Re: [LAD] simulating analog audio devices

Pieter Palmers wrote: > Erik de Castro Lopo wrote: >> Robin Gareus wrote: >> >>> hey LADs. >>> >>> For those of you who have not followed the 'fuzztone' thread on LAU. >>> I'd >>> like to announce a /cool hack/ to ngSpice that provides soundfile I/O >>> capabilities. - it's more a LAD than a LAU issue anyway. >> >> This is a CoolAsAllFsck (tm) hack as far as I am concerned. >> Congrats. >> >>> Simple tests sound rather promising; but my fuzztone experiment is not >>> really satisfying yet. well, maybe it's just meant to sound *that* >>> weird >>> ;) >> >> I used Spice as part of my engineering degree and also in jobs later, >> but my memory of this is definitely hazy. >> >> However, my memories of how spice works is my discretizing the >> differential equations that describe the components. I believe >> the specification of the time step determines how fine grained >> (in time) a grid will be used for operating on the diff equations. >> >> One thing you might have missed is matching up the samplerate of >> the input file with the time grid of the spice calculations. You alos >> want to be *really* careful about how you interpolate >> the file data to spice sample rate. Please, please, please, do >> not use linear interpolation. Secret Rabbit Code is probably the way >> to go here.

> All spices I use (although this excludes ngspice) have an option to > force them to calculate the response at specified timesteps (along > with the ones they need for accuracy). In this case it seems obvious > to set this timestep to 1/Fsample.