Axe-Fx 2 Amp Block Building Blocks

El Tel

New Member
Hello all,

I have a fairly fundamental question to ask about the construction of the various amp simulations, in my case in the Axe Fx2, although I suspect the question is applicable to all Axe Fx equipment.

My mind tends to work in pictures not numbers so I’m trying to produce an amp block virtual schematic to help visualise where each adjustable parameter acts. This will be along the lines of the ‘simplified diagram of the AMP block’ that appears in all Axe-Fx manuals, Wikis.......etc.

Do all virtual amps start from the same place i.e the same set of building blocks which then have their parameters adjusted to model the particular amp. By way of example of what I’m getting at, if I took for instance the ‘Brit 800’ model and adjusted all the settings on that model to those of the ‘59 Bassguy’ would I end up with a ‘59 Bassguy’ or do all the amps differ when you get down to the code .

Thanks in anticipation,

El Tel
 
Hello all,

I have a fairly fundamental question to ask about the construction of the various amp simulations, in my case in the Axe Fx2, although I suspect the question is applicable to all Axe Fx equipment.

My mind tends to work in pictures not numbers so I’m trying to produce an amp block virtual schematic to help visualise where each adjustable parameter acts. This will be along the lines of the ‘simplified diagram of the AMP block’ that appears in all Axe-Fx manuals, Wikis.......etc.

Do all virtual amps start from the same place i.e the same set of building blocks which then have their parameters adjusted to model the particular amp. By way of example of what I’m getting at, if I took for instance the ‘Brit 800’ model and adjusted all the settings on that model to those of the ‘59 Bassguy’ would I end up with a ‘59 Bassguy’ or do all the amps differ when you get down to the code .

Thanks in anticipation,

El Tel
Many of the tricks used by FAS to model the amps involve emulating the actual circuitry and most of this is hidden from us, but of course you can tweak one to sound more like the other.
 
Changing the settings would get you closer, but not all the way there depending on what amp you attempt to modify into which other amp.

Tube guitar amp building blocks are...

Various gain stage(s) and cathode follower stage(s) with inter gain stage padding and filtering, tonestack, reverb/vibrato/tremelo FX in some cases, phase inverter, power section and transformer, and power supply. The amp models also appear to have various dynamics processes included as well.

Cliff thankfully gave us the ability to modify a great many of these parameters, but not all, i.e. we do not have access to every plate/cathode resistor and bypass cap, coupling caps, to the actual tonestack components (though we can center it etc), though for practical purposes which include the fact that the cab/speaker has a huge impact on the final sound, you can for practical purposes create whatever you like.

Most tube amps are more similar than different, so I'd "guess" that Cliff has a number of building blocks similar to the above that he can place and modify as needed to create an amp model, so some amp models differ a bit and others don't much.
 
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Thanks for your reply. It sounds like my plan is basically sound based on all the models having the same basic building blocks. I’ll go ahead and produce my diagram and will share when completed, just in case anyone else finds it useful.
 
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