[krazygluon]

I was just curious if anyone uses / has used this technique for prototyping. I built something with it once and was pretty impressed with it. I know connections have to be soldered, but the wire wrapping seems like a good way to pre-connect the board prior to testing.

 

[labrat]

Deleted.

 

[Excalibur]

It's great as long as you don't try to build any high-speed circuits with it. Wire-wrap can be kind of noisy.

 

[rickcr42]

Wire wrapping produces a gas tight and very solid connection that should last as long as any human here will but obviously suited to the "one of" or prototype only.For large scale boards was THE method before LSI chips came into play and i have seen early computers using this method exclusively.
The wire itself actually the same stuff many purchase on ebay (or other sources) as Audio Grade Wire and has the silver over copper that some find appealing but this is no easy tecnique and does require a specialised parts (the posts) and wrapping tool.

 

[krazygluon]

I remember from the box (not audio, something physics related) I built using it, that it was a tricky technique to learn, I was mostly concerned with how the wires affected sound, which from what it seems by the replies, isn't a terrible problem. Of course a previous comment just reminded me of why I don't own a wire-wrap tool of my own: the electric ones are like $200+

 

[rickcr42]

Any prototyping method suitable for a high density digital board that does not have clocking erorrs (all RF remember) should be OK to use for high speed audio though way overkill for a method always intended from the start for the large board/large scale/high density computer plug in board.
If that means it will sound OK I can not say never doing this at audio but "back in the day" I would get all my wire wrapping supplies from either OK Industries or Jameco,both who are still around so maybe do a search to check the options

 

[SiBurning]

Firstly... You shouldn't have to solder the wire wrap itself. You only need to solder the components to the terminals.

I like wire wrap terminals for building point to point. The terminals make nice solder points, and you have the options to solder components and leads on both sides. You can even wire wrap the things if you want. The interesting terminals are bifurcated, trifurcated, and the socket pins for prototyping/component swapping, aside from the plain ones.

The terminals are fairly stable, if not great, and component leads can be twisted onto the pins to make a stable physical connection. For more stability, components can be glued or tacked to the perf or copper clad board. Small parts can be mounted flush with the board, and other components mounted above them, floating in air. This kind of standoff construction can also be useful when modding an existing circuit.

Just thinking in terms of how to construct and mod things... Printed circuit boards are a pain to make, especially for apartment dwellers--very messy and you have toxic chemicals to house and dispose of. I'm just starting to experiment with Manhattan style. I'm thinking in terms of combining Manhattan, regular wire wrap, wire wrap terminals for point to point, surfboard, and Wainright (http://www.rdi-wainwright.com/). I'm thinking eventually to get a set of custom wainright boards made up at a pcb house, particularly ones that can be mounted perpendicular to the main board.

What other options are there aside from custom printed boards?

 

[recephasan]

I recommend getting the modified tool from Rat Shack. It is a quarter of the price of the one from Jameco.
The unmodified tools don't wrap any insulator, and therefore leave a part of the wire exposed, a recipe for shorts.

Never wirewrap and solder the same joint.

Now, about audio quality. I do not suppose there were many tests done, but audio is different than early computers, where the quality of the signal mattered less and the frequencies were in the low MHz range. With audio, all kinds of crap **may** bounce back and forth and/or can be picked up by the long wires and socket leads.

I made several wirewrap amps (cmoy, ppa, ...) They are bulkier, that's for sure.

Any other inputs on sound quality?

 

[rickcr42]

W Quote:

ith audio, all kinds of crap **may** bounce back and forth and/or can be picked up by the long wires and socket leads.

Explain

 

[Excalibur]

You cannot place opamp power rail decoupling caps, MOSFET gate resistors, and other "distance sensitive" components using wire-wrap. There will be additional noise and/or oscillation if you do.

 

[rickcr42]

Sure you can ! right at the wire wrap IC socket pins !

those babies (and i have one in fron of me as I type) are like a full inch long so no reason you can not attach parts right at the socket which MUST be used with ICs and wire wrap construction.

Quote:

Never wirewrap and solder the same joint.

I resemble that remark !

Folks need to realise the wire wrap post is a square and not round post so the connection is a very secure gas tight connection.It will not work its way loose so solder only offers the risk of solder bridges but zero benefits

 

[MN Ham Phones]

Quote:

Originally Posted by rickcr42 Folks need to realise the wire wrap post is a square and not round post so the connection is a very secure gas tight connection.It will notr work its way loose so solder only offers the risk of solder bridges but zero benefits

Indeed, even NASA used it in the Apollo Spacecraft.
And I used it in a Rocket boosted camera.

 

[SiBurning]

Quote:

Originally Posted by rickcr42 Folks need to realise the wire wrap post is a square and not round post so the connection is a very secure gas tight connection.It will not work its way loose so solder only offers the risk of solder bridges but zero benefits

To add to the last post, the biggest problem with wire wrap is breaking that fragile 30ga wire. I suppose this problem is lessened with the modified wrap, but I used to break a lot of unmodified wrap wires by just moving existing wires to move them out of the way while trying to add new wires. Inevitably, by the time the board was wired, a few would break right where the wrap stops.

 

[rickcr42]

Quote:

To add to the last post, the biggest problem with wire wrap is breaking that fragile 30ga wire. I suppose this problem is lessened with the modified wrap, but I used to break a lot of unmodified wrap wires by just moving existing wires to move them out of the way while trying to add new wires.

Something we must deal with when it comes to solid wire in general.I use solid wiring in all audio electronics wiring unless for long runs where it will be flexed or like with some of the Beldon cables has a good amount of flx-protection as with the foamed core and rubber jacket which prevents the focused stress point you get with solid-wire-to-solid-surface contact point.

wire wrap compounds that with the sheer amount of force the wrapping tool is able to bring to bear on a small footprint area (the wire/post joint) so the very thing that makes this such a good connection,the gas tight nature,is also what makes it a potential break point if there is large scale movement such as from physically moving one wire to insert another nearby.
vibration however seems to have no similiar effects and even shipping a wire wrapped board it is rare to see one fail from broken contacts no matter how hard the USPS/UPS/FEDEX boys try

The fix is to simply do a good permanant layout from the start or if modifications are foreseen leave a kluge area so the actual circuit is not disturbed when adding in the updates.