are the same technology and bear the same power.
Is this distinction supposed to be the same in the Dual SVF board or is this simply incidental?

You can use 33.2k in place of the 33.0k. Not the other way round! The pole-mixing resistors need to be as close as you can get to 100 / 3.

Or you could buy a batch of 5% 33k resistors and measure them to find the closest ones to 33.333k :wink:


You won’t find any :slight_smile:

Resistors are tested out of the production chain. Those within +/- 0.1% are labelled as 0.1%. Those within 1% are labelled as 1%. The rest is labelled as 5%. So the distribution of values of 5% resistors has a “gap” in the middle.