SumThing Passive Summing PCB - Schematic and Layout

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[quote author="rbaker"]any updates on this?[/quote]

Yes. Sorry I haven't posted - Just waiting to have a first set of boards in hand. The gerbers are ready and we should hopefully have our first prototypes this coming week or next.

The PCB was redesigned for ITT F-series switches which are a bit larger and have a longer switching throw than the PHA series. They are also available in gold contacts for audio applications if the builder wants to pay the extra cost.

I am going to build one or two to test, then we may have some extra boards available from the first run to anyone who wants them. After I've got a finished unit to show, we'll gauge interest and run more boards if people want to give the project a try...

More info soon...

Josh
 
the pushbuttons are really the best part about this..... i'm really glad the input 1/2 bypass to output 1/2 made it, as that seemed to me to be the one easy place to save two patch cables.

anyway, I'm really glad the switches aren't outrageously expensive..... but they do have those cool mechanical indication caps available ;]

Very nice guys, hope my input in the other thread helped a little as novice as I am.

Anyway, I'd love to get one or two. Just wish I had 16 outputs now ;]

Thanks for the board, and thanks Dave for the design

Billy
 
oh yeah, forgot to ask....

Are the headers for DB25 to be used with an idc header and an idc ribbon cable to DB25, or are there DB25's that fit that spacing?

If the DB25's do mount right on board, is the pcb sized so that it works with a certain enclosure if using pc mount switches and db25 connectors?

Billy
 
[quote author="enthalpystudios"]anyway, I'm really glad the switches aren't outrageously expensive..... but they do have those cool mechanical indication caps available[/quote]

Yes, the switches are pretty reasonably priced. I found the lowest price from Newark, versus digikey or mouser. I did not find any place that stocks the mechanical indicator caps, although I did see them in the datasheet. Haven't looked very hard tho - let me know if you find a place that caries them. Also, one will need to watch the horizontal width of the indicator caps - I think they are a bit wider. The PCB spacing is such that the standard large size rectangular caps fit mounted horizontal (or vertical), with a small amount of space between each set of 4 for panel support. I will post an updated PCB layout and some dimensions soon.

[quote author="enthalpystudios"]
Are the headers for DB25 to be used with an idc header and an idc ribbon cable to DB25, or are there DB25's that fit that spacing?[/quote]

The layout is for a IDC header. In addition, the pinout is such that a PC-motherboard style IDC->DB25 cable will produce a tascam/protools format pinout on the DB25. These IDC->DB25 cables are available for about $1 each from various sources. I ordered 10 from pccables.com (they take paypal payment, a plus for a first time order) and they arrived a-ok. I'll include them w/ the boards for the first few orders, and if the interest is there, I can order from them again. Since the cables are premade this should make everyone happy who didn't want to solder db25 cables :grin:

And absolutely thanks for all the input and enthusiasm :thumb:
 
Sorry I've been slackin folks - in the last month I went through a change of jobs and things have been hectic for me, so less time for diy. Getting settled into something new next week, so hopefully more time coming up.

We got the boards back last week, but I haven't had time to get photos made to post. coming soon. We're building up the first board friday... I'll post pics of that too.

I may have one or two extra boards from the first run, so if you're interested drop me a PM or email. Because they were low volume prototypes they're a bit more $$$, but its not too bad. If the interest is still strong enough we'll do another run to get the cost lower... and I'll move this to the black market at that point.

jt
 
[quote author="solder_city"]i dont understan you people at all... you could have hanwired like twenty of these during the time youve been waiting for these pcbs. lol! :green:[/quote]

Each to their own I suppose. Why do some people BUY passive summing boxes? Now if you're point is that I/we have been very slow on this project - I can't argue there, its not a major rush for me and so things have moved along a leisurely pace. I'm sure some people probably did go ahead and wire their own. Its all good :grin:

Now, after much admitted delay, here are the pics of the PCB, stuffed board, and DB25 connector used:

Bare PCB
Populated PCB Example
PC Style DB25 example

Remeber that you can populate in various ways:

- with or without switches
- with grounds lifted, cap bypass on ground, or a jumper to lift ground (Cx)
- With .1" headers for I/O connections
or
- with .2" screw terminals for I/O connections
and/or
- IDC26-DB25 cables for tascam format db25 output (see photo for cable used)

The prototypes of this run are already claimed and are being used for further testing. We are also altering the design slightly because we liked the idea of a bypass, but not how its implemented here (it can just be left out of these boards). The new bypass will optionally allow the use of a seperate MIC PRE IN/OUT set of connections. When bypass is engaged, the mic pre will be taken out of the path of the main output. Any feedback on that idea is welcome.

I do know this project has been slow going, but we both have full time jobs and families, so thats just how it goes... Thanks for those who've stuck in there, and who are testing boards! :thumb:

Drop me a PM if you want more info on getting boards sooner than later (I may be able to get you prototypes). Otherwise I will create an order thread in the black market once we've got the next version tested. I hope to also provide the DB25 cables w/ the board to those who need it.

Thanks again,
jt
 
[quote author="thebearingedge"]I'm sorry, so how do you adjust panning and level again? I may be thinking of another thread. :oops:[/quote]

don't be sorry, but I guess you might be thinking of another thread. There is no panning and level control on this design - the idea was to stick w/ a fully automation driven passive summer w/o level/pan. There was some discussion by others that were interested in these controls, but ultimately we wanted to keep the unit simple and went w/ this design...

jt
 
[quote author="Bauman"]Hey I like this :) Any idea on pricing ??

cheers!
Fabio[/quote]

I don't want to say anything too definitive yet - it really depends on the level of interest and as such, the quantity of orders. We should be able to get them down to $15-20 range short term or under $15 if we have enough interest. Of course as prototypes we are paying about $35 each (w/ shipping) in very small quantities... I think we should have a finished version next pass though, so we'll move on to collecting a sense of pre-order interest and get some pricing to everyone.

I can get some specific quotes and drop you a PM - The fellow who designed the board layout (he's only a lurker from time to time here) is handling all the orders - I check with him on the numbers...

Very pleased that you like it btw :grin: thanks!
 
I just ordered 2 boards and had a couple of questions be for I order the components to stuff them.
1. What are the optional 0.1uF bypass caps for. Why would I want or not want to use them?
2. Has anybody build one with the gold switches?
3. If gold switches are used would there be any noticable sound difference over the standard ones?

Oh yeah couple more questions. . . . what watt R do I use. . . is a 1/4 watt resistor OK? And what type? Should I use metal film?
TIA
Joe Fanelli
 
FWIW I have decided to down size my studio and no longer will be persuing mixing OTB. I had purchased 2 Sumthing board and never did anything with them. Therefore I am going to let them go. BTW I have the DB25->IDC26 ribbon cables for each as well.

1 board - $35
2 boards - $60

$ Includes USPS flate rate shipping

If interested please email me at soundtrack2life at aol dot com.
Thanks
Joe
 
I just bought a sumthing pcb off someone here on the forums.  I ordered the PHA2UEE switches from digikey(part #401-1192-ND) as stated on the first page.  They definitely don't fit the pcb.  I should have checked the measurements, but didn't think it was necessary since jtoole said they fit.  Anyone know what switches work with the sumthing?  I hope there is because I just spent $40 on switches!
 
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