Welcome to the forum.
borla wrote:So, when I first started Guitarix, I was wondering about amp impulses and had no idea where to put them in a "complete" signal chain like Tubeamp -> Tonestack -> Cabinet (I think it's best between Tube and Tone).
Well, the amp impulses are IR-files from Amps, without the influence of the speakers. They may be best use instead the tonestacks.
borla wrote:And if so: How can one do an amp IR without it's tubes or speakers? Or are they doubled when combining an amp IR (which already includes tubes- and speakersound) and the Guitarix tubeamp and cabinets?
IR files are mostly done by comparing sounds and de-convolve the difference. But, the non-linear part will never be part of this process. So, at least, a IR-file is a EQ curve which represent the Spectrum of what ever you could imagine. This could be a Church, a Cup, or a Floor, from which you cover the room response (Echo and reverb been linear operations), or, even a amp, a speaker or a MIC, from which you cover the Frequency Response.
But, to be honest, they arn't done by me, I've found them floating around in the Net, just striped them down a bit.