Mid Side M-S Matrix Construction Information

Construction information for DIY projects, including the MS Mid Side Matrix, Elliptic Equalizer, Mastering Console, Phono Transfer System, Insert Switcher and the Dual Class-A Amplifier. You can post your baby pictures here.
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poacherD
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Joined: Mon Nov 07, 2011 2:28 pm

Re: Mid Side M-S Matrix Construction Information

Post by poacherD »

raf wrote:
ricardo wrote:The Art of Electronics" - Horowitz & Hill
It will take you from basic Ohm's Law and you will still be using it when you are a true guru in your old age. :ugeek:
+1 on that!
Book is ordered! Can't wait to start learning a bit more efficiently.
raf wrote:
poacherD wrote:I had one last question, and it was in regards to the buying list - specifically, the 2 pin headers, and 8 pin sockets. I'm having a pretty difficult time figuring out which ones to buy, because I'm not sure which are going to fit.
Dylan
Hi Dylan,

The headers are Molex "KK" 0.100" pitch headers.
The 8 pin sockets can be any "soldertail" IC sockets. I recemmend dual leaf types as opposed to machined pin sockets since the dual leaf types have a much larger, more agressive contact on the IC pin. A lower resistance connection is good, low resistance is always good in contacts and ground planes! :D Speaking of which, the KK crimp terminals I referred to are the high vibration/ high pressure type.
Avoid using the smaller, cheaper Molex contacts for audio or power connections.


Here are some examples from Mouser Electronics...
Thanks Raf! This is a really great community you guys have here.

Thanks again for your patience - it's been a lot of help for me!
poacherD
Posts: 5
Joined: Mon Nov 07, 2011 2:28 pm

Re: Mid Side M-S Matrix Construction Information

Post by poacherD »

Gotta bug you guys one more time!

I finally finished assembly, and I'm now testing this bad boy.

So scratch everything I said previously. I've since discovered that it's a grounding issue. When the power supply is grounded, I get no audio signal. Could this have to do with my plastic chassis somehow?

I guess it's to the books to learn how to properly ground things!

The good news is that the actual signal flow of the unit seems to be working fine!

- Dylan
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mediatechnology
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Re: Mid Side M-S Matrix Construction Information

Post by mediatechnology »

When the power supply is grounded, I get no audio signal.
When the power supply is grounded to what?
klem
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Joined: Mon Jan 21, 2013 6:29 am

Re: Mid Side M-S Matrix Construction Information

Post by klem »

Here's my build with two of Sir Kirkwood's M/S boards, one for M/S, and the other as line receivers/drivers. The line receivers/drivers are on the right of the pic below. The switch on the right side is a DPDT with 2.21k across each of R4+5. When engaged, it gives an 8dB boost to channels 3+4. The M/S has mutes/solos for M/S from B insert (just before M/S output), and a variable width pot with a bypass switch all through insert G. I wanted to take the pot out of circuit when not needed; Wayne was kind enough to figure out how to implement this with minimal level disturbance, and posted the info here viewtopic.php?f=7&t=459#p6280 .

Both boards are powered off of one Meanwell tx (Jameco 237367). Roger recommended a 20 ohm wirewound resistor on the unused 5v line. Everything is dead quiet. Would love to take measurements, but such software isn't at the top of my 'to buy' list - I'd rather build Wayne's headphone amp!

Hats off to Wayne and Roger for sharing their knowledge and time with me. I learned far more than I expected to. Elegant circuit.
Attachments
WK MS line drivers guts1.JPG
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mediatechnology
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Re: Mid Side M-S Matrix Construction Information

Post by mediatechnology »

Thank you for sharing this! Great work.

Your build looks much better than mine - mine's just a board laying on the workbench. :oops:
I started using one board as a Soundcard test interface.
bigaudioblowhard
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Joined: Tue Mar 12, 2013 6:13 am

Re: Mid Side M-S Matrix Construction Information

Post by bigaudioblowhard »

sorry for the dumb question here folks, but what are you using for a power supply for the MS Matrix?

we have stuffed the board and are ready to test, and want to go full +/- 18v, as hi end as possible
as we will be using this in our pro mastering studio

a kit would be fine, we just don't know where to look?

thanks, _m
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mediatechnology
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Re: Mid Side M-S Matrix Construction Information

Post by mediatechnology »

For bipolar 18V I'd look at JLM or Five Fish. Those are adjustable.

http://www.jlmaudio.com/JLM%20Power%20Supply.htm

http://www.fivefishstudios.com/diy-kits/psu-2448mk2-kit

For bipolar 15 Roger recommends the MeanWell P50A-T series of switchers.

Roger and I used to have a kit. We sold a bunch of Picos but few power supplies which seemed odd...

The schematics are here: http://www.ka-electronics.com/PicoComp/ ... uments.htm
bigaudioblowhard
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Re: Mid Side M-S Matrix Construction Information

Post by bigaudioblowhard »

we went with the Five Fish Audio PS and PT kits. Nice products and great service from these folks. And went overkill with an external PS.
MS box fully up and running. We installed a DB25 connector to operate the unit from our mastering console which has spare unused switches and a DB25 on
the back. Heres how she turned out.
Screen Shot 2013-04-29 at 11.53.32 AM.png
Screen Shot 2013-04-29 at 11.53.32 AM.png (307.46 KiB) Viewed 21233 times
Questions here for what to use for relays.

1. I assume DPDT relays will work for balanced audio? Thats Pin 2 and P3 of each channel on each relay? Right?

2. we have 4 spare switches on the desk, so want to implement one each for Encode, Decode, Mute Mid, Mute Side, All switches off will be
full Bypass, I think 8 DPDT relays in all, no? Found this preassembled board on ebay, will it work?

http://www.ebay.com/itm/130670753670?ss ... 1423.l2649

thanks, m
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mediatechnology
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Re: Mid Side M-S Matrix Construction Information

Post by mediatechnology »

Very nice build. Thank you for sharing.
Questions here for what to use for relays.

1. I assume DPDT relays will work for balanced audio? Thats Pin 2 and P3 of each channel on each relay? Right?

2. we have 4 spare switches on the desk, so want to implement one each for Encode, Decode, Mute Mid, Mute Side, All switches off will be
full Bypass, I think 8 DPDT relays in all, no? Found this preassembled board on ebay, will it work?
Yes, DPDT is fine for switching pins 2 and 3 and that eBay board looks very useful to do it.

The mutes can be SPDT - half one of the DPDT - since those can be done single-ended.
Nescafe
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Location: Jakarta-INDONESIA

Re: Mid Side M-S Matrix Construction Information

Post by Nescafe »

Hi,

I'm new in this forum and have some question and need suggestion for implementing MS board in my application.
I will use the MS permanently in my tube compressor, the compressor itself is unbalanced both input and output.

Right now I put a balance input and output card before and after the compressor and have output transformer after the card.

After read the forum I realize that MS board can be use for balancing/debalancing too, so my question: is that OK to use MS board output to drive the output transformer?

Thank You
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