OT: websites about tube emulation

Have you got links to websites that explain in a simple way the emulation of a guitar amp, maybe articles about line6, or by line6 team themself?
The workflow, how it does work and such etc etc.
I'm surfing but I've found nothing good.

cheers

I may be wrong but i think i remember reading some article(s?) at the Simulanalog site.
 
One thing you may be interested is the basics of emulation.

When I was studying "signal theory" in my enginering course I studied the "signal convolution" and "Fourier Transform"...

Never payed much attention to that until convolution reverb plugins started to apear... then all maked sence.

The basic concept behind emulation is simple:

A) capture the signal of the source you are trying to emulate (lets say an engl)

B) represent that signal (a very complex analog one) using mathematical formulas, so that the properties/information of that signal can be represented/stored with simple known math forms. At this point you are going to go digital because only a computer can do such types of calculations.

2 notes: *When going digital there will be some erros (information lost). Also the quantity of infomation stored in 16 bits is gonna be smaller than at 64.
*The representation of the original signal through "Fourier transform" will not translate in an exact interpretation but in a VERY close one.

C) combine the new signal (lets say a clean guitar) with the mathematical represented one using "signal convolution"

thats pretty much it in a simple way...

take care
 
wow thanks VH100R
really interesting stuff ;)
I was wondering about this: if you say they convert to 16 bits you loose a lot, why don't they (amp manufacturer) make an amp without converting to 16 but use a 64 bits information.
Maybe it's expensive keeping it at 64 bits.
And what about capturing the sound of an engl: if I use convolution, as Mutant explained months ago on this forum (if I'm not worng), I just reproduce the speaker sound, movement of the air, mic "colour", preamp "colour", not distortion coming from the amp.
Can I capture, let's say, my favorite settings of my amp and then apply this to my clean guitar and make it sound distorted without the need to play through the amp? with convolution you still need the amp or a distortion box.
oh well I'm a noob about this stuff, I have to study a lot physics :)

chees
 
some of the line 6 team went on to form damage control don't forget.
 
wow thanks VH100R
really interesting stuff ;)
I was wondering about this: if you say they convert to 16 bits you loose a lot, why don't they (amp manufacturer) make an amp without converting to 16 but use a 64 bits information.
Maybe it's expensive keeping it at 64 bits.
And what about capturing the sound of an engl: if I use convolution, as Mutant explained months ago on this forum (if I'm not worng), I just reproduce the speaker sound, movement of the air, mic "colour", preamp "colour", not distortion coming from the amp.
Can I capture, let's say, my favorite settings of my amp and then apply this to my clean guitar and make it sound distorted without the need to play through the amp? with convolution you still need the amp or a distortion box.
oh well I'm a noob about this stuff, I have to study a lot physics :)

chees

Zoom developed a new chip with 32 bits specially for the new G series. I haven't tryed their G2 yet but when I get the chance I'm gonna get me one to try out.

As far as I know they are the only ones using 32bit right now.

The thing is... THEY developed the chip (alot $ invested on researching). Most manufactures just go to catalogs with already available chips and use them according to their projects.

It is more easy to wait and let companies like Texas to develop and research rather then developing your own. Which makes sence... since they are looking for profit. So that answers your question why don't they go full blast on 64 bits. Oh and 64bits means having A/D and D/a converters ready to work with those bitrates too, so more R&D on those suckers too.

When I first read this forum about how to capture cabinet impulses the first thing I though was why don't these guys capture the whole amp instead?

I think that if you can capture the poweramp+cabinet+mic+room (like you did with your cab impulse) you can surely capture the preamp aswell.

then you'll capture the full package: preamp+poweramp+cabinet+mic+room. get the picture?

From what I understood you started your capture thru the loop, feeding the signal from the computer before the poweramp right?

then all you need to do is capture the entire amp, feeding the signal thru the input. I think that if your cab impulses sound better than anything that has been done by pro companies, the entire amp emulation will be better to. This is what Simulanalog dude must have done... And while not being the best amp for metal I still think his emulation sounds pretty damn good.

Since you guys already have the know how to make really good cab impulses, and almost everybody here has a good arsenal of high gain amps you can all make history capturing those amps with excellent results.

I'm hoping some of you impulse makers on this forum can try that, and I am looking very curious about the result.

keep in touch

take care... Luis G:kickass:
 
I feed the poweramp section of the amp with a sine wave, so I basically bypassed the pre section, I recorded that sound coming from the speaker then I deconvolved it later in my daw.
I did a test using the distorted channel instead, but it didn't work, with impulses you can't recreate distortion as mutant said.
 
I feed the poweramp section of the amp with a sine wave, so I basically bypassed the pre section, I recorded that sound coming from the speaker then I deconvolved it later in my daw.
I did a test using the distorted channel instead, but it didn't work, with impulses you can't recreate distortion as mutant said.

why it didn't work? what results did you got? It should work, since the principle is the same... humm. anyone tryed that (feeding the input)besides you?
 
so what you mean?
those distortion pedals got tubes if I'm not wrong, so you're basically telling me that is better stop thinking about emulation and switch back to the classic old formula?

i'm not sure where I was going with that.
 
hey kaomao

what kind of results did you get?

When feeding the input of the amp did you take in consideration level/impedance mismatch (as in a reamping situation)?

This is the only thing I can think of... and the fact that MAYBE the Voxengo software code can't handle the calculations needed with a highly complex distorted signal...
 
No I didn't take anything in consideration about level/impedence mismatch.
I was a noob about convolution and still I am.
anyway it doesn't work.
If you plug a cable into the input of the amp, and then playing the sweep from your daw back to it, deconvolving this resulted file, you won't get anything distorted.
here we talked about convolution