29 May
2007
29 May
'07
3:17 a.m.
pure data is something i have been wanting to look into. i suppose my reason
for the spice thing is that one of my hobbies is building and modifying old
valve amps (not a huge success rate at the moment though, but getting
there... stupid old power transformers dying on me...). i know that spice
will not give an accurate sound of a real valve, but it would be really
handy to hear *changes* with circuit modifications on a real signal. things
like frequency response are pretty straightforward i suppose, but what about
things like sag and the effects of negative feedback? bit harder to judge
from the schematic if you are a beginner like me :) i'll have to have a look
at your spice thingy when i get home (my machine here isn't set up for stuff
like that... yet :).
off topic (from my off topic previous post...): does anyone know where to
get *good* spice models for valves/tubes? especially working with oregano (i
tried geda but it keeps crashing on me). also good transformer models (i
know these can be done somehow with subcircuits, but as i said, i'm still a
beginner. i just want some basic 4k/8ohm single ended and push-pull models
for basic circuit building.
thanks
porl
On 29/05/07, Robin Gareus <robin(a)gareus.org> wrote:
porl sheean wrote:
> Hmm. An interesting project might be hacking
SPICE into being a
> kind of a deconvolution engine,
> to build a WAV impulse response file of a circuit. Then you could
> use that IR to "play" through the circuit using JACE or similar.
i have been dreaming of this for so long :) i
thought about it the
other way though, using a 'custom' wave shape as a function generator
in spice itself. would be very slow this way though.
I've been dreaming about a /jackifiying/ spice ;) - I spiced up my
Pfingst Montag by added a libsndfile voltage-source to ng-spice. - For
simple circuits it's not too far-off real-time performance: it takes
about 4 seconds to simulate 1 second of foxxtone at 48ksps over here.
Now it's Tueday and using a IR seems the way to go... simulating the
foxx effect alone is not trivial. Based on the posted schematics, here's
a preliminary http://mir.dnsalias.com/_media/wiki/foxx.oregano.gz - try
yourself..
the good news about doing this though is that you
don't have to
(unless you want to) emulate everything about the circuit, just the
signal path. this would simplify and speed up the calculations
somewhat.
I've started to document the spice patch at
http://mir.dnsalias.com/wiki/spicesound - the code's barely a few hours
old and highly experimental. NTL, it's already allows to process spice3
netlists reading and generating wav file(s).
robin
PS. pure-data is more fun than this!
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