Anybody try "Manhattan Style" construction?

[martin manning]

The low-power (QRP) amateur radio guys have been doing this for ~15 years. The original idea is you attach small punched-out or rectangular bits of copper-clad PCB material to a copper-clad sheet with CA, but there is also a variation where islands are created by cutting a circular mote using a diamond core bit. The copper on the board forms a ground plane, to which component leads can be soldered at any convenient point.

In the picture below (which is in fact a push-pull audio amp) the cladding has been cut away to create the islands. Leaded components are used, but since the copper is all on one plane SMT parts can be used too.

No doubt a pedal circuit could be done this way, but I think tube circuits could be prototyped if the socket were mounted on stand-offs.

[eniam rognab]

have you been reading the ARRL handbook? cuz i have and i believe they use the same picture only in B/W. i've never seen a circuit built this way but it is interesting...

[jazbo8]

Are you proposing using the ground plane in place of the star ground or in addition to it?

[martin manning]

For tube circuit prototyping I was thinking this might be good a good way to put together a couple of preamp stages or perhaps a vibrato circuit for testing with a remote power supply, so no real need for a fancy ground scheme. For something with small and lightweight parts like a pedal, this would probably be fine for a finished build. I could see doing some through-hole mounting for heavier parts.

[matt h]

(deleted)

[jazbo8]

For prototyping, I would think it is perfectly fine. If all the "modules" are then joined together with a star ground scheme, they should be fine too. But I would not build the actual amp that way.

[Andy Le Blanc]

the minimal distances are desirable, the only drawback might be heavier components pulling off the pcb from G shocks, "hook up" is the solid mechanical connection before solder.

[xtian]

This really allows the anal---uh, artistic side of circuit design to show thru. Very cool.

[JMFahey]

I have often built amps and preamps that way,always on single sided copper clad board, with copper "up" of course.

Allows for fast prototyping, easy modding, a big advantage is that the bottom is insulated so you can reasonably put it on anything.

I have glued such boards inside actual metallic chassis, wired them to pots, jacks and switches, and have even tested them onstage, with live bands.

But instead of cutting and peeling copper, I have covered boards with dot patterns similar to "5 points" on dice plus long end to end ground and rail strips, all painted with water resistant sharpie pens, and then etched in ferric perchloride, the standard PCB etching bath.

Too sleepy now but will take and post some picture tomorrow, if you need it.

EDIT: you can also make such boards with same pattern eyelets on an insulating board, think "general purpose old style Fender eyelet boards" .

Saves on etching and stands endless modding.

[martin manning]

Thanks, John. What appealed to me was the lack of any etching, and the flexibility to quickly glue pads down anywhere as you build without resorting to some sort of predefined grid that will have a lot of unused pads. Pre-tinned pads http://www.qrpme.com/?p=product&id=MES and pads for DIP's http://www.qrpme.com/?p=product&id=MEP are available for use with this construction technique, which looks like a great system. A nice example is here (scroll down), using a bolted aluminum chassis from Seaside: https://aa7ee.wordpress.com/2014/08/21/ ... -in-coils/

I have seen references to CA-glued pads coming loose with repeated soldering, and some concern about breathing fumes from heated CA. The machined pad version is nicer and avoids all that, but it means planning the layout in some detail beforehand.

It's worth looking around a bit to see how others are doing electronics DIY...

[Structo]

I think I might have a problem with the super glue.
Seems to me that it wouldn't be good used on anything that heats up much.

On the other hand, a machined layout would work great and nice fat traces could be used.

John Suhr (Suhr Guitars and Amps) uses a CNC machine to make prototype circuit boards and for other projects.

[martin manning]

CNC is commonly used for prototyping PCB's, and it avoids the need for the etching process and all the PITA environmental issues with the chemicals. Obviously it's not something everyone has access to, though.

That's where the diamond core bit method of creating pads for this style of construction comes in- you can ditch the CA and still spot the pads anywhere you want using a $15 cutter and a small drill press (like a Dremel unit). That's only good for round island pads, but I could see an approach where a tiny template could be used with a Dremel tool to do routes for DIP IC's and other specific components.

[ampdoc1]

I think you're about 25 years behind. Check out the EXEF preamp with interchangeable preamp modules. A solid state preamp for the clean circuit, and 2 input internal circuit boards for the various (8-10) tube overdrive plugin modules. Also it included unpopulated plugins for designing your own circuit.

[martin manning]

A modular tube board is not really what interests me, more that it's a quick, cheap, no-etch, and very flexible way to build up any kind of circuit.

Merlin Blencowe is offering some modular PCB's for 9-pin tube projects, BTW: http://www.valvewizard.co.uk/developmentboard.html Someone here was trying to use them for a whole amp build, but I don't know how far it went.

[beasleybodyshop]

Martin, this is a very cool idea! Ive never heard of this type of building.