Digital Modeling of Tube Amp Distortion

[guitician]

I'm curious about what logic they use to come up with the effect of cloning a vintage amp or effect using DSP technology. I think that it is flawed because with a vintage pedal wouldn't they have to make it sound as though I was playing my vintage pedal into my Hi-Fi? Shouldn't they have output modes that tone shape conforming to whether your playing into a PA or a guitar amp? And with amps, couldn't they add a "Speaker Tone Shape Mode" to compensate for what type of speaker you using.

[Mark Hammer]

The first step is always to describe the phenomenon you wish to emulate. At the moment, I doubt that anyone has a full enough accounting and description of ANY tube amp to permit flawless replication in software. That's not to say it is impossible. Actually, we're getting closer. We're just not there yet.

I am always reminded of the comments that journalists made about recording technology of the time when Thomas Edison was doing the county fair circuit with his wax cylinder recording machines. To their ears, the wax recordings sounded "identical" to the original voice being recorded. Of course part of that was due to it being the first time that an attempt had been made to record sound. That it resembled the voice in *any* way was persuasive enough for them. With time, people recognized the difference between wax cylinders and the "real thing" and in describing those differences, advances in recording were made. Of course, people in the 1950's thought they had it nailed, compared to 1935 or 1920, and now we know different.

So, modelling of digital amps is getting much better. Is it there yet? No...but it's getting closer every day.

[Steve Conner]

And, I've seen digital modelling products that do have these "speaker tone shaping modes" and so on. I can't remember which one it was, but I'm sure I saw something that let you turn the speaker model on for playing through a PA, and off for playing through a guitar amp.

[JoeM]

And, I've seen digital modelling products that do have these "speaker tone shaping modes" and so on. I can't remember which one it was, but I'm sure I saw something that let you turn the speaker model on for playing through a PA, and off for playing through a guitar amp.

There's something like that on my Pod XT.

[R.G.]

So, modelling of digital amps is getting much better. Is it there yet? No...but it's getting closer every day.

This reminds me of one of my rare public events. I'd been introduced to a group of professional musicians and expected questions about this, that, or the other effect. Instead, as I stood there with the mike, the first question was "How soon will we get good digital emulation of tube amps?"

My reply was "Well, digital and DSP technology is improving every day, and I'd say that good DSP emulation of tubes is just around the corner - just like it has been for the last 30 years."

[Steve Conner]

Here's a random thought: Maybe replication and emulation is the wrong way to go about it.

It might actually be easier to go back to first principles of frequency response shaping, non-linearity, compression, "touch sensitivity" and so on, implement these in DSP-friendly ways, and in that way you could make a digital amp that sounds and plays great, even if nobody can quite put their finger on what classic amp it's supposed to be "emulating".

I think in general, companies like Line6 give the market exactly what it wants. Remembering that the market consists mostly of bedroom guitar heroes and wedding band guitarists, and true corksniffers are a minority.

I could quit my job tomorrow and build a digital amp that you'd prefer to a tweed Deluxe in blind tests, but my inner businessman tells me nobody would buy it and I'd go broke, because it's not what the market wants. They want 100 mediocre amp models and 100 trashy effects in one low-cost box, with a budget of $5 for the DSP chip.

I'd love to try the new Fractal Axe thing but it's hell of an expensive.

[guitician]

Creating For the Market

Yes Steve, I think that is exactly why DSP tube emulation technology is the way it is. Back in the early fifties, they weren't looking back and trying to "Get it Right", all they are doing now is making a marketable item.

Is there a market for extremely high quality tube emulation? Can they "Get it Right" throwing tens of millions at the task? I'd bet, if while they were developing tube emulation, they held off selling it for 10 years or so, until they "Got it Right", then their current sales would have been much greater.

[Steve Conner]

Another pet theory I have is that modelling amps might suck because the good DSP programmers are too young to appreciate good tone. And if you're old enough to appreciate classic tones, then you might be too old to understand modern DSP. They probably grew up listening to terrible 90s metal, like me.

Having said that, check this out. Welcome - Axe FX Standard - Axe FX Ultra - Atomic Reactor FR - Axe-Edit - Fractal Audio Systems - Atomic Amplifiers

Metal players seem to love it, which kind of supports my theory...

[guitician]

Ha, what do ya know, someone's trying to sell to a niche market. Auditioning it from my PC is not going to sell me though. I like how he sells tube amps to play the emulators through. That's gotta tell ya something....Id like to hear them in person to see if they've got something. To me an emulation should sound fantastic though the PA system, like keyboards and mics. And I'm not talking clean tube sounds either. I'm talking dimed Marshall, Boogie's, Dumble Etc.