GM5: Least-cost USB-MIDI Interface Chip for 4.50 EUR

[technobreath]

Dudes, I kinda like this idea. I'm not quite sure though that it will easy enough for community to jugde, as there aint so many alternatives for design... you know what I mean? Or am I not seeing something? If it was to be fair, it should be judged by the community, and not single person like me anyway. I guess it should be decided with a poll or something, say, between the top ten or top 5 or something?

[rosch]

ok i'll deliver the rest of the board components then for the winner (not the panel mount stuff).

how about opening a thread in the misc forum and a mod could move the posts there?

i just looked we won't get 2 boards next to each other in 19" and on top of each other won't work either.

so it would have to be all panel mounted. preferably easy to access midi jacks (Reichelt maybe)

are there panel mount usb jacks?

another way would be one on the front and one on the back, but wouldn't look so clean.

about judging, there could be a poll and every member could vote if they like.

[V`cent]

-Snip-

i just looked we won't get 2 boards next to each other in 19" and on top of each other won't work either.

so it would have to be all panel mounted. preferably easy to access midi jacks (Reichelt maybe)

are there panel mount usb jacks?

another way would be one on the front and one on the back, but wouldn't look so clean.

about judging, there could be a poll and every member could vote if they like.

How about one "the usual/right way(pcb bottom is touching the bottom of the case)" and one flipped 180 degrees (bottom of pcb is on top of the case) ?

Panelmount usb exists, but look shite :

http://www.ebay.co.uk/itm/USB-A-male-to-USB-A-female-panel-mount-adapter-cable-/220829329614?pt=UK_Computing_CablesConnectors_RL&hash=item336a7428ce &

http://www.ebay.co.uk/itm/1-Feet-Panel-Mount-USB-Cable-B-to-B-F-M-/200778962666?pt=UK_Computing_USB_Cables&hash=item2ebf5bd6ea

.... Some sort of creative compromise would probably have to be reached, or a seperate thomann order for one of these : http://www.thomann.de/dk/neutrik_nausbb.htm or http://www.thomann.de/dk/neutrik_nausb.htm ?

[ilmenator]

How about one "the usual/right way(pcb bottom is touching the bottom of the case)" and one flipped 180 degrees (bottom of pcb is on top of the case) ?

So that half of the connectors are sitting upside down? Bad idea from a usability point of view.

[technobreath]

OK.

Seems that it's kinda settled that the compo is to be about the 19" case. Cool.

To conclude then:

I'll set up the thread, but there's gonna have to be some guidelines for the design then, and my proposition is the following:

1. One MIDI in / out on the front

2. 8 MIDI I/O on the back

3. USB on the back

4. Option on back for external powering (something like this: mouser.com part number 502-S761KS12) I use these and they are VERY sturdy!)

5. USB Hub inside (does this work?) Meaning only one USB connector on the back

6. LEDs on front for MIDI I/O

7. PowerLED on front (neccesary?)

8. MIDI plugs should be panel mounted so that we don't have to design and produce another breakout pcb to put the connectors on.

I will use the winning design myself for my own interfaces :). Obviously I won't be competing myself.

Also, the USB connectors in the post above looks nice, but it should really come from a reliable and consitent source, which ebay tend not to be. I myself would be really comfortable with those nice Neutrik USB connectors (mounts in same space as a XLR panel mount.

If there's any comments, please add em.

[ilmenator]

If there's any comments, please add em.

Sounds a LOT like Emagic's AMT-8 :whistle: .

[nILS]

Alright, I'll talk to TK how we'll handle the order(s) and then report back :-)

[V`cent]

So that half of the connectors are sitting upside down? Bad idea from a usability point of view.

No, he said panelmount connectors, so the connections on the inside would be different, but you would just align the second set of connectors to the first one (they would be wired up anyway) ?

Even if you use pcb/boardmount connectors, would it be so bad to have ~4x in/out on the back that are upside down?

[ilmenator]

No, he said panelmount connectors, so the connections...

No, he said panelmount when he was referring to the USB connectors. And yes, it would really be so bad, because you never knew for sure which way around to plug the connector unless you tried. Especially annoying when making new connections in a rack, when the backplane of the device is most probably sitting considerably deeper buried into the rack than that of all other gear.

[rosch]

exactly. and on top of that you'd have the order of the channels both going from outside to the center.

