Stompbox Cookbook and digital question.

[jmusser]

As I've mentioned a couple times on here, I was lucky enough to come across the Nicholas Boscorelli Stompbox Cookbook the other day. It has a immense amount of information and effects circuits in it. The curious thing is, I have never heard of any of these circuits being mentioned before, or their schematics posted on the normal schematic sites. What's the reason? There looks to be some awesome circuits in his collection of "O-Matic" effects. Is it because a lot of it is digital, and therefore sounds "digital", or, because most of these are pretty advanced? Copyright stuff maybe? I have read, that a lot of people don't use digital effects, because they don't sound "organic", but since I'm ignorant of what that term means, I just go with what sounds good to me. A good example, would be the Jordon Boss Tone, and the Digital Octaver Fuzz. I built these circuits back to back, and I know you heard me rave about the Bosstone. This circuit I guess would be considered a standard organic analog pedal. Then, I built the Digital Octaver Fuzz. I really didn't know what to expect, and figured it would sound like something off a video game. It ended up having just as much, if not more character and grind than the JBT. Of course, they are two totally different tones, but what a monster it turned out to be! I'm just curious about these two issues.

[Paul Perry (Frostwave)]

I have the Boscoreli book, and I can't see anything digital in there.
One problem, is that most of the fx here use a LOT of parts, this isn't altogether a bad thing, they are designed so that component variation doesn't affect the fx, which saves a lot of trouble.
So far as copyright is concerned, even if the author is dead (I hope not, but surely someone would have heard of him by now?) the copyright of the layout and PCB drawings remain with his heirs.
Anyone can redraw the circuits if they want, though.
Interestign though the book is, there isn't anythign there that can't be done by stuff already available elsewhere.

[R.G.]

I was lucky enough to come across the Nicholas Boscorelli Stompbox Cookbook the other day. It has a immense amount of information and effects circuits in it. The curious thing is, I have never heard of any of these circuits being mentioned before, or their schematics posted on the normal schematic sites. What's the reason? ... Is it because a lot of it is digital, and therefore sounds "digital", or, because most of these are pretty advanced? Copyright stuff maybe?

Two reasons:
(1) It is primarily because of copyright reasons. The book is copyrighted. Reproduction of the material as exact copies by scanning is almost a textbook example of copyright infringement.
(2) The circuits themselves are quite complicated, as you note. They are not digital, but are instead examples of what I called "nail-it-down" design. They do not take advantages of some quirk of a component to do some function, but synthesize the function from opamps and other parts. The heritage of the circuits is obviously the synthesizer trade, as they use a clearly functional-block approach, violate the 9V battery rule in favor of +/-15V supplies,  and aren't really well set up in general to fit in a stompbox "wrapper" (See "wrappers" at GEO).

I don't think the stuff would sound "digital".

[jmusser]

I guess I've assumed (wrongly of course) that digital had to do with anything other than transistors or op amps. I figured if it got into exclusive ors, nands, nors, etc, it was considered digital. I'm guessing now that it has to be processor oriented tones. Chips are just consolidations of logic circuits as far as I know, so it looks like now, I've always been confused as to what "digital" was :?  :oops: So, are you saying that most of the stuff is way over engineered for what it has to do?

[school]

DIGITal, digital is information stored as digits, characters, what have you.  not so with analog where it is simply a current.

[Paul Perry (Frostwave)]

I wouldn't say they were over engineered for what they are, that is, completely replicable fx.
One of the advantages of DIY is that you don't have to worry about using a few more parts.. if you are making a hundred, then you have to think twice. An AD633 multiplier at say $6 hurts, but buying a hundred of them REALLY hurts :x
The good thing with Boscorelli designs is that they sound the same each time you build them; the bad thing is that yours can't sound better than anyone elses! (unless you tweak... but in general his stuff isn't as tweakable as say a FuzzFace or early wah, where changing one resistor can make several aspects of the circuit change at the same time.)

[Mark Hammer]

A word or two about this type of "digital" effect...

CMOS chips are generally used for processing logic level signals of a high/low nature.  Some CMOS chips CAN, however, coexist nicely with analog signals and other analog circuitry.  The CD4013 which exists in 90% of all octave-down boxes is a perfect case in point.  It is a chip intended to address  *information*, but is used to address *signal*.

If a DIY design uses a CMOS chip to accomplish a task normally addressed by something else, you will sometimes see it described or referred to as a "digital" whatever.  A bit misleading, if you ask me, but that's the basis for the usage.