Discrete Summing Mixer, the "Stereotype" PCB's

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hakanai

Well-known member
Joined
Oct 18, 2009
Messages
193
Location
Brooklyn NY
7/21/14 Boards are in and shipping

6/16/14 Ok New boards have been ordered and I am now accepting orders. You can see the prototype here:
http://groupdiy.com/index.php?topic=41430.msg718634#msg718634

Boards should ship in 2-3 weeks.

~~~~~~~~~~~~~~

Basically it is a Summing mixer that uses API 2520 DOA's at the input and feed classicapi.com's summing board. That can be found here:

http://classicapi.com/catalog/product_info.php?cPath=22_46&products_id=403

opamp and PSU compatibility are addressed here:

http://www.groupdiy.com/index.php?topic=41430.msg619627#msg619627

There is only one board currently available, the 4 channel input board. The channel board is still in testing. The input boards are $25 USD each and is .062" thick and gold plated.

shipping to the lower 48 is $12 (up to 4 input boards) and international will be quoted per order. If you are in the NYC area I am happy to arrange something for pickup.

contact me with your oder and shipping info via info @ hakanairecording.com (please include your groupDIY name in the message)
Documentation for the new boards is being worked on right now but it is essentially the same circuit found below

documentation for this project (mark V) is here:

https://drive.google.com/file/d/0B1tn6X6wXoplRlVtTGRTeHI2QWM/edit?usp=sharing

thanks
Don

Remember, everything you do is at your own risk! including building this project
 
Stoked!

I'm in Greenpoint. I'll take the boards for a 16 channel mixer with pans. I'll get the caps too!

Thx for making these available.

Tim
 
The orginal boards look like 12x using 2 boards for 24 channels with everything in one case.
These being 8X Will 3 fit in a case with everything?
 
The boards are 4 x 9.5 inches. you can see here three of the new boards and the summing board in one case:

http://www.groupdiy.com/index.php?topic=41430.msg613409#msg613409
 
So, the 8 of these I purchased for my headphone mixers never got used for that purpose. However I finally found a way to use two of them to add amps and a fader to the bus returns of my desk. Right now there's a summing amp for the busses with a trim, then the insert, and then it goes directly to an LCR pan setup. So if you use the insert, or want to use those channels as additional returns, there's no amp and no fader. Looking at the 1608 service manual I realized I could copy the aux return amps (which were originally a 2510 as the line driver pre fader and a 2520 as the post fader amp) pretty much directly. There are a few small component changes. Anyway, thanks again for these boards Hakanai. The dream is to use the remainder of them, along with some ACA/booster cards, for a monitor section one day in the distant future.
 
This is a project that I would absolutely love to do at some point. I've been looking for something like this for a while. Would it be possible for you to post some A/B comparisons of summing a track with this box and without it?
 
Payment sent for 2 sets of pan boards and 2 sets of caps, got the main boards from you already.
Great project Don, thanks for putting it out there.

Ben
 
Hi Don,

3 input pcbs,3 sets pan pcbs and 3 sets of caps ordered and paid.

Thank you very much sir!

Cheers,

Udo.
 
I dont know if this has been covered somewhere else, but how many of these boards can be linked in total? A 32 input summing box or 2 bus mixer would be pretty slick! Or even better, since it's so modular, keep adding boards as needed kind of like a lot of the 8 channel fader packs with the ssl xdesks. Just start with a master section and the first 8 channels and expand from there.
 
I know Jeff has said the max number of channels that can be summed using his board somewhere on this board, but I can't remember off hand. Maybe check the ACA support thread. It is definitely over 32, but at that point I would probably be looking at adding a second bus (mostly for functionality sake).

don
 
Hello!

Is there any of the summing boards available at the moment?
(Or someone want to sell?)

I'd buy 2 of them.

Thanks!
Peter
 
Hey sorry to hear about the loss.  I've been hearing more and more from people that lost a great deal of musical gear.
Im not too far from you if you have things you need to work on, youre more than welcome to use my place till you get back up and running.
 
Ohh, I've just read the red line...

So sorry for disturbing with the PCBs....

Peter
 
Thanks guys. I have friends studio I can steal time from until I can rebuild and another friend who is a tech, so I can grab some bench time at his place as I need it. Hopefully I will be posting some good things here soon!

don
 
Hey prescott,

I have a few of the current boards left, but no pan boards. I am currently finishing up a revised version of the boards that will add some functionality you may or may not need. Please check out the original thread (linked above) to see the new features. If you would like to order the current boards let me know, otherwise I will update the thread here as the new boards become available.

thanks for the interest
Don
 
Question... Will this build work without the API ACA summing... I can't seem to find any info on whether it would work to just go out to a pre... I just want an active summing unit that is very basic and straight forward - If I can avoid going passive I will... I'm on a budget and a time-frame though; but then again, who isn't? I just want 2 boards, no pan pots, PSU, and maybe eventually I'll add a trim to each channel... Like I said, straightforward and simple  :)
 
are you going to be doing the panning boards again if not are the gerber files available so i can get some pcbs done
 

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