Best Jamma Adapter?

_jmfr

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What do you guys think? The only new ones i've tried were from Jammaboards. The quality is ok, just wonderin what my other options are. Also, what kind of wire ties do yall use?

Thanks,
Jason
 
JAMMABoards only sells mass-produced chinese copycat crap, for the most popular boards / pinouts, and has artificially deflated prices on adapters to the point where it's no longer profitable to fab new designs, ensuring that the 4-5 adapters they sell are about the only ones out there.

It's certainly not worth my time and trouble to design and fab boards for adapters that people will expect to sell for $15 ($4-5 of which is the edge connector), when I'd be lucky to sell 10 ever, so I'm out of the market.
 
Bob Roberts makes them. They are not pretty or cheap (he builds each one with a fingerboard, wires, and solder), but they get the job done, better than the mass-produced ones according to Bob (better current flow).

http://www.therealbobroberts.net/adaptors.html

Bob is full of shit. If there was any validity to his claims, then the adapter would heat up as you ran the board and you'd eventually burn out the traces. I've never seen a PCB-based adapter with burned out traces. Iif there's a short on the board, there's usually a trace on the board that'll burn out long before the ones on the adapters.) If you're really *that* concerned about the power traces on a PCB-based adapters, you can always add more wires.

Here's one of bob's adapters:
kon.jpg

If having enough wires for power is so essential, you might want to ask him why he shares wires for adjacent power pads instead of running separate wires to each pad.

Simply stated, he thinks his way is best, because it's the only way he can make them.

I started out doing adapters that way (and still built them that way for one-offs), but it's really tedious and time-consuming, and potentially error-prone, so about 11-12 years ago I started fabbing boards since (pro-rated) they took less time to build, so I could sell for less...
 
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yea sorry but current flow is not an issue here at all.
otherwise you would not have a pcb board that is made it would all have to be wires then. lol

now bob makes some things you cannot get anywhere else then get it.
but the long term failure rate on wires with solder is much higher than a made pcb board adapter.
 
Bob is full of shit.

Thicker gauge wires have a lower impedance than thinner gauge wires (or lighter traces), all else being equal, therefore, you can adjust the gauge for whatever current flow you need. Additionally, the distance that the electricity has to travel on the traces alone (before and after it travels on the wires) is shorter than if the adapter was made from traces alone. A shorter distance for electricity to travel = lower impedance as well; all else being equal.

On which of Bob's points do you specifically disagree with?
 
yea sorry but current flow is not an issue here at all.

It can be on the power and ground lines. Not all traces are created equal.

but the long term failure rate on wires with solder is much higher than a made pcb board adapter.

That's speculation, unless you have some long-term test results to present.
 
I don't know why people bitch about the "quality" of the Chinese knockoffs or wire-jumpered adapters, etc. If it works, then that's all that matters. Sure, it would be nice if we could make and sell adapters for profit, and the mass-produced ones make it less cost effiecnt to do so, but that's the kind of thing that happens when we need small runs and a living wage. If we were paying the workers 15 cents a day to build these things, we could sell them cheaper, too.

If you're blowing traces, then you most likely have other problems than the adapter quality. I've only had one adapter burn a trace, and that was due to a short on the board, not the adapter...
 
I think the best way is to do the shit yourself.

That way, you can do it right.

And you can't blame anybody else for fuck ups.
 
Bob is full of shit. If there was any validity to his claims, then the adapter would heat up as you ran the board and you'd eventually burn out the traces. I've never seen a PCB-based adapter with burned out traces. Iif there's a short on the board, there's usually a trace on the board that'll burn out long before the ones on the adapters.)

You can have restricted current flow that's enough to cause game issues, but not enough to actually burn out a trace.

As an example, my Ikari Warriors came with one of those PCB adaptors from the factory; it is something Dynamo did because they had their own wiring scheme (similar to JAMMA) and they adapted it to the SNK pinout with a PCB adaptor. I don't care for kludges like that, so I got rid of it and cut off the 56-pin Dynamo pinout Molex card edge connector and replaced it with a 44-pin Molex card edge connector wired directly for the SNK pinout.

