Mid Side Mini by ka-electronics "500 Series adaption"

[Bobby Baird]

Going to start this project this week. Since I haven't seen to many attempts at getting mid side encoding and decoding into a single 500 series rack space no less, I wanted to post this here in case others might find this adaption worth while for they're analog workflow. In's and out's are through front panel db-25 connector. 15 volt power handled by Jeff's card edge connector. I mocked up a panel I'll be ordering which is reversible in case you may want to mount horizontally. Attached is my panel design just change extention to fpd.

 

[moamps]

I would suggest using a Tascam AES pinout for the DB25 connector, where the first 4 channels are inputs and the second 4 outputs, so pre-assembled standard cables can be used.

 

[Bobby Baird]

My converter has TRS outputs so... People could wire this how ever they see fit. I just happen to have lots of gear that has trs in's and out's.

 

[Bobby Baird]

Some progress.

 

[electrosergio]

Are there updates? I am really excited, just started working on something very similar. Can you provide schematics of your PCB?

 

[Bobby Baird]

More Progress.

 

[Bobby Baird]

Are there updates? I am really excited, just started working on something very similar. Can you provide schematics of your PCB?

Boards here Mid Side Mini Simple MS Matrix
Schematic MS Mini - Mid Side Matrix Construction Information - Pro Audio Design Forum

 

[Bobby Baird]

Just need to wire it up.

 

[Bobby Baird]

Just need to check voltages before inserting IC's.

 

[Bobby Baird]

Finished.

 

[Bobby Baird]

Had a chance to run stereo track out to this matrix with G.Ten Eq for processing. Works as advertised. I had one issue. The db25 connector I had mounted behind the sled for easy panel swap to horizontal view was in-set to far in relation to the db25 connector standoffs, not allowing the snake to seat all the way down on the db25. So, I had to fish the wires through the panel and sled, so the db25 standoffs were at the appropriate level in relation to the connector. This just makes it a little more difficult to change panel view. Regardless, it was a fun project. Happy building.

 

[HerbertR]

Very clever, great idea....cheers ...If you want to use this board with the internal 500 In/Out XLRs you need to occupie two 500 slots....Hmmm... Yes........ I only want mention that for other builders ....

 

[fragletrollet]

Compact! Seems you still have room to implement a few toggles for the side boost and or mid attenuation?

I see what you mean with the DB25's, I have the same problem with my summing mixer that lead to a whole lot of troubleshooting just because the cable connection was somewhat compromised. Recently got my hardware for an expander I'm building, and was suggested to mill the panel behind the screws of the DB25 connector. Although the unit is still in build, the mechanics feel more reassuring when a cable is inserted and fastened than on the panel of my mixer. See pics in the thread here

I would also recommend the use of ferrules when using stranded wire and screw contacts, makes for a very reliable connection that doesn't destroy the wire with servicing. I really like this combo, and wish more pcb designers used it instead of the dreadful "Molex" style connector so often used, that is a pain to crimp and not nearly as reliable in my experience. I got Degson branded ones from Reichelt (I'm in Europe) instead of the Phoenix available through Mouser, considerably cheaper but feel great and sturdy.

Love the KA stuff. I got most of KA's pcb's, minus the lineamp and MC amps. 2x MTC's + MS2 + EEQ + 4x insert boards all soldered up waiting for a case, frontpanel and switches etc. Can't wait, but have a bunch of projects that I really need to finish first.

I also have the MS Mini, gonna use it in a D-AOC.