New RED BOXES - passive mix bus unit

[chrissugar]

Hi all

Finally I managed to finish some of my new projects, from the ones I posted at this thread:
http://www.groupdiy.com/FORUM/viewtopic.php?t=20788
This is my new passive summing unit. It is much, much simpler that my old summing box which included everything, including calibrated monitoring, speaker and input selector:
http://www.groupdiy.com/FORUM/viewtopic.php?t=13831
This new unit is as simple as possible, no knobs no level or panning option. Four channels are hardwired as mono, the others are stereo.
The advantage of this unit is that I can use any make up gain box compared to the old.
Also the lack of volume/pan control will help to make the projects more standard in asigning insturments/channels/buses from one project to another.
I added a feature to this box. I didn't include the resistor that determines the output Z of the summer (the resistor that has the mixed signal). This way I can change the value of this resistor depending on how many buses I want to use (phisicaly connect to the unit) in a project. The resistor is soldered inside an XLR female connector to pins 2 and 3. This way I can connect the right resistor for 8, 12, 16 or 24 channels depending on project.
I used only XLRs, no D-SUB connectors. I don't like those multipin connectors.


chrissugar

 

[ChrioN]

dude.

 

[skipwave]

Damn that's fine! :shock: Great idea for adjusting the output impedance based on the number of inputs used.

 

[SSLtech]

I hate you.

 

[Steffen]

u forgot the power inlet rookie! start over! :green:

 

[Steffen]

http://img.photobucket.com/albums/v292/chrissugar/BUSSMIX/MIXBUSS-2.jpg

wow! this looks ultraslick!

sometimes I wish I´d mix ITB

 

[ChrioN]

I would like to see a zoomed out picture of your entire diy rack :shock:

 

[chrissugar]

[quote author="skipwave"]Damn that's fine! :shock: Great idea for adjusting the output impedance based on the number of inputs used.[/quote]
There is also another advantage with this solution. With the right resistor/number of inputs, you have voltage-mode summing. But if you do not connect any resistor, with an adequate circuit, you can also implement balanced virtual-earth summing. :!:

[quote author="SSLtech"]I hate you.[/quote]
I hate you too because all those Studer 827s, SSL consoles, Bloo LA2As and Bloo 1176, you are surrounded with. Yes, I have lots of reasons to hate you. :grin:

[quote author="Steffen"]sometimes I wish I´d mix ITB [/quote]
ITB, you mean In The Box in Protools. You wish to mix in the devil's box? :twisted: Are you bored with summing in the analog world? :grin:
I think you mixed up the blue and the red pill. :green:


chrissugar

 

[Kit]

Thats sick.

Im curious, on the old unit. Where did you buy those cool knobs?

 

[chrissugar]

[quote author="Kit"]Im curious, on the old unit. Where did you buy those cool knobs?[/quote]

From www.okw.com
Here is the PDF for tuning knobs catalog http://www2.okw.com/PDFs/E/ST8130.pdf

chrissugar