After doing that I measured the +5V at the board and it was .2V higher than with the old setup, so I backed it off on the power supply's +5V pot until it measured at its previous level. If nothing else, the power supply gets a slightly easier life out of the improved current flow.

If you're really *that* concerned about the power traces on a PCB-based adapters, you can always add more wires.

That's certainly true.
 
i agree with you mod.
but my only concern with the chinese ones would be at the edge connector
those pins may only be rated at 30-40 times to be takes on/off

but you have to just laught at the "current flow" of wires vs pcb adapters.


To maxrecoil:
and solder joint is a point of weakness/failure in comparions to a trace with no breaks.
for example: take coaxial cable
10 foot long single piece vs Five 2 foot long pieces with appropriate connectors

you will have 4 points of possible failure (one at each connector) as you will with solder

and as for any long term data, no i have conduced a research study yet. lol

but we have a whole hell of alot of repairs on cold solder joints and bad pins poor soldering jobs ect ect. (alll having to do with points of poss failure)
 
but you have to just laught at the "current flow" of wires vs pcb adapters.

What's laughable about better current flow?

To maxrecoil:
and solder joint is a point of weakness/failure in comparions to a trace with no breaks.
for example: take coaxial cable
10 foot long single piece vs Five 2 foot long pieces with appropriate connectors

you will have 4 points of possible failure (one at each connector) as you will with solder

and as for any long term data, no i have conduced a research study yet. lol

but we have a whole hell of alot of repairs on cold solder joints and bad pins poor soldering jobs ect ect. (alll having to do with points of poss failure)

On the other hand, solder joints can last longer than a person can be expected to live. Your claim stated positively that "the long term failure rate on wires with solder is much higher than a made pcb board adapter". A simple count of potential failure points can not be extrapolated into such an authoritative statement.
 
Thicker gauge wires have a lower impedance than thinner gauge wires (or lighter traces), all else being equal, therefore, you can adjust the gauge for whatever current flow you need. Additionally, the distance that the electricity has to travel on the traces alone (before and after it travels on the wires) is shorter than if the adapter was made from traces alone. A shorter distance for electricity to travel = lower impedance as well; all else being equal.

On which of Bob's points do you specifically disagree with?

Points? His points don't even speak to the things that *actually* matter.

The fact that the contact resistance of the connectors involved FAR swamps any difference in impedance of the wiring on either kind of adapter.

The fact that his adapters have 3 solder joints per wire vs. 2 solder joints in an PCB-based adapter, or one that's wired point-to-point from edge connector to a single-sided fingerboard. (And the solder joints have a much higher impedance than wires or traces).
 
i agree with you that it "can" last longer than i can live
but it also "cannot" last longer than i live.

and what is going to happen to a pcb adapter, unless you step on it or drop it.
 
After doing that I measured the +5V at the board and it was .2V higher than with the old setup, so I backed it off on the power supply's +5V pot until it measured at its previous level. If nothing else, the power supply gets a slightly easier life out of the improved current flow.

If your adapter was dropping .2V, then it was dirty and needed to be cleaned.

Your board takes approximately the same amount of current regardless of what voltage you give it... putting out 5V instead of 5.2V isn't going to make any difference in the lifetime of your power supply.
 
The fact that the contact resistance of the connectors involved FAR swamps any difference in impedance of the wiring on either kind of adapter.

That doesn't render the impedance of the wiring irrelevant.

The fact that his adapters have 3 solder joints per wire vs. 2 solder joints in an PCB-based adapter, or one that's wired point-to-point from edge connector to a single-sided fingerboard. (And the solder joints have a much higher impedance than wires or traces).

Solder joints have a higher impedance than wiring or traces, to varying degrees depending on the solder alloy and mass and length of the fillet, and the material the wires and traces are made of and their mass and length...

But regardless of all of that; is it your claim that it is impossible for one to make a fingerboard/wire type adaptor with better current flow than a JAMMAboards PCB-type adaptor?
 
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