Some thoughts on one of the places where digital tech fails to live up to some of the more grandiose promises made for it…
Digital does linear very well. So things like summing and EQ processing tend to turn out very much as expected (and presumably desired — unless one is looking for mojo — but then he’s not really looking for just EQ).
But audio signal compression is not a linear process. And some feel that analog hardware does it better (or can have more mojo); a technical case can be made. That said, and while I do use an analog compressor in my input chain, I also have some compressor plugs that I think work very well.
Now… circuit (and tape) saturation simulation is an even more mojo-intensive sort of endeavor, it seems to me.
An amp driven into saturation by an electric guitar forms a very complex, even chaotic system with many alinear, hard-to-predict performance characteristics.
And the mojo/chaos isn’t all in the amp’s circuitry, either — and it’s not all about simple amplitude-driven saturation.
As the dynamic level and as the frequency of the signal put out by the guitar changes, it changes the impedance relationship with the amp, making — particularly at sub-saturation and low-saturation levels — that relationship extremely dynamic.
Depending on the guitar, amp, settings, and playing style, relatively small changes in playing can make very noticeable changes in the sound coming out of the amp.
When a knowledgeable, sophisticated player knows his guitar and his amp and sets it accordingly, he can often capture a wide range of timbral expression without even touch a knob.
That’s why you sometimes here folks say, The tone is in his fingers.
But if the guitarist didn’t know how to set up the relationships between his guitar to make the most of his playing dynamics, the sound of the amp might sound almost as undynamic — and uninspiring — as many amp sim presets.
And one of the main problems is that that highly dynamic impedance relationship that a guitar and amp have is not mirrored by the dynamic relationship between the guitar and the analog front end of something like a computer AD or the AD in the POD.
And once the signal is digitized, that dynamic is carved in stone, except for what little chaos one can pull out of feedback from live monitoring. You can get some typically very limited, highly undynamic feedback from your EG picking up the acoustic energy coming out of your speakers — but it is nothing like the highly complex, highly dynamic relationship of an EG going into a conventional amplifier, where there is some form dynamic signal continuity all the way from the pickups to the speaker.
This is a subject that is fresh for me because, last night, after an uncharacteristically hot day in an apartment where the heat lingered on, the last thing I wanted to do was fire up my Blues Jr tube amp and the 24 channel board I normally use to route my live tracking and cue mix through. So I pulled out the POD XT that a friend left here a few years ago. I’ve now spent a total of maybe 8 or 10 hours playing with it and I know it pretty well.
I was able to get some OK-ish sounds. But I kept feeling like I was fighting both the unit and my interface’s direct monitoring latency — not a huge amount of latency, by any stretch, probably about 4 ms (AD/DA into AD/DA — but not routed through the computer). Still, I could sort of put myself in a head space where I ‘played ahead’ enough to make it work rhythmically, for the most part.
But the sound, while not bad, was just not anything like the glassy (but noisy), highly dynamic tones I can get out of the Fender amp.