Jack continues his clever ways ! ( new at AMZ...)

[Dragonfly]

Now fellas, THIS is cool ! Some smart thinking if you ask me... being able to easily build Mosfet Boosts, Jfet boosts, LPB boosts, buffers, Rangemasters, etc, etc all on the same PC board !

Jack... I hope you don't mind me posting this....

[newfish]

That's brilliant!

Congrats to Jack and his immense brains!

[R.G.]

Selective population is an old trick.

Back when I was running the Geofex store and selling parts and PCBs, I cooked up several selective-population PCBs; one I called the Omni-face. It was a single board that let you populate it to be any one of the fuzz face variants, or any one of the FF-plus-buffer variants like the tone benders marks one through at least three as I remember.

I never got much response to it, nor to the selective-population boards in the FXBus setup, so I didn't carry it on much. Maybe I was just several years ahead of the audience.

I'll see if I can dig those out of the archives if it's of any interest.

[ayayay!]

Sure it's cool!  Actually what got my attention more than anything was the screw hole in the center of the board.  That makes a lot of sense for tiny boards.

The Ibanez soundtank PCBs are a lot like that too.  My TS5 is mostly unpopulated but it looks like you could build all kinds of stuff on it.  I had a Morely volume pedal that was like that on the inside as well. 

[analogmike]

I like that... very good for our custom projects and R & D, I will order 10 if it's ok to use them commercially, please let me know.

[joegagan]

yeah mike, it already looks quite similar to your existing boards. nice to see this kind of interaction here at  aron's.

[amz-fx]

Thanks for the plug, and the kind comments everyone!

Anyone that buys a pcb from me can do whatever they like with the board...  use it in a commercial pedal, sell it, whatever.

@analogmike: if you want 10 of them, send me an email and I'll give you a discount.

Thanks again.

regards, Jack

[iaresee]

Jack, is this usually the case for your boards? I just built your Ge buffer and really dig it. I've got pedal board clients asking about buffers -- I'd happily offer them your buffers, built by me, on your boards if that's cool with you.

[amz-fx]

Jack, is this usually the case for your boards? I just built your Ge buffer and really dig it. I've got pedal board clients asking about buffers -- I'd happily offer them your buffers, built by me, on your boards if that's cool with you.

Yes, if you buy any board from me it is yours to use or sell as you please.

regards, Jack

[amz-fx]

Actually what got my attention more than anything was the screw hole in the center of the board.  That makes a lot of sense for tiny boards.

The hole in the middle of my pc boards can be used for a screw mount but it is also sized to fit the 3/16" high standoff  Eagle Plastics/Mouser p/n 561-LAD187 which is also sold by Small Bear.

regards, Jack

[Jered]

Selective population is an old trick.

Back when I was running the Geofex store and selling parts and PCBs, I cooked up several selective-population PCBs; one I called the Omni-face. It was a single board that let you populate it to be any one of the fuzz face variants, or any one of the FF-plus-buffer variants like the tone benders marks one through at least three as I remember.

I never got much response to it, nor to the selective-population boards in the FXBus setup, so I didn't carry it on much. Maybe I was just several years ahead of the audience.

I'll see if I can dig those out of the archives if it's of any interest.

  RG, your FX bus was brilliant. I was surprised one of the commercial guys didn't copy it or want to buy it. Fun pedal building blocks.

[amz-fx]

Paia offers a rack mounting system that can be used for FX:



http://paia.com/fracrak.asp   Fractional Rack (FracRak) Packaging System: This card frame packaging system fits up to ten 5.25" x 1.5" x 7" modules into a standard 3U rack space.

Craig Anderton originally used a Vero rack system is his Electronic Projects for Musicians book, but it is quite expensive as I recall.

regards, Jack

[R.G.]

Thanks Jack - but the Frac Rack and other similar systems were made long before the FxBus.

The FracRack and Craig's Vero Rack system were mechanical modularizations. The important idea in the Fx Bus was the electronic modularization. You really have to have both to have a successful backplane system. The mechanical enables the electronic.

The study of electronic communication busses is a specialty all its own in EE. I had a bus wizard working for me at one time back when I lived in the belly of the beast. One day I bought us coffee and asked casually for a quick intro to bus theory and didn't get away for the next two hours!  I was very interested for about the first hour and a half.

The FxBus, and to a certain extent the "bus" internal to the Modular Phaser are a simplistic look at audio and analog busses, and much simpler than, for instance, the busses inside a big mixer.

The FxBus from 4/2000 contains another few nuggets of selective population. FxBus module 1 is a buffer/gain/booster module that I got tired of counting circuits that could be put on that board, much like the PCB mentioned in this thread. The chart lists a few of the personalizations. If I ever get time to get back to the FxBus, I'll nail down a mechanical modularization to go with the electronic modularization. It needs something about the size of a large stomp box, maybe the old Mutron Phaser, and a way to put flat bits of aluminum for front panels containing the controls.

On a larger scale, the mechanical modularization in the http://geofex.com/Article_Folders/FXRack/fxrack.pdf gives a way to construct something more friendly to the stompbox afficionado than either the FracRack or the Vero cases. It's heritage is from the earlier PAIA synthesizer style stuff, by way of the Steel Studs enclosure. Somebody with a hacksaw, file, and electric drill can turn out a "rack" enclosure that can be an entire pedalboard. One useful mod to that is to make two of the FX Rack enclosures and hinge them on one side so they close like a clamshell. Glue vinyl to the outside with contact cement and you have a pedalboard that is its own steel-shell carrying case.

For small boards like the single-transistor boosters, I prefer to put all the copper and electronic parts on one side of the board, no holes at all. It's "surface mount" for normal parts by bending the leads out and soldering on the surface. It works fine for smaller boards, and is illustrated here:

This was my first attempt. The wire connection pads really should be longer to add some more surface area for mechanical stability, and if you were doing belt-and-suspenders, you'd put a row of blank holes for the wires to come up through from the blank back side to fold over onto the solder pads, or a glue area to hold the wire sleeves in place. But it works for experimentation and other low stress uses. Normal DIP ICs work really, really well this way. A quick twist with needle nosed pliers and all the legs on an entire side are bent out flat for surface soldering. It's surface mount for the magnification-impaired! 

The blank back side lets you do something very handy - superglue, contact cement, or velcro the PCB to a jack or the back of a pot. In the case of the Rangemaster, the Rangemaster boards I was selling - what? six or eight years ago? - used this style of mounting for parts and the board. The nice thing about having the whole back side of the board clear is that the whole board can be glued to the back of the single potentiometer, eliminating any board mounting provisions at all. It's quite sturdy enough for small single boards.

For those people who are into a bit more advanced PCB layout, you can in fact, lay out the PCB so that there is a spot on the back of your PCB that is clear of any traces except ground perhaps, and still do a through-hole board normal style. Like it says in "PCB Layout for Musical Effects", you have to think in planes.