28 Oct
2002
28 Oct
'02
7:19 p.m.
On Mon, Oct 28, 2002 at 10:37:18PM +0100, Tim Goetze wrote:
i'm sure frequency responses and Vin/Vout mappings
for common
amp tubes (EL34 comes to mind, too) would be very helpful, but
can i ask you to take a look at
http://quitte.de/driven.gif
first?
it shows my badly-driven fender amp's line output (top) vs. the sine
wave it was fed at the same time. i'm wondering how come the output
overshoots every time the input crosses zero. trying to model this
behaviour into a waveshaper, but i'm a bit lost on the physical laws
that rule here.
looking at the distorted signal it look to me like an amp that is clipping,
but it's power supply can't maintain the voltage (eg. relatively high
impendance on the powersupply/series resistance). While +ve or -ve side of
the output pair is used it drains the capacitor from the power supply, hence
the exponential slope from 'spike' till drop.
Frank.
--
+---- --- -- - - - -
| Frank van de Pol -o) A-L-S-A
| FvdPol(a)home.nl /\\ Sounds good!
| http://www.alsa-project.org _\_v
| Linux - Why use Windows if we have doors available?