[V`cent]

so it would have to be all panel mounted.

...Hmmm

Anyhow, not trying to start a "who's right thread", it doesn't really matter, you could just panel mount them instead of using pcb mounts ^^

Edited September 14, 2012 by V`cent

[ilmenator]

He, you are right! I looked in the wrong quote... sorry!

Panel mount is of course possible, but then again I do not see the point in reversing one of the PCBs?

[V`cent]

He, you are right! I looked in the wrong quote... sorry!

Panel mount is of course possible, but then again I do not see the point in reversing one of the PCBs?

The idea was that they can then be "stacked"/overlap slightly, so that two pcb's could fit in a 1U rack :)

[sineSurfer]

Hi there and... arrrrgh!, I missed the chip bulk order for a couple of days, is there anybody buying more chips than needed who could let me buy one?

Thanks!

[shimoda]

Hi there and... arrrrgh!, I missed the chip bulk order for a couple of days, is there anybody buying more chips than needed who could let me buy one?

Thanks!

I ordered a few more chips (and pcbs) than I'll need just in case so I should be able to help you out.

[rosch]

then how about you change your count on the list and add sinesurfer too, that way you don't need to ship twice. as long as the total amount on the list doesn't change there should be no problem

[sineSurfer]

Hi shimoda, thanks a lot!, yes it could work as rosh suggests to skip shipping twice.

As I already have a spare mini pcb, I'm ok with 1 chip if you don't mind.

Laters!

[shimoda]

done, and I just added your name and single chip request sineSurfer. good idea rosch

Edited September 19, 2012 by shimoda

[sineSurfer]

sweet!, thanks a lot shimoda!

[nebula]

USB Hub inside (does this work?) Meaning only one USB connector on the back

If there's any comments, please add em.

If USB hubs add latency I would much rather have two USB connectors on the back.

[technobreath]

yes. opposite mounting doesn't seem like a very good idea.

EDIT:

Yes, IF they add latency that degrades performance - that is not wanted :). Someone who has two interfaces that would like to do a stress test on em with a hub? Or is there any tech specs that can tell wether this is an issue?

Edited September 20, 2012 by technobreath

[V`cent]

Sorry for my terrible paint skills, but meh.. This was my idea :

[rosch]

that's how i understood it. it would be the easiest way to get both in a 1U unit.

the only drawback is just that half of the jacks (incl usb) are turned around, and the numeric order is reversed too, as well as in and outputs.

but no need to drill holes for panel mount parts etc.

that drawback is actually not that bad if you're not gonna plug things on the backside every day.

[V`cent]

that's how i understood it. it would be the easiest way to get both in a 1U unit.

the only drawback is just that half of the jacks (incl usb) are turned around, and the numeric order is reversed too, as well as in and outputs.

but no need to drill holes for panel mount parts etc.

that drawback is actually not that bad if you're not gonna plug things on the backside every day.

Yeah, you could just use panel mount midi connectors though (if you are going to have a front plate done anyway) :)

Since my plan is to try to squeegee two 5x5x5's into one 1U rack, I'm probably going to buy one or two cheap 19' rack front blinds & some form of empty 1U rack case/drawer/something, drill some holes in the back (not going to be looking at it anyway) & wire 9 of the pairs to the back with panel mounts, and one pair to the front(+usb+status led).. Might even get a decent front panel made at some point.

+1 for the latency stress tests using USB hubs.. Would be interesting to add a USB 3.0 super speed hub to the mix, to see if it performs any better.. Sadly those things are far too expensive at the moment :(

[technobreath]

I don't think it's neccesary to use a super duper speed 3.0 hub.. u only need a hub that can handle the traffic of two GM5x5x5s. But time will show... all I'm saying, not neccesary to shoot bird with canon :P.

About the mirrored pcb idea. I agree, the practical downsides isn't really an issue if it's somewhat stationary module. But I'm not sure I like the idea aestethic-wise. But looking at it objectively it wouldn't be a very large problem if u only care about the practical stuff.

EDIT.

Now, I'm not gonna go all bossy here hehe, this is just a suggestion - would it be wiser to discuss the design stuff in the design contest thread, it is a bit confusing to have two threads about the same thing :P (hahaha like that's an unusual thing hehe) ?

Edited September 22, 2012 by technobreath