Nava v1.0 BOM [5/18/16 IMPORTANT BOM UPDATE]

Discuss Nava construction and related issues
  • DrRek wrote:Hey anyone have a link for a 15VAC 1000mA psu?
    http://www.rcs-elektronik.com.pl/index. ... ad-zmienny
  • Gonna start another Nava build, and was looking thru the BOM.
    Whats the deal with the 4.7k resistors, with a little wierd temp coeff? http://www.mouser.se/Search/ProductDeta ... -CFR16J4K7

    Why are these there instead of "normal" 4.7k resistors? Does it even matter?
  • AonFluX wrote:Gonna start another Nava build, and was looking thru the BOM.
    Whats the deal with the 4.7k resistors, with a little wierd temp coeff? http://www.mouser.se/Search/ProductDeta ... -CFR16J4K7

    Why are these there instead of "normal" 4.7k resistors? Does it even matter?
    No it doesn't matter, I think this part has been choosed in the Mouser BOM because the original one wasn't available anymore. Any 4.7k resistors will do.
  • Ok, thanks for the answer!
  • Just got to the handclap and found I only had 1 .1uf film cap left... because the build guide STILL has C48 listed as film instead of ceramic :roll: :|

    someone should fix this
  • Hi there,

    it seems that the 160KOhms resistors (CCF07160KGKE36) are currently out of stock at mouser :
    http://www.mouser.fr/Search/ProductDeta ... 7160KGKE36
    (1/4watt 160Kohms 2% Rated to 1/2watt)

    Do you guys know if the following ref could be a correct replacement ?
    http://www.mouser.fr/ProductDetail/Vish ... speA%3d%3d
    (1/4watt 160Kohms 5% Rated to 1/2watt)

    Is the tolerance crucial for those items ? (RA9F, RA10F, RA11F, RA12F, RA13F)

    Thanks!
  • It's the resistor ladder of the DAC. You want it as precise as possible to have the closest linear proportion between your analog output value and the digital input value.
    It's why at the start Vincent has you measure 5 x 10K resistors that are as close as possible to the 10K.

    Now, I don't know how critical it is. I measured some of my precision resistors before soldering and I don't think they where that "precise". I guess if you get a bunch of 2% metal resistors, just pick out the ones <0.3% to the value. Anyway they cost next to nothing.

    Mouser still has plenty, just go for a different brand: http://www.mouser.be/Passive-Components ... z0Z1yzbpod

    EDIT:Looking back at my BOM, the resistors for the DAC ladders were 0.1%.
    http://www.mouser.be/Search/ProductDeta ... 55C1603BTR
  • Hi,

    the 50V 390 pf capacitor is sold out at mouser, is it also possible to use 330 pf?
  • e-licktronic wrote:jvq,

    C48 is a ceramic capacitor so the total of film capacitor is 7pcs
    BOM updated. R82EC3100AA70J reference deleted

    Thank you for your help

    Best regards,
    e-licktronic
    C48 is in the tutorial still a film capacitor...?