About Digital Gear

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1. Foreword 2.About music 3. About rock 4. About sound 5. About mixing 6. About guitarists 7. About tubes 8. About pedals
9. About digital 10. Ab. compression 11. About saturation 12. About filters 13. About delays 14. About chorus 15. About switching 16. Synthesis

If you are reading this page, you certainly know that Rockman gear is purely analog, and that Tom Scholz doesn’t like digital processors.

By coincidence, my initial specialty as an engineer was… digital signal processing - DSP. I will always remember this teacher warning us, when we had to choose, for our last year in our engineer school, between the “analog electronics” and “digital processing” classes: “You will learn everything with analog electronics. Digital may seem fancy ‘cause it’s new, but you won’t learn as much.” That was in… 1984.

Our teacher was right. Digital processing is computer science, while we were in fact interested in signal processing. Programming lines of code versus creating circuits and real devices… Hopefully, my father had taught me the basis of electronics, and this basis is still useful today. I graduated in 1985, and what I have learnt about computers 22 years ago is completely outdated...

Anyway, while DSP was still a young domain in the eighties, it is now mature, and we can now find convincing music-oriented digital processors. Like the tubes vs solid-state debate, the question “which one is better” will soon be over. But it is not over yet, strange as it may be. The “perfection” of digital processing has revealed several severe drawbacks, amongst many qualities. These drawbacks can be cured by increasing the programs and algorithm sizes, and the technical capacity of the processors: more bits, more bytes, more RAM, etc…

But digital processing is, unlike analog processing, based on something that will always keep it apart, and therefore make a difference: quantization.

As long as digital processors are asked to act in a linear manner, they can do an excellent job if the gear is not too cheap, especially with impulse response and convolution approaches. For some non linear processes, it is possible to get excellent results, provided that the problem can be deciphered into algorithms or formulas. It’s only a matter of money and programming labour.

But that’s where the problem is: musical gear is based on hundreds of non-linear behaviors, all these defaults of the components that make analog gear sound “natural” (one can wonder what can be natural in a chain of guitar amps and effects, but why not…).

You can build a mathematical model for each non-linearity: clipping, compression, etc… But you cannot create a mathematical model of a device which has a different behavior each time the signal level changes, especially if these behaviors evolve continuously. You can of course imagine an algorithm with 4, 6, 8 different behaviors depending on the signal strength. You can dream of a processor capable of 1024, 2048 or more different behaviors. But you will always be limited to a certain number of cases, because the numbers handled by the computer are quantized and not continuous. It’s not a problem if you can find a mathematical law linking these 1024 behaviors – a computer can do that. But in the real life, there is no law to describe the individual changes of all the components of a complex analog circuit.

Is it really critical? Well, as long as digital gear will only aim at copying analog stuff, it will certainly be critical. The real problem, and the only question, is “why can’t we quit copying, and why don’t we create new guitar sounds based on digital gear?”.

I don’t have the answer. All I can say is that digital signal processing has brought two things only to the guitar players: pitch-shifting (harmonizers and whammy pedals) and reverbs. You can read all the webpages you want, the rest is purely analog gear duplication...

If you consider that pitch-shifting existed much before the digital era, by the means of tape-speed control, and that reverb is probably the only effect that doesn’t need electronics (it will give you a good reason to enter a church if you don’t see what I mean…), what did digital processing bring us? Nothing, or nothing really new.

Tom Scholz has a sentence that summarizes perfectly the digital processing subject: there’s nothing digital stuff can do that analog gear cannot do, and analog is anyway easier to control and design. And that was exactly what my teacher tried to tell us when I was a student!

OK. Back in the eighties, when SR&D was creating and building Rockman gear. Remember that Tom Scholz is not totally opposed to digital technologies: Tom has created samples-based drum machines before they were actually available as commercial items, and if you read carefully the Boston records sleeves, you will find that Lexicon reverbs are used for the vocal parts…

But after reading what I write in 2007, why would have he wasted time in the eighties with digital gear for the guitar players?

Copyright Rockman.fr 2007