adc dac buffer
but all i have to do for the dax is single ended to balanced conversion and back
well thats why im doing a buffer for the inverting input
i dont want to split an amp into two channels, so doff the diff to unbalanced i would have spare amp
also the shit has ferrites on the inputs, and diodes to rail and ground (its designed for single supply right now)
so that maybe adds some noise
Posted by renesis at 18:35 | permalink | 0 comments
yeah need to see the circuit
because plent of systems do the same shit using way less and measure really well
usually adding amps doesnt help unless theyre really expensive amps
it depends
commercial layouts have to pass emc
and esd, so theyre usually pretty hardened
its both
heh, immunity testing active speakers and guitar amps is great
they scream
they wont
unless youre running 40dB of headroom
sure
they can
i think its an arduino adda buffer
but im doing same circuit for some hax at work
so i basically did it for him
Posted by renesis at 18:30 | permalink | 0 comments
anyway, you avoid loops and keep shit away from digital/control signals and shit typically works out well
tons of audio stuff is grounded pretty shitty and still manages to get badass performance using the right parts
good layouts tend to be more consitent about it
if you have an adc ground goes to there then across to the digital ground and etc etc
do oyou have a white paper or not
Posted by renesis at 18:25 | permalink | 0 comments
then its easy to match impedance
nice
the balanced to signel ended converter on the bottom
second stage is normal unity diff amp
first stage is just inverting input buffer
oh, audio
diodes and ferrites are emi/esd hax
i usually chop off my ground planes and bring them to the star ground seperate
like, leaf ground (stolen kevtris term)
why no
sure
you dont bring audio grounds to other ground until the end, at the star ground
?
you have to join them somewhere mofo
Posted by renesis at 18:19 | permalink | 0 comments
https://www.circuitlab.com/circuit/75m8fd/screenshot/1024x768/
their large png is not large enough
okay so prob with diff amps is everyone does them with matched resistors, because easy + because bias current is canceled
and in specs for diff inputs, youll see these circuits labeled 10K + 10K or 20K diff input
but when you actually math that shit out, you pull like 3x the current on one of the inputs, so to the source, youre not a balanced pair of 10K inputs
so like, you could take the inverting put side and triple the resistor values relative to the matched ratio resistors on the noninverting side
and you get matched impedance, but input bias current is meh
https://www.circuitlab.com/circuit/75m8fd/screenshot/1024x768/
so i did this, because dont want to use one amp for two channels (because crosstalk) so might as well use the other amp and a puffered input for the inverting side
Posted by renesis at 18:14 | permalink | 0 comments
its a fucking dip avr you dont need a devboard
just solder shit to it deadbug or plug into a solderless breadboard or perfboard the shit
Posted by renesis at 13:34 | permalink | 0 comments
19:30 < reza____> they obviously don't know how to use the built-in pullup resistor
built in pullups are shit
the resistance is too high and the tolerance is just silly
theyre good for fucking around but i wouldnt use them in a layout
Posted by renesis at 08:49 | permalink | 0 comments
super dimensional radioctivity
you know im not even sure how to interpret that
Posted by renesis at 03:48 | permalink | 0 comments
office supply places
transparency paper, or projector paper
art stores will prob have something similar
open the boxes and check, sometimes the paper has a powdery layer, dunno how much that affects things
Posted by renesis at 01:02 | permalink | 0 comments
i think its just overhead projector paper?
teachers use it and projectors so they dont gotta be writing on a white board with their ass facing the class
Posted by renesis at 00:43 | permalink | 0 comments
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