I know this is going to really show my alarming lack of circuit knowledge but here goes.
How important is the % tolerance and resister wattage levels? I’m guessing pretty much everything kosmo related is fine in the 2% tolerance range and at 1/4watt. Unless stated specifically, which I cant find many instances of.
Summary here:
Many if not most DIY designs are fine with 5% carbon film, but if you stick to the common standard 1% 1/4 W metal film you’re set for almost everything.
(where lower tolerance is needed, you can often hand-match 1% resistors)
I asked at my local parts store and they said “Is this for test equipment?” and I was all “Do I look like Hainbach?”
XD
If you look at (for instance) the BOM for the 1222 Performance Oscillator for most of the resistors he specifies:
Resistor (preferable metal film 0.25W)
There’s no tolerance explicitly stated, but metal film 0.25W is most commonly 1%.
For four resistors he specifies
Resistor (preferable metal film 0.25W) precision… watch vid
Those need to be matched to one another to good precision in order to have the octave switch in tune. You can buy “precision resistors” with say 0.1% tolerance… or you can go through a bag of 1% resistors and pick out four that measure the same with your DVM.
It depends but mostly you’re fine with all 1/4W 5% or 1% parts. Thick film not thin film because you will pay way too much for thin film. Unless you really need them. Here is a paper on the differences. And yes, you are building instruments and sometimes, in certain places, low tolerance high precision parts are needed. Log converters, wide operating frequency oscillators, long hold times, matched performance of multiple circuits, these circuits are pushing the limits of off the shelf parts.