[linux-audio-dev] [ann] unmatched - a LADSPA amp tone

[Steve Harris]

On Tue, Oct 22, 2002 at 09:55:07AM -0700, Paul Winkler wrote:
> I recently acquired my first vintage amp - 
> a '63 Gibson GA-30 RVT in very good shape.
> It's pretty versatile and doesn't sound quite like anything else
> I've played. I'd be happy to donate some impulses, with various 
> mics / positions and amp settings, if somebody can tell me a good way 
> to do it. How do you generate the impulse?  (I've tried simply creating
> a sample with 1 frame at maximum followed by zeroes, but this seems
> not to make it through the D/A conversion - it comes out as dead
> silence.)

OK, well an alternative, for EQ readings is to push whitenoise though.
This doesn't work too well for convolving though, if you want to make it
compatible with a convolver then I suggest you make a sine sweep (10
seconds long, 50Hz to 20kHz should be plenty), and record that. You can
then deconvolve the recording with the sweep and you are left with an
impulse.

I've not seen the DA converter problem you mention before, that's
interesting.

> I also have some very odd impulses lying around somewhere if
> I can find them - made by popping balloons in and around
> some 20' by 5' steel tanks that were in the basement of
> a converted industrial building I used to live in.

Mmmmmm. Yeah, that would be cool if you can find them. We have some old,
linked salt water storage tanks at work that desperatly need impulses
taking. The problem is that its really damp down there, so I didn't want
to take monitors down, and I dont have any acceptable mics that dont need
phantom power. I never thought of a baloon, I was going to try a kids cap
gun.

I have a bigish library of impulses, but I can't remeber where most of
them came from, so I'm reluctant to release them.

- Steve